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  1. Out in the public there is a tremendous need for this sort of thing. Most people I talk to think the weight of a gallon of gasoline vanishes when it is burned (how else could it float in the air as exhaust gas is their reasoning.)

    Comment by J.C.H — 5 Apr 2007 @ 10:06 AM

  2. I’m reminded of the story about heavy boots.

    Comment by Paul Dietz — 5 Apr 2007 @ 10:20 AM

  3. And there is all this hype about sunspot activity being the real cause behind global warming.

    Except it isn’t what is being claimed.

    Sunspots are a proxy for solar magnetic activity, and probably not a good one. Solar magnetic activity affects cosmic rays, that affect cloud formation, that affects global temperature.

    Sunspots do have an effect on solar radiation, but not enough to explain observered climate change

    Comment by Nick — 5 Apr 2007 @ 10:27 AM

  4. Such awesome magic, to know how to teach! Manifestly impossible, and yet people do it every day. Thanks to teachers like yourself, there just might be some hope for us after all.

    Comment by Daniel C. Goodwin — 5 Apr 2007 @ 10:28 AM

  5. Just a quick note to say Gavin wouldn’t let me put my acknowledgments in there, so I would like to publically thank him for his editorial support while writing this and the entire group at RealClimate for posting my commentary.

    I love the heavy boots story and I think I will use the gasoline just poofs into thin air when burned idea as a test in my class! And Daniel Goodwin, thanks so much for your kind words..

    Comment by Figen Mekik — 5 Apr 2007 @ 10:43 AM

  6. Really enjoyed the quiz, but I do agree the questions are sometimes misleading, and often nearly wrong (by failing to say “liquid water” for instance, they ignored the huge amount of water in minerals).

    Comment by P.C.G. — 5 Apr 2007 @ 10:54 AM

  7. It’s tough, because if you say scientists (or even teachers) are infallible, you get caught out in the end, because they aren’t infallible (obviously). On the other hand, if you talk about the fallibility of science, or come across a teacher or scientist who gets something wrong, then people always assume that they are wrong.

    About the quiz, I agree that some of the questions were misleading, although I only really spotted 2 that were Chicago-centric. Some of them (like the one about the steel boat) were worded in a confusing way, in that I got my answer wrong, but in reading the ‘right’ answer I realised that was what I actually meant. Curiously, I did better with the biology questions than the physics ones, even though I dropped biology after 10th grade and kept on with physics all the way through. I suppose they were more straightforward.

    Comment by tico89 — 5 Apr 2007 @ 11:26 AM

  8. We know–and teach–too much theory, and too little practice–too much sitting in class, too little getting hands dirty. But ultimately “science” is organized practical ideas, and theories derived from them.

    Comment by Randolph Fritz — 5 Apr 2007 @ 11:27 AM

  9. That was one of the worst K-6 no child left level quizzes I have ever seen. Just about every question had three answers on a true false basis.

    Comment by Eli Rabett — 5 Apr 2007 @ 12:51 PM

  10. Several of the questions have odd corner cases. E.g., I believe that there is animal life living by underwater smokers that does not live on plants. Also, if it turns out that there is a cosmological constant, then the energy in the universe is indeed changing as the universe expands. And technically, if dropped outside a vacuum, the heavier sphere does hit the ground first. Different wavelengths of light also travel at different speeds when not in a vacuum. etc.

    There’s some awkward wording in a couple sentences, too. (I read nutrient to include CO2 and O2, for example)

    Comment by Marcus — 5 Apr 2007 @ 12:55 PM

  11. What a wonderful post. The students at GVSU are getting their money’s worth in Prof Mekik’s courses.

    P.S. Lack of credentials in education psych is a badge of honor in many circles.



    Comment by Martin Hackworth — 5 Apr 2007 @ 1:11 PM

  12. I’m with Martin – beautifully written article and the kind of thing that needs to run in local newspapers so people learn about these things. In fact, why not shop it around?

    Janis Mara

    Comment by Janis Mara — 5 Apr 2007 @ 1:15 PM

  13. The quiz was interesting, but some of the questions will foul up a real scientist. For example, they ask whether a metal ball hits the ground before a wooden ball of equal size and similar surface, when dropped from the same height. Of course I said it would, because the air resistance has more impact on the wooden ball (the difference is slight but not zero). But they scored me wrong.

    They didn’t say “in a vacuum”!

    Comment by tamino — 5 Apr 2007 @ 1:27 PM

  14. ps. I do think that this kind of effort is very important. I did take a secondary school science teaching course in which we watched a segment of the Private Universe video, and which stressed inquiry based learning as a very valuable tool… with the drawback being that the rate of information transfer is much lower. You can’t teach _everything_ in a hands on exploratory fashion because there is just too much that needs to be covered, and for some things it is necessary to accept “the scientific consensus” and move on without thinking through it. But it is good to try and give as much intuitive understanding through a hands on approach as is practically feasible.

    Comment by Marcus — 5 Apr 2007 @ 1:29 PM

  15. r.e. the quiz, the physics questions are pretty bad. Particularly egregious is the one that asks whether the heavy ball or the light ball falls faster without specifying whether they’re falling in a vacuum. Many of the others have as the correct answer that an effect does not exist, when in fact it’s just very small.

    Comment by Ross O'Connell — 5 Apr 2007 @ 1:40 PM

  16. Seed germination — which particular seed?

    “The Calvaria tree, on the Mauritius Islands, was totally dependent upon the dodo bird to ingest its seeds, scarify its hard coating, and excrete the seeds before germination could take place. Since the dodo bird became extinct in 1681, no reproduction of this tree has taken place. In fact, the youngest trees are 300 years old!”

    Seed germination and moonlight:

    Comment by Hank Roberts — 5 Apr 2007 @ 2:45 PM

  17. great post. However, I have serious problems with the quiz. I found bad wording in almost every question, most of which have already been mentioned, but I also object to their assertion that people living in Hawaii don’t count (it’s in the tropics, so the sun does go overhead). Oh, yeah, and air friction is a force, not an acceleration, so their attempt to say that the different spheres were the same shape but different weights and hence would experience the same deceleration from friction is bogus, the heavy ball will hit first because its inertia can fight the air friction better as its accelerated by gravity at a constant rate– the air friction’s fighting F=ma, not just a.

    However, I have a much worse problem with the quiz. I found it, not by chance, but by following a friend’s journal link that led to this post, which led to the quiz. So whatever results they get, they don’t reflect the “general population,” they represent the types of people who find and follow links to science quizzes and decide to take them. So the science of their study is inherently flawed by bad sampling, and the demographic questions at the beginning really didn’t do much to address that: I am not currently a student or a teacher, so I’m just “other,” but I’m sure I’m disproportionately represented by being the kind of person who people forward science quizzes to.

    I’m also a cynic in a grumpy mood, as is probably obvious. And, I did learn some things, so it was fun, I just enjoy nitpicking.

    Comment by Mark "Monty" Montague — 5 Apr 2007 @ 2:56 PM

  18. I would consider that 11 of the 47 questions have a serious flaw either in concept or language, or both. This is very sad. These are the basic processes that operate in the universe. It should be simple to ask questions that determine whether a person understands a given process or not. This quiz says that among the test makers, the English majors do not understand good science and the scientists do not write good English.

    When I was a student, on an â??open bookâ?? exercise, 36/47 was a flunk. The idea for this quiz is great. However, the execution is seriously flawed.

    Comment by Aaron Lewis — 5 Apr 2007 @ 2:56 PM

  19. Schema and mental model theories in cognitive pyschology and artificial intellegence deal extensively with naive physics, astronomy, biology, etc..

    Here’s a classic paper done on observational astronomy.

    Comment by Tavita — 5 Apr 2007 @ 3:12 PM

  20. Two anecdotes of my own plus an admission of my own ignorance:
    . 1. Camping outside of Edmonton in my youth, my older brother’s friend reported that the beer was frozen but don’t worry, he’d wrapped them in a blanket to thaw them faster. I probably never felt smarter than when I explained his folly to him.
    . 2. Unbelievably, a friend in university blurted out without thinking that thunder was caused by clouds banging into one another. After noticing everyone’s jaws drop he remembered where the sound came from, but what his parents told him when he was ~5 still had primacy. (I confess that I probably would think that hiccupping indicated growth for the same reason, except my remaining short made me very skeptical.)
    . Admission: I still don’t understand the Coriolis effect. I draw the Pacific Basin, imagine the Earth rotating to the East, and then I can envision two big gyres (clockwise in N hemisphere and counter- in S hemisphere) forming. I think my problem here is I presuppose that rotation of the Earth is causing movement of the water, whereas the unimaginative side of my mind tells me that the Coriolis effect is only about frame of reference.

    Comment by Steve Latham — 5 Apr 2007 @ 3:19 PM

  21. Yes, that quiz was pretty lousy in many ways.

    They say that the total energy in the universe is constant. This is only (perhaps) true if you use the word “energy” as including “mass”. Which is not always done.

    They also say that the total mass after a chemical reaction is exactly the same as it is before. This is just wrong. Chemical reactions can be exothermic or endothermic, and convert some mass to heat or vice versa.

    There are other difficulties, as well, but these two stood out for me.

    Comment by Brian — 5 Apr 2007 @ 3:39 PM

  22. What is the density of a volume of air that contains fog droplets? How does this compare to the same volume that is entirely gaseous?

    Comment by NeilS — 5 Apr 2007 @ 4:02 PM

  23. On the perception that blankets warm things–I asked my 8 year old daughter if a bowl of ice would melt faster or slower if we covered it with a dish cloth. She said faster of course, because the “blanket” would warm the ice. So we did the experiment, but she lost interest by the time the result was clear! Mostly I teach 18-22 yr olds, but they’re not a lot different.

    Comment by David Eubanks — 5 Apr 2007 @ 4:20 PM

  24. Regarding the quiz, like Marcus I took ‘nutrients’ to include atmospheric gases. I took my time typing up my explanations which meant that I was getting tired and a bit sloppy towards the end which led me to misread some of the statements or forget to change the TRUE/FALSE selector.

    Also I’d say that the electrical light bulb question is more a test of lateral thinking than understanding of scientific principles, but then I got it wrong so I would say that, wouldn’t I?


    Comment by Luke Silburn — 5 Apr 2007 @ 4:29 PM

  25. Questions 19 and 20 seemed too much like trick questions. I knew the principles and explained correctly but, due to the ambiguity of the questions, got them wrong.

    (Spoiler: Don’t read the next bit if you want to take the test).

    #19: It is possible to light a flashlight bulb with just one wire and one battery and no other equipment.

    I answered false, saying you need a second wire to connect to the other battery terminal and complete the circuit. While that isn’t absolutely necessary, I figured that was what the question was getting at–having a closed circuit. Instead, the answer says that you could just touch the other end of the battery to the bulb’s contact–which is fine, but at that point you’re getting kind of specific and not testing the principle so much as a neat shortcut to hooking up the lightbulb. Someone could answer “true” thinking that just running a single wire from one terminal of a battery to a light bulb would power it–and they would be told that they’re correct.

    #20: We (humans) need light in order to see.

    I answered false. We see regardless of whether there’s light or not. If there’s no light, we just see nothing. But our brain and eyes are sitll working just fine. How about rewording it to say “Humans need a light source to see something?”

    Comment by Bolo — 5 Apr 2007 @ 4:32 PM


    Comment by Hank Roberts — 5 Apr 2007 @ 4:40 PM

  27. Do you want the dry density or the wet density? wry smile.
    Start early and teach things chronologically. I learnt my science many many years ago on my mother’s lap. We didn’t call it meteorology or climate science in those days. On the first day the sun, the brilliant shining one rose. Everything he named came into existence. He whispered Shu and the wind blew. Tefnut and the rain spittered. Geb and the ancestral earth rose above the oceans. Nut and the vault of the sky appeared above the horizon.
    We abhored experiments and vacuums in those early days.
    Does a wooden ball fall faster than a metal or a rock ball? The first experiment was proposed to be carried out at Karnak or Abu Simbel, I forget which; the experiment was forbidden, for reasons too lenghty to be described here. Imagine that either one did fall at a faster rate.
    Conceptually tie a plumb line to connect them. Drop from a great height. Surely if the wooden ball fell more slowly than the metal one the string would become taught and retard the fall of the metal ball. Hence, both balls combined, and more massive than either separately, would fall more slowly than the metal ball. Surely if the wooden ball fell more swifly than the metal ball the string would become taught and the wooden lighter ball would increase the speed of the metal ball but not so quickly as the objects separated.
    Of course we didn’t know in those days that the atoms themselves were joined by tiny “springs” but we did know logic, that all things fell at the same rate whether combined or not.

    Comment by g.dungworth — 5 Apr 2007 @ 5:01 PM

  28. I agree the quiz was fun, and some potential areas for fixing it to become more usable/accurate:

    2. Plants use oxygen. -> use is a bad word hear, especially in such a short question, as I treated it as if it had the meaning ‘consume’ (which I think is a valid reading, given limited context).

    19. About the wire/battery/bulb seems more designed to be a trick question that trying to work out understanding of the science involved.

    22 About the difference in velocity of different energy wave forms – presumably this needs to add ‘in a vacuum’ or similar language as has been mentioned in other comments.

    A number of the others I guessed that some of the minor effects probably werent expected to be known (such as the steel and wooden ball being dropped arriving at the same time, which as we know is an oversimplification), based on that the primary audience seemed to be school age children from the introduction.

    In all I think I got 2 wrong due to not knowing or applying the science, one wrong from not knowing the geography/geology (I thought Chicago was well away from any major plate boundary, guess not), 1 wrong because I didnt select the right option from the TRUE/FALSE bit despite filling in almost the same description as given more or less, 1 wrong from lack of reading comprehension, and 3 wrong because the questions mislead me despite understanding all the elements required.

    Probably overall thats not too bad in terms of misleading questions (have seen much worse quizzes than that by far), but maybe you can use some of the above to improve it.

    Comment by stuart — 5 Apr 2007 @ 5:50 PM

  29. Economists have conducted studies on situations where there is asymmetric information–either the buyer or seller knows much more about the item for sale. When this becomes clear to both, a transaction becomes much less likely. I think in some ways the asymmetry of expertise between scientists and at least some laymen has a similar effect–especially if the laymen already question scientists, or even experts in general. Culture also plays a role. Anglo-Saxon culture is full of folk tales in which the yokel gets the better of his betters. The yokel is usually named Jack, and “Jack and the Bean Stalk” is one such tale. Also look at “The Marriage of Figaro” or some of Shakespeare’s comedies. In general, the less people understand about a subject, the more likely they are to fear being misled.
    Ironically, this fear can be even greater if the “layman” is educated in some specialized discipline, but not, say, in climate. In this case, much of the ego of the layman may be tied up in considering himself intelligent–and not to tell him he doesn’t understand something may be considered an affront. I think it was Mark Twain who said, “What gets us into trouble is not what we don’t know. It’s what we know for sure that just ain’t so.”

    Comment by Ray Ladbury — 5 Apr 2007 @ 6:24 PM

  30. It may be piling on but I have to add my voice to the other quiz nitpickers. It was entertaining but some of those nits are pretty big. The ‘correct’ answers to questions 12, 16, and 21 are simply wrong. For 16, think about the results if the spheres are identical balloons, one filled with helium, the other with CO2. Same size, same surface, different masses. Release them in a vacuum (and yes, I know the balloons would pop in a vacuum) and they would land at the same time. Release them on earth and guess which one lands first. :-)

    As for 21, of course it makes a difference, go find a mirror and see for yourself. As you get closer you can’t see all of yourself, as you back away you can see more. But the difference isn’t due to the mirror but rather the eye’s field of view. You get the same effect with a live person as with your reflection.

    Whew, I feel much better now so I’ll quit venting. Other than the quiz it was an excellent column.


    Comment by Phillip Shaw — 5 Apr 2007 @ 6:45 PM

  31. “I try to dispel this misconception by explaining that though the sun is indeed quite hot, there is all this empty space between the Sun and our planet and heat canâ��t travel through a vacuum, but light can!”

    That is a really bad science explanation,and fundamentally incorrect.

    Solar energy is radiated into space mainly in two forms, as electromagnetic radiation energy over a wide range of wavelengths, and as kinetic and thermal energy of the solar wind plama.The former freely propagates through the interplanetary space,and only undergoes some changes and transformation in the atmospheres of the earth and of other planets. In contrast to this, the soar wind plasma energy is continually transferred from one form to another.

    In extra vehicular activities the greatest problem facing astronauts is overheating.

    Comment by makarov — 5 Apr 2007 @ 7:52 PM

  32. Thursday is a long teaching day for me, so it is quite a pleasure to come out of class and find so many comments. I will try to respond to what I can.

    First, many thanks to all your compliments about the post. I certainly enjoyed writing it, and I am enjoying the feedback I am getting more.

    About the quizâ?¦ Some people started sort of apologizing for picking on it, but by all means pick away. It is the best quiz of its sort that I could find on line but I didnâ??t do very well on it myself, mostly because of the things that the commenters have already pointed out. The seed germination question killed me. And I didnâ??t really feel the quiz was testing grand misconceptions about science. So why did I put it in my post? I thought it would make a good conversation piece and it is one of the better ones out there that I was able to find (Iâ??m very open to suggestions about better ones). Itâ??s tough coming up with good exam questions. And by the time you perfect your exam, too many students have taken it, so you have to make a new one! :)

    About inquiry-based hands on learning. I agree with Randolph Fritz (#8) that we should do more hands-on work with students, but I also agree with Marcus (14) in that you have to pick your battles wisely. There are only 14 weeks in a semester, and if you are in a school on a quarter system, thatâ??s just 10 weeks per quarter. There is lots of material to cover. I also find that each class has a personality of its own and have their own misconcenptions. So you canâ??t really do the same hands on activity in every class because that may be old news to some who are really confused about something else. Plus I had one class of ~20 who did not say a word to me or to each other the first 10 weeks of class. It was really freaking me out. Finally I made them give oral presentations just so they would investigate something and talk about it.

    Steve Latham: The day that I actually understood the Coriolis effect in all its simplicity, I called my dissertation advisor in the middle of the night, woke him up and told him all about it. It was definitely a momentous occasion for me!

    Ray Ladbury: I wish I could translate Mark Twain into Turkish as eloquently as he is in English! Thatâ??s a great quote. The problem with these misconceptions is that people have no idea they have them.

    Tico89: Youâ??re absolutely right. I worry a lot about perpetuating misconceptions I have or creating new ones in the classroom. One thing I have on my side though is fatigue. I am usually so sleep deprived that students are used to my little mistakes and foibles. And Iâ??ve found that if you show you are willing to admit you were wrong or made a mistake and try to learn with them, they are very receptive and forgiving with that. Plus sometimes it gets them to â??take the leadâ?? and they never forget something they work out for themselves!

    Comment by Figen Mekik — 5 Apr 2007 @ 8:30 PM

  33. I have to echo comments 9, 10, 13, 15, … , 25, etc.

    Some of the things I was going to say have already been said, but here are a couple additions:

    6 Aside from the issue of chemoautotrophs, are phytoplankton and macroscopic algae like kelp considered to be plants? I thought they were considered to be in a different grouping. Then again, where do liverworts and mosses (no vascular system) fit in – I would call those plants. Kelp is multicellular, so if that’s not a plant, then maybe moss shouldn’t be a plant either – that doesn’t seem right. Need to look at phylogenies for guidance…

    21. Yes, I got that wrong – because I was thinking of the mirror in my bathroom, which is not a full length mirror. The question should specify that it’s a full length mirror.

    Comment by Pat — 5 Apr 2007 @ 9:11 PM

  34. Great post – the quiz was interesting if ambiguous. Now, if someone could come up with a similar true/false quiz related strictly to climate issues:

    Global ocean heat content has increased over the past three decades.

    The Greenland and West Antarctic Ice Sheets are losing mass.

    Drought in the Amazon, Africa, the American West and Northern China is due to anthropogenic climate change.

    Anthropogenic global warming is changing ocean circulation patterns.

    Burning fossil fuels has resulted in a moister atmosphere.

    Increases in hurricane intensity are closely linked to anthropogenic climate change.

    Sea level will rise faster than expected due to ice sheet dynamics.

    Climate models produce realistic estimations of future climate change over the next century.

    Halting the use of fossil fuels will result in the stabilization of atmospheric CO2 levels.

    True or false? That’s the problem with true/false and multiple choice tests – sure, they’re easy to grade, but the real world is full of nuances, exceptions and conditional factors. Science education involves too much memorization of the ‘right answer’, and not enough about how to find out the answer, or how to sort out conflicting claims. Here are a few more true/false questions of importance:

    Climate change will have devastating effects on human civilization under business-as-usual scenarios.
    Climate change will have ignorable effects on human civilization under business-as-usual scenarios.

    Energy choices made today will have a large effect on future climate change.

    Comment by Ike Solem — 5 Apr 2007 @ 9:51 PM

  35. What gets me is people who say: “Who cares? we won’t be around in 50 years or so, after we die, so who cares?”

    and Diesel with its Global Warming Ready adverts?

    What’s up with that?

    Comment by Danny Bee — 5 Apr 2007 @ 10:34 PM

  36. Questions #3, #5, #32 are just clearly so wrong.

    #3 – There are many examples of seeds (like the Dodo one given above) that need “special” conditions – like exposure to digestive chemicals, exposure to light, etc.

    #5 – Animals that feed on animals that feed on bacteria don’t need plants. Not many. But certainly counterexamples exist.

    #32 – So obviously wrong its embarrassing.

    #23 That is actually an open question.

    #24 That kind of depends on your definition of orderly. If the universe expands forever, heat “death” is the result (seems boringly cold and orderly to me). If the universe contracts to a singularity, what could be less chaotic than THAT?

    #35 is wrong. When since is air pressure (density) purely a function of humidity? Yeah – they are related. But there’s that temperature thing. Cold, humid day in October can have higher pressure than hot, dry day in July. Wind movements can certainly cause pressure anomalies etc. Then there’s the baseball. Dry and humid baseballs are NOT the same. In humid conditions, a baseball absorbs water and becomes heavier, bigger and mushier. A dry baseball is smaller, harder and lighter. Hence dry baseball can go further. In fact, air conditioned baseballs used in humid stadium, go YARD!

    Comment by Robin Johnson — 5 Apr 2007 @ 11:09 PM

  37. i would also like to comment on the quiz. question 32 ignores binding energy which is a component of the mass of a compound.

    Comment by Thomas Folz-Donahue — 5 Apr 2007 @ 11:24 PM

  38. Great post.Many of the questions were not well-written for anyone with a science background. However, I have problems with questions 10 & 25.

    Question 10: There is still an ongoing debate over whether a virus is a living organism. A virus does not have a cellular structure.

    Question 25: 2 objects of different temperature in a vacuum do not transfer heat energy from the warmer object to the cooler object until they reach equilibrium. Reference the Sun and the planets.

    21 was also a field of view thing for me. Other than that, the other mistakes were in reading.

    Comment by Peter P — 5 Apr 2007 @ 11:52 PM

  39. Ike – I think the answer to every one of your questions is: unknown.

    Comment by Steve Reynolds — 5 Apr 2007 @ 11:58 PM

  40. Book: “Kicking the Carbon Habit” by William Sweet
    There is a factual error on page 185 of this book. He says that there were 2 nuclear explosions in the Chernobyl accident. There was no NUCLEAR explosion in the Chernobyl reactor because that is physically impossible. Chernobyl was a DIRTY bomb. Chernobyl was NOT a NUCLEAR bomb. He confused nuclear with dirty. This is probably a popular confusion. Most people probably made the same error. The big mistakes were saying the scientists and engineers were wrong and not asking the scientists and engineers for explanations. There was a CARBON fire or possibly a carbon powder explosion. A nuclear explosion would have levelled the complex and quite a lot more. The Chernobyl reactor was carbon moderated. Carbon is used to slow down the neutrons so that they are easily absorbed. Western-built reactors have always been water-moderated except for the very first reactor ever built. Coal is carbon. Uranium is pyrophoric, which means that uranium burns [oxidizes] at the slightest excuse. A uranium fire would ignite the carbon. If the carbon was powdered it would explode like dust in a grain elevator, but I don’t know whether the carbon was powdered or in big lumps.
    Why a Nuclear Powerplant CAN NOT Explode like a Nuclear Bomb:
    Bombs are completely different from reactors. There is nothing similar about them except that they both need fissile materials. But they need DIFFERENT fissile materials and they use them very differently.
    A nuclear bomb “compresses” pure or nearly pure fissile material into a small space. The fissile material is either the uranium isotope 235 or plutonium. If it is uranium, it is at least 90% uranium 235 and 10% or less uranium 238. The bomb must compress the uranium or plutonium because a bomb has no moderator to slow the neutrons down. These fissile materials are metals and very difficult to compress. Because they are difficult to compress, a high explosive [high speed explosive] is required to compress them. Pieces of the fissile material have to slam into each other hard for the nuclear reactions to take place. In plutonium bombs, the high speed explosive has to be precisely shaped and has to explode from all sides simultaneously to make the bomb work. There is no way an accident could get the explosive to explode correctly. In gun-type bombs, there must be a gun barrel to direct one piece of uranium into the other piece of uranium at high speed and with precise direction. There is nothing precise about an accident.
    A nuclear reactor, such as the ones used for power generation, does not have any PURE fissile material. The fuel may be 2% uranium 235 mixed with uranium 238. A mixture of 2% uranium 235 mixed with uranium 238 cannot be made to explode in the nuclear way no matter how hard you try. A small amount of plutonium mixed in with the uranium cannot change this. Reactor fuel still cannot be made to explode like a nuclear bomb no matter how hard you try. There has never been a nuclear explosion in a reactor and there never will be. [Uranium and plutonium are flammable, but a fire isn't an explosion.] The fuel in a reactor is further diluted by the moderator, which is carbon at Chernobyl or water everywhere outside the Soviet Union. We use water as the moderator because water can’t burn. The fuel in a reactor is further diluted by being divided and sealed into many small steel capsules. The fuel in a reactor is further diluted by the need for coolant to flow around the capsules and through the core so that heat can be transported to a place where heat energy can be converted to electrical energy. A reactor does not contain any high speed chemical explosive as a bomb must have. A reactor does not have any intentional explosive materials at all.
    As is obvious from the above descriptions, there is no possible way that a reactor could ever explode like a nuclear bomb. Reactors and bombs are very different. Reactors and bombs are really not even related to each other.
    But just ask the average person about this.

    Comment by Edward Greisch — 6 Apr 2007 @ 3:30 AM

  41. We burn all that coal to make electricity because most people think nuclear power is dangerous. They have never heard of background radiation. They don’t know that ancient mummies are dated by radioactive carbon. They don’t know that coal-fired power plants put enough uranium into the air to fully fuel our nuclear power plants. They don’t know that coal also contains arsenic and thorium and every natural heavy metal poison.
    The question is, how are you going to cram enough knowledge into unwilling heads by the end of 12th grade to make good citizens? I think we should start by requiring ALL college students, even English, drama, sculpture and elementary teaching majors, to take the “Engineering and Science Core Cirriculum”.

    Comment by Edward Greisch — 6 Apr 2007 @ 3:41 AM

  42. I’m a grown man, self employed and so on. I dropped out of 8th grade, and obviously haven’t done too bad for myself.. But taking that test and having to explain how I think things work, I realized my knowledge of how nature is put together, is not knowledge at all, but rather a gaping black abyss.

    I read RC with some regularity, and even understand bits of it when the weather’s right and the sun’s in my back. And one of the things I’ve noticed, is that a lot of terribly knowledgeable science nerds frequent this place. So what better crowd of random strangers to ask.

    How do I learn? Where do I start? Between job, family and my shocking lack of education, going back to school isn’t really a possibility, I think. But what books did you lot chew through in school? Which do you throw at your students?

    Please take a moment to help me out if you can. The curiosity is killing me. I’ll bookmark this and check back regularly the next week or two. Sincere thanks in advance. I hope you never have to confront your ignorance like I just have. It’s ghastly.

    Comment by Kaoten — 6 Apr 2007 @ 6:19 AM

  43. I make it that the quiz has 10 wrong answers. I only ‘missed’ nine because I purposely put down the wrong (but obviously desired) answer once.

    Aside from the others mentioned, sexually produced offspring can be identical to their parents. If the parents have exactly the same DNA then, barring mutations, the offspring will have exactly the same genes as both parents. Note that while mammals of different sexes cannot have identical genes, this is not true of all animals. Of course, even mammals can have exactly the same genes as one of their parents, since there is a chance as long as one parent has a match for one of each of the other’s chromosome pairs.

    Comment by Greg Simpson — 6 Apr 2007 @ 7:02 AM

  44. heat can’t travel through a vacuum

    Everything above zero Kelvin radiates energy (i.e. heat). It travels pretty well through a vacuum, and depending on the frequency of the radiation, through other materials too. There is no fundamental difference between light from the sun at visible frequencies, big-bang leftover radiation at infra-red, or even x-ray radiation from other processes. If the radiation is absorbed, the temperature of the absorber rises a little – in a steady state scenario it rises until the energy radiated is the same as energy absorbed. NB this does NOT mean the temperatures have to be equal. Besides passing through or being absorbed there is another possibility – the radiation can be reflected

    [Response: Thanks. We updated the text to reflect reality. Another linguistic confusion I think.... - gavin]

    Comment by John Ryan — 6 Apr 2007 @ 7:05 AM

  45. Kaoten: Even scientists at the pinnacle of their careers with degrees from prestigious schools are confronted with their ghastly ignorance about something every day. The trick is in recognizing this; and the arrogance is in ignoring it. So, some of my favorite books are Longitude by Dava Sobel, Our Enchanted Affair with El Nino by George Philander, and if you want a solid introductory text book about climate science I would recommend William Ruddiman’s Earth’s Climate Past and Future. Also if you just want to focus on global warming give David Archer’s Global Warming: Understanding the Forecast a read..

    Ike Solem: that’s a mean quiz!! :)

    Comment by Figen Mekik — 6 Apr 2007 @ 7:27 AM

  46. Thank you for this fine post. It brought to mind the late Neil Postman’s writing on language and stupidity. An example: he relates the story of a student who, in an unusually warm classroom, asks what the temperature is. Upon being told, the student exclaims, “No wonder it’s hot in here!”

    Comment by Taylor — 6 Apr 2007 @ 8:00 AM

  47. and if you want some interesting stuff about our sun, dip into
    Kinda makes you think..

    Comment by Nigel Williams — 6 Apr 2007 @ 8:14 AM

  48. Kaoten, I applaud your interest. A warning: thirst for learning is an incurable disease. Once you start, you’ll never be sated. As near as I can tell, though, it is a disease that only brings benefits.
    The first question I have for you is: What is it you want to learn? You will have much more success getting through the inevitable dry parts of any subject if you know you’ll be rewarded with understanding something that interests you down the road.

    As far a a program of general learning, I don’t think you can go wrong with starting with language and math. WRT the former, the book “Eats shoots and Leaves,” is a delightful book. I’m not sure I know of a really good, fun math book. Maybe Polya’s “How to solve it” comes closest. Anyone else have suggestions?

    Here’s a chance to plug one of my favorite books of all time: “The Flying Circus of Physics,” by Jearl Walker. Short little blurbs about all of the amazing little miracles of our daily world. You will never look at the sky, ocean or a cup of tea the same way again after reading this book. BUY IT NOW! is my strongest suggestion. Good luck and feel free to contact me offline as your program progresses.

    Comment by Ray Ladbury — 6 Apr 2007 @ 8:32 AM

  49. Concerning stuff to read: as a teen I got a copy of VW Maintenance for Compleat Idiots. What a godsend. I never got training in car maintenance but even I could do most of the work on my car with such a book to help. Similar things are also the best intro read in many other subjects as well. The cartoon series XXX For Beginners comes to mind. For physics there is The Cartoon Guide to Physics by Larry Gonick. It is about really basic physics. No theory of everything jazz, just the basics like classical mechanics and thermodynamics and the like that affect things most people come in contact with. It conveys the ideas through cartoon stories which are designed to help you understand things. They’re also entertaining but are done without the wow gee whiz factor you get in those theory of everything books whose effect is mainly to mystify, not to teach. I can really recommend this one for people who want the basics, about everyday things but also done in a conceptual manner, not through factoids.


    Comment by Bruce Scott — 6 Apr 2007 @ 8:32 AM

  50. Re: The Quiz. Its interesting that the Quiz is a very nice example of all the things Figen Mekik is trying to address, and RC too. Imprecise language about mirrors, genetics, mass and energy lead us into a mire. If its ‘only’ intended to be ‘popular science’ then at least get the questions right; if is supposed to be real science, then we need to see that the science behind the answers is right too.

    The quiz measures something, but I think that the only useful knowledge we can learn from it is about the quiz master. The quiz is flawed in its sampling methodology, and at least 20 percent of the question-answers are wrong. Any data arising from the quiz about the intelect of the quiz participants its useless.

    Comment by Nigel Williams — 6 Apr 2007 @ 8:36 AM

  51. I’m aware of studies that show the ozone-GW confusion…and people thinking all they have to do is stop using hairspray (which no longer has CFCs in it anyway) to halt GW. In fact I gleaned that from a study I did on General Social Survey data around mid-90s.

    One of the problems mentioned is that these 2 problems happened close in time to each other (& they both involve the atmosphere). You have to understand that most people don’t pay avid attention to the news, and the newsperson may even get things wrong. So they hear snippets as they walk past TV stores or from someone’s radio on the bus. And they use their existing world view to cobble together something that makes sense to them.

    And, shame shame, they really should have paid more attention during high school science class, so they’d have a better foundation on which to build.

    And unfortunately the height of respect for science was in the 50s & 60s (I remember listening to Sputnik’s dog’s heartbeat for an hour in my 6th grade class — science was king, I was going to be a scientist), and now respect for science has waned, with attacks from the religious right, the post-modern academic elites, and industry getting its act together after Rachel Carson’s SILENT SPRING broadside. And all the “science” being done by creationists and industry wonks (some of whom are even imprisoned for out&out fraudulent science) has only fed into a general disrespect or at least enlightened skepticism about science. Like, who’s to believe the latest Chocolate Industry study that chocolate is good for the heart (or those “studies” they allude to in TV commercials). No one likes to be taken for a dupe.

    Then there is the way statistics are presented. So, if I say “there’s a 20% chance you will be in a car accident over the next 10 years driving around Chicago,” that sounds a whole lot worse than, “there’s an 80% chance you will not be in a car accident over the next 10 years driving around Chicago.” And unfortunately the way hypothesis testing is set up focusing on the null hypothesis….well, it makes GW & other environ problems seem not so bad. Afterall, there’s a five percent chance nothing’s happening. We’ll take our chances.

    Comment by Lynn Vincentnathan — 6 Apr 2007 @ 9:31 AM

  52. Greg makes an important point, anykid with half a brain after taking all the “high stakes” multiple choice tests learns that she is smarter than whoever wrote the test and how to game the system. With certain teachers, you learn that it is a lot easier to give the right wrong answer than to try and engage in a dialog, kid version:god you’re stupid teach, teacher: you flunk and I want to see your parents.

    Lots of bright and normal kids have learned that that the way to an A is to find the answer that the test wants, which is not the right answer.

    The net result is you build a society of the collegekids who Figen and I teach.

    Comment by Eli Rabett — 6 Apr 2007 @ 9:36 AM

  53. Kaotin, I put three climate on-line texts on my blog roll, and a number of tree killer text books can be found in a post There are some reviews in the comments, especially with respect to difficulty. I have to get back to complete the circle by listing atmospheric chemistry and biogeochemistry books.

    Comment by Eli Rabett — 6 Apr 2007 @ 9:47 AM

  54. This is a comment for Kaoten regarding number 42. Go back to school. I always wanted a science degree and I started back to school in my 40s, while working full time at a physically difficult job. When I was on the night shift I took my 10 minute breaks and studied my calculus. I had to start my math series way back at intermediate algebra because I lacked a good high school education. It was very difficult, but by the age of 55 I had a masters degree in Geology with a good solid foundation in math, chemistry, and physics. It has changed my life and I did this for myself so that I could better understand our world and the changes that we have made to it.


    Comment by Elizabeth — 6 Apr 2007 @ 9:58 AM

  55. >There was no NUCLEAR explosion in the Chernobyl reactor …

    However, a nuclear reactor has far more and varied radioactive material in it than a nuclear bomb, and even a very dirty ground or underwater nuclear bomb explosion puts far less radiation into the environment than failure of containment on a reactor that’s been operating for a while and is full of transuranics.

    Look how hard they’re working to keep the Chernobyl-type reactors operating, eh?

    unfortunately the original PDF isn’t showing up, this gets you the HTML version

    Comment by Hank Roberts — 6 Apr 2007 @ 10:20 AM

  56. Don’t know if this comment got through last time — I got a data access error, which seems to happen a lot with this site — so I’ll try again. Apologies if this is a double post.

    Sai Greisch, you left out a crucial component of nuclear bombs, the things that make it possible for them to explode when reactors do not. (Reactors do explode sometimes, but it’s usually a steam explosion, not a nuclear one.) Since this blog gets a lot of viewing, I won’t say what the missing component is, but the other physicists here will know what I mean.

    Comment by Barton Paul Levenson — 6 Apr 2007 @ 11:24 AM

  57. [[most people think nuclear power is dangerous. They have never heard of background radiation. They don't know that ancient mummies are dated by radioactive carbon.]]

    I think nuclear power is dangerous, and I know about background radiation (about 120 millirads per year in most places, isn’t it?), and I even know about carbon-14 dating. I’m going on the fact that there have been a couple of dozen nuclear reactors accidents with fatalities involved, and, more importantly, the fact that a really big accident could kill a really big number of people.

    Comment by Barton Paul Levenson — 6 Apr 2007 @ 11:27 AM

  58. [[How do I learn? Where do I start? Between job, family and my shocking lack of education, going back to school isn't really a possibility, I think. But what books did you lot chew through in school? Which do you throw at your students?]]

    Isaac Asimov’s collections of short essays were very valuable to me. For specific sciences, try to find used copies of high school and college introductory textbooks. And study as much math as you possible can. You should at least have a good grasp of algebra and a little trigonometry to follow what’s in most textbooks. (To actually do professional scientific work you’ll usually need to add calculus, linear algebra, differential equations, vector analysis and vector calculus, and statistics, and for some fields, especially physics, tensor and spinor calculus. No, I don’t know all that stuff either. :) )

    Comment by Barton Paul Levenson — 6 Apr 2007 @ 11:32 AM

  59. Eli, you make a good point. In one of my novels, where a teenage alien girl is hosting a teenage Earth girl for a year (alien year, different length), host girl, Throsu, is studying astronomy and recites a list of so many satellites of each of her system’s planets. Earth girl, Joanna, replies that Earth scientists have surveyed the outer system and report a much higher number of moons for the outer planets. Throsu replies, “The right answer is the answer the teacher wants to hear.”

    Comment by Barton Paul Levenson — 6 Apr 2007 @ 11:40 AM

  60. Kaoten: visit a local Community College or University and go to their bookstore. Freshman texts on subjects you like will help. At my Community College, there are also reference librarians who can help you find books, and even better, may also help you put together a reading list. Better still, enroll in a community college. As a former Professor at a local community college for 15 years, I had many students older than 30, some in their 50s coming back because their job was eliminated. Community colleges are also becoming more and more oriented to students like you, providing services and courses under an open admissions policy. At my college, about half the students were working full time, taking classes at night. And you can always audit a class.

    Good luck to you. I admire your spirit.

    Comment by Robert Bergen — 6 Apr 2007 @ 11:49 AM

  61. Re #52 (Eli) I’ve experienced test-gaming as a student and now as an educator, agree it’s a concern. An upside may be the development of critical thinking skills that become useful later in life as students go on to face others in positions of higher, or at least different power, e.g. bosses, politicians, judges, lawyers, and maybe even in everyday situations like dealing with folks in sales and customer service.

    As a middle school teacher, I’ll take testing problems over some of the other educational/societal challenges I face daily in the classroom, e.g. inadequate parent support, student obsession with pop culture and entertainment electronics, and inappropriate funding to name a few. All of these issues, I think, contribute to present and probable future state of society with its concerning lack of intellect.

    Figen and RC, thanks – I enjoyed the commentary and quiz, scored 83% ‘correct’, but the grade doesn’t really matter. I learned some things (from the response comments as well), and at a very reasonable cost!

    Comment by Scott Vinson — 6 Apr 2007 @ 12:08 PM

  62. Re #57: [ have been a couple of dozen nuclear reactors accidents with fatalities involved...]

    Against how many fossil fuel and hydropower accidents with fatalities? Thousands?

    [...a really big accident could kill a really big number of people.]

    And really big fossil fuel & hydropower accidents could kill really big numbers of people, too. Have done, in fact, which is more than can be said of nuclear power.

    Comment by James — 6 Apr 2007 @ 12:27 PM

  63. About heat can’t travel through a vacuum… My apologies indeed. I stand corrected by your comments and I got help from Raypierre in putting together this response. I was thinking of the heat insulating properties of a thermos. But heat can indeed travel through space as infrared radiation. It’s just that the Sun is so hot (about 6000K for the photosphere), and that at those temperatures the infrared is a small proportion of the Solar output. Nonetheless, solar near-IR does reach the Earth and other planets in sufficient quantities that it needs to be taken into account in climate models, — and is.

    Comment by Figen Mekik — 6 Apr 2007 @ 12:29 PM

  64. RE “The greenhouse effect and global warming are the same thing” being a problem, I think we can overdo scientific correctness.

    Of course GW can be caused by other forcings, aside from GHGs (which the contrarians so love to point out). However, for the common layperson I think it is OK to interchange these terms, hopefully with the understanding that there is a natural greenhouse effect that makes life on earth possible, but that we are now in a human-enhanced greenhouse effect situation.

    If I recall, I first learned about GW from the media as “the greenhouse effect,” and this term has held for a long time for people who don’t pay much attention to the media. Now the avant-garde is on to “climate change” (doesn’t it always change and is change always bad, some ask). When I heard CC, I thought, they’re trying to water down this big problem.

    There is really no good term for the current situation. Words fail us. Global warming, yeah, less snow plowing in winter, or maybe we don’t have to go to the tropics for vacation, the tropics will come to us. Warming to warm our hearts & spirits. Warm & fuzzy feelings.

    And greenhouse effect has the lush feeling of greenhouses growing orchids — paradise in a glass enclosure.

    Then there’s “an inconvenient truth,” but to me it’s more like a “moral failing.” Science just can’t quite get at the whole of GW.

    Comment by Lynn Vincentnathan — 6 Apr 2007 @ 12:59 PM

  65. I tried to post this comment yesterday – thanks, Figen – your summary brought me back to my days of teaching Introduction to the Atmosphere for undergraduates and high school teachers! You’ve done a great job of putting words to common experiences. (I once had a student who emailed me a picture of an flushing toilet in Australia to help dispel the toilet flushing myth.)

    The quiz you posted reminds me of why I loathe giving T/F and multiple choice exams to students. The sad truth is that these ARE the types of exams (and test bank questions) that are used to test knowledge. What else can you do with a class of 200-300 students? What I appreciated about the quiz was the explanation line (if it is used).

    Comment by Karen Kohfeld — 6 Apr 2007 @ 1:33 PM

  66. Kaoten, almost forgot. Have you heard of the Open Courseware project at MIT. They are putting on line all of the course ware for most of the courses they teach there. Quality varies, but you can find some great resources. Check it out:

    Comment by Ray Ladbury — 6 Apr 2007 @ 1:53 PM

  67. James (and other pro-nuclear advocates),

    You need to face the fact that you have an uphill battle ahead of you to get nuclear power to be widely adopted in the United States. You’re correct that coal and hydoelectric plants have killed more people than nuclear. So what? Mentioning nuclear power causes a visceral reaction in many people (voters) which makes this an emotional issue, not an intellectual one. A single National Geographic Magazine article on the ghosttowns around Chernobyl is more persuasive than a whole binder of facts and statistics.

    The nuclear power industry has itself to blame for much of its poor public image. For example, it lobbied for caps on liability for damages, while at the same time promoting itself as a safe energy source. That’s pretty hypocritical in the opinion of many people. Or how about promoting itself as a cost effective power source while making the taxpayers pick up the tab for perpetual waste storage. If the nuclear power industry wants better acceptance, it needs to earn it. Removing the cap on liability (the reactors are safe, aren’t they?) and internalizing the lifecycle costs (from the first bucket of uranium ore on) would be a start. If they are not willing to do that they should quit whining. I, for one, will be too busy installing PV arrays to listen.

    Renewable Regards,

    Comment by Phillip Shaw — 6 Apr 2007 @ 2:17 PM

  68. Re # 42 Kaoten: I’ll put in a plug for ‘Reading the Mind of God,” by James Trefil ( Trefil (a physicist at George Mason Univ) is an oustanding writer of science for the general public. I’ve enjoyed several of his books (e.g., A Scientist at the Seashore). In “Reading the Mind of God,” he explains how astronomers and cosmologists study the origin of the universe and our solar system (while he examins the Principle of Universality).

    Another book I found very useful at shoring up my knowledge of physics is “Clouds in a Glass of Beer: Simple Experiments in Atmospheric Physics,” by Craig E. Bohren ( Bohren (a physicist who taught meteorology at Penn State) is still a bit skeptical of AGW, I think. Nevertheless, he does a very good job of explaining common atmospheric phenomena in this book.

    RE The topic of this thread: Another popular misconception (if not total ignorance) among college science majors is why high tides (in the ocean) occur simultaneously on opposite sides of the earth.

    Comment by Chuck Booth — 6 Apr 2007 @ 3:01 PM

  69. But heat can indeed travel through space as infrared radiation

    There’s nothing special about ‘infrared’ radiation in this respect. Heat can be transmitted as radiation with a thermal spectrum, which in some temperature ranges peaks in the infrared. In other temperature ranges, it peaks at longer or shorter wavelengths (microwaves, visible, X-rays, etc.)

    Comment by Paul Dietz — 6 Apr 2007 @ 3:33 PM

  70. We burn all that coal to make electricity because most people think nuclear power is dangerous.

    No, we do it because it is cheaper to burn the coal, because the cost of the CO2 emissions are not included. Utilities in the US are often required to use the lowest cost sources of power.

    Comment by Paul Dietz — 6 Apr 2007 @ 3:37 PM

  71. Re #42: Kaoten — If your interest is primarily climate, I strongly urge you to read

    W.F. Ruddiman
    Earth’s Climate: Past and Future
    W.H. Freeman, 2001

    This is a fine beginner’s book, IMO…

    Comment by David B. Benson — 6 Apr 2007 @ 3:39 PM

  72. Re #58 Isaac Asimov’s essays (Barton)

    While I am already familiar with most of the math subjects you mention, I am a fan of Asimov’s and would like to read more of his scientific work. Which essays are you referring to?

    Comment by Dick Veldkamp — 6 Apr 2007 @ 4:06 PM

  73. Re #58 Isaac’s Asimov’s scientific essays (Barton)

    Should have done my homework first. Complete list of all 450+ books with reviews to be found at:

    Comment by Dick Veldkamp — 6 Apr 2007 @ 4:35 PM

  74. Re #67: [You need to face the fact that you have an uphill battle ahead of you...]

    The same could – still can – be said about trying to convince the public of that AGW is a real problem. Or indeed, to challenge any of the myths that have been mentioned in this thread. Should we then just give up, and accept popular belief as reality?

    As to your arguments re liability and costs, I have no problem with any of that, just as long as all forms of energy generation are placed on an equal footing. The government foots the bill for the damages that accidents to hydroelectric dams might cause – why should nuclear be treated differently? Fossil fuel plants get to dump their waste into the atmosphere, leaving the public to deal with the problems and foot the bills. Why should nuclear have to meet a different standard, and then try to compete on costs?

    Comment by James — 6 Apr 2007 @ 4:55 PM

  75. In #57, Barton Paul Levenson wrote:

    “I think nuclear power is dangerous, and I know about background radiation (about 120 millirads per year in most places, isn’t it?), and I even know about carbon-14 dating. I’m going on the fact that there have been a couple of dozen nuclear reactors accidents with fatalities involved, and, more importantly, the fact that a really big accident could kill a really big number of people.”

    Like Ronald Reagan, it’s not so much the things that Levenson doesn’ know that are the problem, it’s the things he does know that aren’t so.

    Those interested can visit Wikipedia’s rather detailed description of background radiation, at, and its rather detailed listing of civilian nuclear power accidents, at, and its list of military nuclear accidents, at to discover reality.

    Reality is that average background radiation worldwide is on the order of 360 millirem. Reality is also that there have been two civilian nuclear reactor accidents with fatalities, the RA-2 criticality accident in Buenos Aires in 1983, which killed one reactor operator, and the Chernobyl accident, which Wikipedia says killed 50 plant staff and emergency responders and was responsible for 9 thyroid cancer deaths. An accident at the SL-1 military reactor in Idaho in 1961 killed three operators (there is some evidence that it was a murder-suicide).

    The two accident lists include a wide variety of other civilian and military accidents (mostly military), particularly US Air Force Broken Arrow incidents and a stunning array of Soviet navy nuclear submarine accidents.

    A sizeable (and highly variable) fraction of the background radiation is due to radon, part of the decay chain of uranium and thorium in the ground. Curiously, the importance of radon as a contributor to background radiation was first discovered when a nuclear plant worker in Eastern Pennsylvania (the Reading Prong of high-uranium concentration rocks and soil) set off a plant radiation monitor when he was arriving for work one morning. He lived in a house with particularly high radon levels.

    The “really big accident” that Levenson writes about is hypothetical, in the sense that it has never happened, but might some day. Its “really big” consequences are also hypothetical, with predictions depending on assertions about the relationship between radiation dose and cancer induction, extrapolated down to doses far lower than anything we have actual data for.

    As another writer noted, there have been “really big” accidents with “really big” consequences in the fossil fuel industry and associated with hydropower facilities: 225,000 dead in the 1975 failure of 63 dams in Henan province in China, 2000 dead downstream from Vaiont Dam in Italy, hundreds dead in each of at least a dozen gas/LPG/natural_gas explosions and fires around the world (see any World Almanac). These are not hypothetical, they have really happened and continue to happen, with a frequency of several per decade.

    Best regards.

    Comment by Jim Dukelow — 6 Apr 2007 @ 5:02 PM

  76. I am confused about the discussion about hurricanes and Coriolis force. You write, “from satellite images hurricanes look like they are rotating counter-clockwise. Really can’t argue with what the students are seeing for themselves.” And yet, it is true that hurricanes (in the northern hemisphere, which is where that word is used) do in fact rotate counter-clockwise. Why would you suggest that reality is different from what students see for themselves, if both point to the same direction of rotation?

    Comment by Hal — 6 Apr 2007 @ 5:05 PM

  77. Kaoten, as far as general education resouces, you may find this site useful,

    Comment by Tavita — 6 Apr 2007 @ 5:27 PM

  78. Now, if I could just learn to spell! That would be *resources.

    Comment by Tavita — 6 Apr 2007 @ 5:30 PM

  79. “The “really big accident” that Levenson writes about is hypothetical, in the sense that it has never happened, but might some day. Its “really big” consequences are also hypothetical, with predictions depending on assertions about the relationship between radiation dose and cancer induction, extrapolated down to doses far lower than anything we have actual data for.”

    Such an accident could provide valuable hard data to help assess the effects of future accidents. I’d personally prefer to do everything possible to keep this in the hypothetical realm, however.

    Comment by Roger Smith — 6 Apr 2007 @ 6:09 PM

  80. Some responses:
    Chuck Booth: Yes tides makes the top of my list also in the “difficult to explain and comprehend” category.

    Tavita (#19): Thanks for the paper. I downloaded it and am in the process of reading it. It is lengthy!! But I’m looking forward to it.

    Hal: The confusion lies in saying things rotate clockwise in the northern hemisphere without taking into account movement in the vertical direction. Subtropical gyres (major subtropical surface ocean currents) do rotate clockwise in the northern hemisphere when you look at the world from space. But this is because on a broad scale subtropical gyres are downwelling zones. So if in the subtropical northern hemisphere you were to take a picture of a hurricane from space, the rotartion would look counter-clockwise seemingly in defiance of the Coriolis effect. BUT in reality Coriolis tells us moving objects will be deflected to the RIGHT in the northern hemisphere within the frame of reference of their movement direction. Hurricanes are low pressure zones, so in essence air is moving up. So you would have to look at the hurricane from the land or sea surface and not from space to determine its direction of rotation. And if you looked up from the surface at the hurricane, it would be rotating clockwise (deflection to the right). Hope that makes sense.

    Paul Dietz: By heat I mean infrared (long wavelength) radiation. So we get all kinds of radiation from the sun, but what I understood from what Raypierre told me is that because the sun is so hot, most of the radiation it emits is in the shorter wavelength range, though it does emit infrared also. This is all within the context of “the ozone hole does not leak solar heat” idea which is the misconception under discussion in relation to this topic :)

    Comment by Figen Mekik — 6 Apr 2007 @ 6:12 PM

  81. Jim, one difference between advocacy and science is that to do science, you are responsible for fairly presenting all the information, while as an advocate you may honorably present only that most favorable to your desired result.

    Would you add this information to your file, if you’re representing what you know as being science?

    “Table 2 shows the change in reported cancer cases before and following the Chernobyl accident. The
    post-accident incidence per million rose by as much as a factor of 200 from pre-1986 levels with an
    apparent latent period as short as 4 to 5 years. Tronko et al. (1999) report 577 cases of thyroid cancer in
    Ukraine between 1986 and 1997. Buglova et al. (1996) report that the incidence in boys is 50% higher
    than in girls. Goldman (1997) predicts that the ultimate number of cases will reach between 3000 and
    6000. The normal incidence of child thyroid cancer is low, typically less than 0.5 cases per million.”


    “Before the 1986 accident, natural background radiation levels in Slavutych were 0.009 to
    0.012 mrem/h (78 to 105 mrem/yr). Measurements made by the Radioecology Department of the
    Chernobyl nuclear plant in 1999 show that approximately 14.8 mrem/yr could be attributed to accident-
    related contamination. Background radiation levels in the wooded areas surrounding Slavutych are on the
    order of 0.03 mrem/h. ”

    Original document here:

    Note the title at the top of page 1 is unrelated to this content, which begins at page 4.
    HTML here:

    It’s basically an optimistic report.

    Comment by Hank Roberts — 6 Apr 2007 @ 7:08 PM

  82. Re #42 Koeten:
    Another book you might want to read is “Great Ideas in Physics,” by Alan Lightman (McGraw Hill). Lightman, a physicist turned professor of humanities at MIT) discusses fundamental concepts of physics (first and second laws of thermodynamics, theory of relativity, and quantum mechanics) from a conceptual and historical point of view, keeping the mathematics to a bare minimum.

    By browsing in used book stores (esp. in a college town), you can find old textbooks on virtually any subject that interests you. However, the problem with reading an introductory college text on, say biology, is that it has so much information it can be overwhelming; that is where a formal course can be useful, as the instructor can help guide you through the most important topics. But, when it comes to science, perhaps more valuable than any book, or college course, is just observing the world around you: If you are not already doing so, go for walks outdoors, at different times of day, in the woods, along the beach, in the mountains, along a stream, and just observe nature; or set up a bird feeder in your back yard and start watching the birds that show up; plant a garden and start thinking about the lives of plants, and what is going on in the soil; spend a couple of hundred dollars on a decent telescope (or a good pair of binoculars) and start watching the night sky (and listening to the sounds of nocturnal animals, while you are at it). And ask questions about what you are seeing, and hearing. Then, start looking for answers… you’ll probably find that simple questions usually lead to more questions, and you’ll end up digging deeper and deeper into subjects you never thought about before. That is how scientists learn – they tend to be very curious, and ask a lot of questions. But, unlike most people, they need answers, and they get frustrated when they can’t find answers, or when they find answers that don’t seem to make sense. So, they start looking for answers on their own, and they often end up somewhere very different from where they thought they were headed. That is basically how the history of science progressed over several hundred years, and it is how the research careers of many, perhaps most, scientists progressed.

    While I agree with others that it is never too late to enroll in college, you don’t need a college degree, or even a college course, to be curious and to start finding answers to your questions on your own (esp. with the resources now available on the internet).

    Comment by Chuck Booth — 6 Apr 2007 @ 7:49 PM

  83. #76 Perhaps the point is that if you look at the hurricane from our side, looking up, instead of from the astronaut’s side, looking down, the (northern hemisphere) rotation is clockwise.

    A feel for the nature and scale of the Coriolis “force” can be had by considering a Foucault pendulum. The huge pendulum’s swing rotates slowly in our frame of reference because of the Coriolis effect. A moment’s thought will lead to the obvious conclusion that the effect is going to be far to slow and slight to influence a toilet flush or bath plug vortex…

    Comment by Glen Fergus — 6 Apr 2007 @ 8:16 PM

  84. First of all, thank you so much, all of you. Your encouragements, help and brilliant attitude is heartwarming and deeply appreciated.

    I’ll be spending the evening (and the rest of the weekend) examining the suggestions you’ve made so far, including trying to figure out how feasible it is to sign up for classes. Hopefully it’ll give me some idea of how to address my ignorance Monday, as I’ve already arranged to take the morning off.

    As I said, I’m enormously grateful for your support, but I think I need to make a couple of things clear, and I’d like to comment on a few of your suggestions as well.

    Obviously I’m looking to learn more than simply how the world I live in works. I want to know why. It’s the same curiosity that got me to start a business. I never had a problem understanding what my old bosses told me, but the why was rarely obvious to me. Now I understand, earn less, and my hair’s gone gray.

    The big difference between the two, from my perspective, is that I at least knew the trade, but don’t in this case. Obviously I’ve had to learn quite a few things no 8th grader can be expected to know, but I think I need to make it perfectly clear that it’s at most things that will be of incidental use in trying to understand how nature’s put together. So at the chance of sounding like a complete tosser, I think it’s best if you attempt to make your suggestions relevant to an 8th grader. Like I said, I’d like to understand why things work like they do, not just that ‘they do because they do’. If nothing else, it’d be awfully nice to be able to explain to the kid we’re having, why clouds don’t fall down.

    “Even scientists at the pinnacle of their careers with degrees from prestigious schools are confronted with their ghastly ignorance about something every day.” – Figen Mekik

    This may sound a bit selfindulgent, but I can’t shake the feeling the scales involved are different by an order of several magnitudes. It’s the ‘special knowledge’ versus ‘general knowledge’ thing, I think. But I’ll send you ignorant scientists/science nerds a kind thought when I chew my way through your suggested reading ;)

    “The first question I have for you is: What is it you want to learn? You will have much more success getting through the inevitable dry parts of any subject if you know you’ll be rewarded with understanding something that interests you down the road.” – Ray Ladbury.

    Everything? I don’t know that I need to learn anything about language, but I’m in no position to be sure. I absolutely need to learn a great deal of math. I’ve obviously had to learn some already, but far from enough. Especially since I rely heavily on software to do much of the work for me. Isn’t it curious how computers allow even a comparative savage to run a company?

    My interest is completely general. I know nothing of physics, chemistry, biology, geology or any other -ology. To be blunt, I don’t understand the world I’m part of, but I greatly desire to. I’m no mystic or anything, but the test made it perfectly clear to me that I simply don’t know anything at all, about anything. It’s clear to me that my entire worldview consists of vaguely formulated induction, and that’s simply not satisfactory to me. If nothing else, I want to at least be sure that my participation in the democratic process isn’t based in what can only be called superstition. I’m painfully aware that’s what it has been, so far.

    “Good luck and feel free to contact me offline as your program progresses.” – Ray Ladbury.

    Thank you very much. I just might do that.

    “Go back to school.” – Elizabeth.

    I’d like to, and hopefully I’ll have cleared up by Monday if it’s at all possible for me right now. Unfortunately I doubt it is, but fortunately I have quite a lot of experience in self study (I’ve taught myself this language, for example). So hopefully all’s not lost if classes aren’t an option.

    “visit a local Community College or University and go to their bookstore.” – Robert Bergen.

    I will, thank you. I don’t consider my age an obstacle (I’m only 30), I just don’t have a lot of maneuvering room in my schedule.

    “Have you heard of the Open Courseware project at MIT.” – Ray Ladbury.

    It would be fantastic if some decent teachers with enough spare time, got together and organised some real online education. Hopefully it’ll happen soon, but in the mean time; if you have the resources to try something like that, do give it a shot. I’ve spoken to a number of the people I associate with since my last post, and while I’m alone in my desire to seriously educate myself, I know at least 12 people who’d jump at a chance to learn a bit of maths, physics and biology if there was an easy way to get started.

    “No theory of everything jazz, just the basics like classical mechanics and thermodynamics and the like that affect things most people come in contact with.” – Bruce.

    Thanks a lot. String theory and the like is all very amusing, but you’re completely right that it’s not what I’m asking. I’d need a PhD. in physics to understand it, and though I’ll not rule out I might want one some day, some basic maths and chemistry is more relevant just now.

    Again, thank you all. You have been incredibly kind and helpful, and please don’t stop if you have further suggestions. I’ll be checking back regularly and try to find out what to buy, who to talk to and what to talk to them about. And I am deeply humbled by your eagerness to get me on the right track. I hope I’ll be able to return the favour to someone, some day.

    Have a great weekend all of you. Regards, Kaoten.

    Comment by Kaoten — 6 Apr 2007 @ 8:43 PM

  85. As an educated “layman,” my question for Ray Ladbury, comment 29, who said:

    “Ironically, this fear can be even greater if the “layman” is educated in some specialized discipline, but not, say, in climate. In this case, much of the ego of the layman may be tied up in considering himself intelligent–and not to tell him he doesn’t understand something may be considered an affront. I think it was Mark Twain who said, “What gets us into trouble is not what we don’t know. It’s what we know for sure that just ain’t so.”

    (a) Why do you exempt “climatologists” from Twain’s aphorism? Why should “laymen” presume they “know” anything about what is causing short term warming when they can’t explain warming or cooling in any of the periods in the earth’s long past. Who’s thinking scientifically now?
    (b) Why do you paraphrase Twain, then place it in quotations as if this is precisely what he said? Isn’t that a misrepresentation and potentially misleading?
    (c) Good analogy to information asymmetry, “IA,” however, and why people might reject what they intuitively know they don’t understand. Since economics is really just the study of human action and, therefore, one of those “useless” social sciences, it unfortunately doesn’t appear to have gotten the currency it deserves here. The warmists and climatologists ought to have a little more understanding about “IA” and, then, maybe they’d have a bit more honesty about revealing what they don’t know or understand.

    Comment by BillOGoods — 6 Apr 2007 @ 9:30 PM

  86. Re # 85 BillOGoods:
    You seem to have a fundamental misunderstanding of science and scientists. Scientists confront their ignorance every day – that is why they do research, to find answers to that which they do not know. There is no question that some scientists are arrogant in thinking that they know more than they do about a particular topic, and they often get rebuked by other scientists (and non-scientists) for that arrogance -unfortunately, that is simply human nature, esp. with people who make a living by learning vast amounts of information. I’m quite sure there is not a significant field of human inquiry that isn’t full of unanswered questions. But, just because scientists (or economists, or historians) don’t know everything, doesn’t mean they know nothing. If you read the posts by the RealClimate scientists at this site – not the comments, most of which are by non-climatologists- you will see that they readily admit what they do, and don’t know. For you to suggest that “they can’t explain warming or cooling in any of the periods in the earth’s long past” is, well, a sign of your ignorance of climate science.

    Comment by Chuck Booth — 6 Apr 2007 @ 10:27 PM

  87. Re #75: [The "really big accident" that Levenson writes about is hypothetical, in the sense that it has never happened, but might some day.]

    I think it can be argued that Chernobyl was that “really big accident”: that it was pretty close to being as bad as a reactor accident could possibly be. A large chunk of the core melted down, and (since there was no containment at all) was dispersed about the landscape by the graphite fire. And the effects on the public were magnified by Soviet-era policies of concealment & disinformation.

    Comment by James — 6 Apr 2007 @ 10:41 PM

  88. Kaoten, age is irrelevant. I had to go back to school a first time at 28 and a second time at 35 for complete career changes. I had the advantage of having a rather solid fundation in science from my high school days, which definitely made things easier, but motivation was the key. I went to a community college where I had to do a number of basic courses before starting the specialized practical stuff, and I loved it. Sometimes I used to just deambulate in the library and look at books by subject matter, dreaming that I could have the time to learn at least basics in every one of them!

    If there is one practical tip I can give you, it would be this one: take some math courses and don’t let go of any subject in those before you are comfortable with it. In high school, I studied biology, chemistry, physics, and maths. Of all these, maths is an outstanding way to learn intellectual rigor, good reasoning, even logics. It shapes the mind in a way that enables you to tackle any other scientific subject, and many non scientific ones. Even though I did not perform very well in maths in high school (I was too lazy to do the necessary homework!), what little was left of it years later was still invaluable. I am looking forward to learning more as soon as life circumstances will allow.

    Comment by Philippe Chantreau — 6 Apr 2007 @ 11:15 PM

  89. On the Coriolis force: I learned back of the envolope forcasting of wind direction (from yacht racing) with the rule: in the northen hemisphere wind flows from high pressure to low pressure with a twist to the right. In most cases this works on the short term in normal conditions. For hurricanes (with an intense low pressure center) should rotate counter clockwise since from any point on the outside of the low pressure center the wind flowing in would be deflected to the right (when looked at from above). What am I missing here?

    Comment by John Sully — 6 Apr 2007 @ 11:35 PM

  90. See:
    The average coal-fired power plant puts as much radiation into the environment as the Chernobyl accident did, but over a period of about 7 years. The difference is that nobody measures the radiation from the coal-fired power plant.
    At least 73 elements found in coal-fired plant emissions are distributed in millions of pounds of stack emissions each year. They include:
    Aluminum Chromium Molybdenum
    Antimony Cobalt Nickel
    Arsenic Copper Selenium
    Barium Fluorine Silver
    Beryllium Iron Sulfur
    Boron Lead Titanium Thorium
    Cadmium Magnesium Uranium
    Calcium Manganese Vanadium
    Chlorine Mercury Zinc
    Chinese industrial grade coal is sometimes stolen by peasants for cooking. The result is that the whole family dies of arsenic poisoning because Chinese industrial grade coal contains large amounts of arsenic. Coal from Perry, Illinois contains up to 103 parts per million of uranium.

    Comment by Edward Greisch — 7 Apr 2007 @ 12:40 AM

  91. Figen, I have read your post and comments about the Coriolis effect and I cant understand what you are trying to say. Post 89 is correct. The wind rotate counter clock wise around a low pressure system (as a hurricane) and clockwise around a high pressure system (seen from above but in the reference earth reference fram). Why should the vertical motion matter when it is very slow compared to the horizontal motion? I might start to understand what you are trying to say but your use of reference frames is confusing.

    Comment by Fredrik — 7 Apr 2007 @ 6:30 AM

  92. All of this just goes to show why Governments and hence nations rely on a small number of experts (2500 in the IPCC’s case) to give us the diagnosis that the Earth is becomming a little ill. The reason why everyone is so up in arms about its findings and reticence is rife is simply because humanity is not that strategic in nature. No one can currently see past the fossil fuels that we currently use and vested interests are so deeply entrenched and fortunes made and lost in this arean that I sincerely doubt that 2 deg C tempeature rise will be avoided before we move to something else if that something else exists at all.

    Comment by pete best — 7 Apr 2007 @ 6:36 AM

  93. Re 85: BillOGoods, I don’t know if you’re just a post ‘n run skeptic or whether you’ll check for replies, but here goes. First, climate scientists are not immune to the foibles of humanity, but one is more likely to err the further one strays from ones field of expertise. We see this in climatologists when they stray into fields like economics. In order to understand climate, one must have at least a reasonable understanding of meteorology, so a climatologist is probably less likely to say something astoundingly stupid about meteorology.
    Second, it is not arrogance to insist that one know what one in fact knows. Climate science is actually a fairly mature science. We understand the drivers of climate and mostly how they interact. We can predict the effects of perturbations, such as the Pinatubo eruption. To contend that we do not understand past climate is a mischaracterization. The further one goes back the more difficult it becomes to reconstruct all the factors, but at least in broad outline, we understand Earth’s climate history going back hundreds of millions of years. Do we expect economists to understand everything about the economic forces that gave rise to feudalism in Medieval Europe? Yet we feel we understand the period sufficiently well to see how it fits into European history as a whole. I’m sure I’ll be accused of becoming Helen Quinn’s biggest fan, but I again suggest reading her essay from the January Physics Today:
    BTW, the Twain quote is as close as I can reconstruct it, and I have seen this version many times. Twain, however, had a tendency to paraphrase himself, and reuse many of his best lines over and over. Therefore, I consider any quote attributed to him both a quote and a paraphrase.
    I for one do recognise the value of economists in this debate. However, in concert with the admonition of Mr. Clemens, would it not be more reasonable for economists to ensure that remedial action on climate change is economically sound rather than trying to discredit the science in which they are not expert. There are plenty of climate experts looking over each others’ shoulders for the slightest flaw in their rivals’ research. If they find such a flaw–particularly one that implies a revolutionary change in our outlook on the climate–it is strongly in their interest to publicize that flaw and enhance their own reputation.
    Again, as Chuck said, climate scientists are very clear about what they do and do not know. This clarity is sometimes obscured in media reports (usually erring on the side of the science being more uncertain or the consequences more sensational). In this, climate science is not unique, but the high profile of the subject draws more attention to such media distortions.

    Comment by Ray Ladbury — 7 Apr 2007 @ 7:30 AM

  94. Hello John Sully and Fredrik,

    Sorry my wording was confusing, but we are saying the same thing. Of course winds rotate counter-clockwise (in the northern hemisphere) in low pressure systems (which is what I said-or tried to say). But the confusion students have is if everything is deflected to the right in the northern hemisphere, how come subtropical ocean gyres rotate clockwise and hurricanes rotate counter-clockwise (opposite directions)? To explain what looks like opposite I tried to say we are looking from space and not within the frame of reference of the moving object. That’s my point. So there is no directional paradox, everything is deflected to the right in the northern hemisphere, whether it is ocean or air. But, when looking at Earth from space (like a thought experiment if you will) in high pressure (air) or downwelling (ocean) zones the rotation appears clockwise, and in upwelling (ocean) or low pressure zones (air) rotation appears counterclockwise in the northern hemisphere. Subpolar ocean gyre rotate counterclockwise (in the northern hemisphere) for the same reason.

    Comment by Figen Mekik — 7 Apr 2007 @ 7:43 AM

  95. I just posted a reply to John and Fredrik that will be up soon, in case this goes up before that. But maybe I should have said perpective instaed of frame of reference, though perspective implies a subjectivity which may make it more confusing. Anyway, Glen Fergus (#83) has a more eloquent explanation.

    Comment by Figen Mekik — 7 Apr 2007 @ 8:12 AM

  96. Kaoten -
    Here’s a link to MIT’s OpenCourseWare site:
    A large number of courses have at least some content on line; some have quite a bit, up to and including video of lectures.

    Here’s a page with Real Media video of a complete set of lectures for 8.01, MIT’s first semester physics class (Physics I: Classical Mechanics):

    Comment by David Warkentin — 7 Apr 2007 @ 8:41 AM

  97. [[While I am already familiar with most of the math subjects you mention, I am a fan of Asimov's and would like to read more of his scientific work. Which essays are you referring to? ]]

    For decades Asimov wrote a monthly column for the Magazine of Fantasy and Science Fiction (“F&SF” in the trade) where he could talk about anything he wanted to. Most of the essays were about science, and they were collected in books in groups of seventeen. Some titles I remember offhand are The Tragedy of the Moon; Opus 100; Opus 200; The Sun Shines Bright; Quasar, Quasar, Shining Bright, etc. There are also recent expensive hardbacks with collections of 100 essays at a time (The Tyrannosaurus Prescription is available through Amazon), and a web site has a number of them available for free:

    Note that the early ones will have details or sometimes even concepts wrong, reflecting the times when they were written (roughly 1962-1992), but they often clue you in to general principles in a very useful way, and later ones sometimes correct or re-evaluate earlier ones.

    Essay collections by Carl Sagan (Broca’s Brain, The Cosmic Connection, etc.) are very good for astronomy, and those of Stephen Jay Gould (Hen’s Teeth and Horse’s Toes, The Panda’s Thumb, etc.) are great for evolutionary biology, with occasional forays (like Asimov, and Sagan) into other subjects.

    Comment by Barton Paul Levenson — 7 Apr 2007 @ 8:50 AM

  98. [[Reality is also that there have been two civilian nuclear reactor accidents with fatalities]]

    No, that’s not reality, that’s industry spin. Partly it depends on how they disingenuously define “civilian” deaths. There were fatalities twice at a Virginia reactor, at a Russian reactor, at a Czech reactor, in fueling operations happening back to the Manhattan Project, and several times in Soviet nuclear sub reactor accidents (not “civilian,” like the American SL-1 accident, which, incidentally, may have been the first case of deliberate nuclear sabotage, a problem which remains). I’m getting a list together which I’ll post publicly when I have the time.

    Again, the danger is of a big accident, which Dukelow very rightly notes hasn’t happened yet. Of course, there isn’t much of a worldwide nuclear industry yet, except possibly in France. What are there, 200 nuclear power plants worldwide? Or 500?

    There are also the problems involved with storing the wastes, and with the opportunities for terrorists when large amounts of nuclear materials are moving around the country. There have been many incidents where soldiers sold or stole weaponry, even advanced weaponry, from US military bases. Are reactor operators less corruptible?

    Comment by Barton Paul Levenson — 7 Apr 2007 @ 8:58 AM

  99. Figen, I still dont understand what you try to say.

    “To explain what looks like opposite I tried to say we are looking from space and not within the frame of reference of the moving object. That’s my point. So there is no directional paradox, everything is deflected to the right in the northern hemisphere, whether it is ocean or air.”

    I belive you haven’t understood the forces involved. Everything should be measured against the earth.

    Different forces act on the air (wind) and water in the oceans. First the air. A parcel of air feels a force in the direction of the center of a low pressure system. It wants to move in that direction but get deflacted to the right by the corolis force. After a while is the corolis force and the force from the low pressure system equal in size and of opposite direction. Thus the air is moving counter clock wise around the lowpressure system. No different perspective or anyting.

    The gyres seems to be equalent to a high pressure system. Thus the difference in rotation.

    The corolis force only acts on objects that is moving and the properties on the force that make the movement determine the direction of rotation. An airplane with a force in the moving direction is going to make a large slow clockwise circle. A particle in a attracting radial (correct name?) force field is going to rotate counterclock wise around the center and a particle in a reppelling radial force field is going to rotate clockwise around the center.

    Comment by Fredrik — 7 Apr 2007 @ 9:08 AM

  100. I did a misstake in my post above. The lowpressure force and the coriolis force is not going to be equal.

    Comment by Fredrik — 7 Apr 2007 @ 9:24 AM

  101. Barton Paul Levenson wrote: “Of course, there isn’t much of a worldwide nuclear industry yet, except possibly in France. What are there, 200 nuclear power plants worldwide? Or 500?”

    FYI, the Nuclear Energy Institute, the lobbying group for the nuclear power industry, has an April 2nd press release about a new study by Cambridge Energy Research Associates (CERA) entitled Is the �Nuclear Renaissance� Real?.

    The press release has a helpfully concise summary of the current state of the nuclear power industry:

    The CERA analysis finds that the global political, environmental, economic and business situation is favorable for expansion beyond the current base of 435 nuclear power reactors, which together provide 369 gigawatts (GW) of electricity generating capacity and 16% of total worldwide electricity generation. Twenty-eight additional units with 23 GW of capacity are currently under construction worldwide; 20 countries now have new plants either under construction or under development, with well over half of new nuclear plants likely to be built over the next two decades in five countries — China, India, Japan, South Korea and the United States. In the U.S., several dozen reactors are in various stages of proposal development; international nuclear vendors and service providers are forming new alliances; and rising uranium prices have led to development of new mines.

    As the first sentence of that paragraph suggests, the CERA study has a relatively optimistic view of the prospects for a “nuclear renaissance”, balanced by recognition of factors that could limit or slow nuclear’s growth, and the press release is useful reading for anyone who wants to get a sense of the nuclear industry’s plans for growth in the 21st century.

    If course, while the report does discuss the competitiveness of nuclear with coal and natural gas fueled electrical generation, the press release makes no mention of wind or photovoltaics (both of which are growing worldwide by 30 to 40 percent per year) and falsely asserts “there are few effective options for carbon-free electricity production.”

    The press release also notes that “supportive government policy is essential for nuclear development”, in particular “a predictable structure for power markets”.

    But power markets are on the threshhold of dramatic transformation with the advent of low-cost distributed rooftop photovoltaics, wind turbines, distributed electrical storage technologies and a new generation smart grid (e.g. Al Gore’s “Electranet”) designed to intelligently integrate diverse power sources distributed and centralized, large-scale and small scale, baseline and intermittent — with an equally diverse population of electricity consumers, many of whom will themselves be producing and storing their own electricity. These new technologies and the power markets that evolve with them will be as disruptive to large centralized electrical generation, including nuclear power, as the PC was disruptive to mainframes, as the VCR was disruptive to the film industry, as cell phones were disruptive to the telephone industry, as the Internet has been disruptive to TV news and newspapers.

    What we need is government policies that open up the grid and power markets to the participation of diverse, distributed small-scale renewable energy producers, and government policies (again citing Al Gore, policies like the DARPAnet project that developed the original Internet) to develop the technologies needed to implement the intelligent distributed “Electranet” of the 21st century — NOT government policies that enforce and protect “a predictable structure for power markets” that is predictably favorable to and profitable for the wealthy, powerful entrenched corporate owners of large-scale, centralized electricity generation.

    Comment by SecularAnimist — 7 Apr 2007 @ 9:59 AM

  102. Re: Asimov

    My favorite of Asimov’s essay collections is “Science, Numbers, and I.” I learned a lot of science in my youth from Asimov; most of what I know about organic chemistry I learned from “The Genetic Code.” These, days, it’s terribly out-of-date, but the first half of the book is an introduction to enough organic chemistry to understand the structure of DNA, and that part is so well written, it’s still an extremely valuable resource.

    Taking him all in all, I shall not look upon his like again.

    Comment by tamino — 7 Apr 2007 @ 10:09 AM

  103. What gets us into trouble is not what we don’t know. It’s what we’re so sure of that we don’t check the references.

    Comment by Hank Roberts — 7 Apr 2007 @ 10:36 AM

  104. Re #98: [Partly it depends on how they disingenuously define "civilian" deaths.]

    Define them however you like, the plain and simple fact is that there have been far fewer deaths from nuclear plant accidents than from any other mainstream form of power generation – and that’s not even getting into the number of secondary deaths from air pollution, or those that will be caused by AGW.

    [There are also the problems involved with storing the wastes...]

    On the one hand, you’ve got the problem of storing a few truckloads of solid “wastes” from a nuclear plant (most of which could be reprocessed and reused), versus the problem of capturing and storing millions of tons of fossil-fuel waste, most of which is a gas. Which is easier to solve?

    Even if we accept the claims of the anti-nuclear people, that nuclear waste would have to be stored for 50K years or so – well, it seems to me that CO2 storage has to be forever. Or at least have such a low leakage rate that biolgical & geological mechanisms could convert it to carbonate rocks. Hundreds of millions of years, at a guess?

    [...and with the opportunities for terrorists...]

    This unavoidably gets into politics, but I’ll try steer as clear of the morass as possible. We see the likes of North Korea, Iran, and Pakistan building nuclear weapons with no real intervention by the rest of the world. “Terrorists” already have nuclear weapons, which makes this nothing more than a straw man argument.

    Even supposing that “terrorists” could steal nuclear material from a reactor, the harm that they could cause with it would still be less than that caused by fossil-fuel emissions.

    Comment by James — 7 Apr 2007 @ 11:10 AM

  105. Kaoten,
    For lots of subjects try: lots of their courses are excellent

    Comment by Chris — 7 Apr 2007 @ 4:40 PM

  106. So, How many of us wrote to the quiz makers to complain? A kid could take that quiz and unlearn the good science that we had so carefully taught them.

    How will the test makers know that there is a problem with the quiz if we do not tell them? I did, but they are not going to listen to just one malcontent.

    Comment by Aaron Lewis — 7 Apr 2007 @ 5:45 PM

  107. I thought about complaining too, but it needs to come en masse as you say Aaron Lewis. Otherwise it is just the complaints of someone who didn’t do as well as she hoped to.

    Comment by Figen Mekik — 7 Apr 2007 @ 5:47 PM

  108. Speaking of “A Private Universe”, you really should go look at the Annenberg CPB program “Minds of Our Own” that you may sometimes see on your PBS stations. They gave MIT graduating engineering students a flashlight bulb, a battery, and a piece of wire, and a surprising number of them couldn’t figure out how to make the light bulb light up! A lot of them burned their fingers by shorting the battery with the wire without ever getting the bulb in the circuit! Then they gave Harvard graduating students a stick of tree wood and ask them where the carbon in the wood came from, and most of them didn’t know the answer. They coyly mentioned photosynthesis, and it still didn’t ring a bell with the Harvard graduates. Ever hear of carbon-dioxide in the atmosphere and photosynthesis? YUP! That is where EVERY BIT of the carbon in all the wood that has ever existed came from. Carbon-dioxide is NOT a pollutant, it’s plant food!! Without it, every green plant in the world would die.

    Comment by Kurt Greske — 7 Apr 2007 @ 7:38 PM

  109. While growing up my favorite reads were pretty much all of Asimov’s work, all of Arthur C. Clark’s work (not just 2001 a Space Odyssey, but even The Deep Range), Zen and the Art of Motorcycle Maintenance, The Dancing Wu Li Masters, Teachings of Don Juan (all of Carlos Castenada’s books), and of course the entire series of the Hitchhiker’s Guide to the Galaxy (a trilogy in five books).

    Comment by Figen Mekik — 7 Apr 2007 @ 7:42 PM

  110. RE #108 “Carbon-dioxide is NOT a pollutant”

    Tell that to the relatives of the 1700 people who died in Camaroon in 1986 when a cloud of CO2 erupted from Lake Nyos (Science, April 10, 1987, Vol. 236. no. 4798, pp. 169 -175;

    I’m always amazed when I see or hear people say that CO2 is not a pollutant because it is “plant food.” Water, oxygen, and NaCl are all essential to life, yet each of these can be toxic if consumed in excess. And too much CO2 can be unhealthy for plants. With the possible exception of water vapor, any chemical released from a smoke stack, exhaust pipe, or industrial process that accumulates in the environment and is potentially dangerous to living organisms can be reasonably considered a pollutant.

    Comment by Chuck Booth — 7 Apr 2007 @ 8:29 PM

  111. Re: 108

    Kurt Greske says, “Carbon-dioxide is NOT a pollutant, it’s plant food!! Without it, every green plant in the world would die.”

    If too much “plant food” in the atmosphere and ocean, through its effects, causes harm to humans and other species then I consider it to be a pollutant and it should be reduced to levels that cause no harm, but keeps plants green.

    Comment by Tavita — 7 Apr 2007 @ 8:55 PM

  112. Thanks for your comments, all, particularly 93 and 86. A few of my own:
    First, correct, I haven’t read everything on this site, but, I dare say, neither have you. I am confident that any honest climate historian will have more unanswered than answered questions about why the earth’s temperatures have changed in the past. Yet, all the physical data that preceded, existed during, and existed subsequent is there for him to see. With that being the case, I find it arrogant to conclude the catastrophes and calamity that is being discussed. Even more arrogant is the degree of certainty that warmists say doing “X,” i.e., stop using coal fired power plants, gasoline powered cars, and the like, will produce “Y,” i.e., lower temperatures. What’s the proof of that? None.

    Second, surely the farther away from one’s expertise you roam, the more likely you will err. So, how far away from climatology is astronomy, heliophysics, and solar physics? Respected scientists in these areas of study seem to disagree with the idea that CO2 trapping heat is the answer. See
    Yet, with all hear from opposing climatologists when they are confronted are lame answers like “he’s not a climatologist.”

    Third, so, Ray, economists should just bend over and start “realizing” that “remedial action” on climate change is “economically sound.” You’re kidding right? If you are wrong that there is warming that man can or should do anything about, then there is principle of economics called “opportunity costs.” Think of the billions of dollars that could be put to a far better and more productive use than wasted on a fool’s errand.

    I think it’s tragic you give lip service to having open minds as scientists and you all act like lemmings behind the politicians that you claim distort your science.

    I’ll be back, but right now, I gotta watch a hockey game (MSU v BC for the NCAA Championship)

    Comment by BillOGoods — 7 Apr 2007 @ 9:37 PM

  113. Re #108: [Carbon-dioxide is NOT a pollutant, it's plant food!! Without it, every green plant in the world would die.]

    It’s both, both in practice and by legal definitions of what constitutes a pollutant. Consider phosphorus: an essential plant nutrient in small quantities, yet a pollutant when there’s too much in the wrong place.

    Like so much else in this world, it’s not good or bad in itself. Take water: without it, every human in the world would die, yet we still worry about floods and drowning. Indeed, simply drinking too much water can kill you.

    Or for a closer parallel, consider that without oxygen all the higher animals would die. Yet if we somehow managed to double the oxygen content of the air, most plant life would soon be consumed by uncontrollable firestorms.

    Comment by James — 7 Apr 2007 @ 9:47 PM

  114. Re #98, BArton Paul Levenson wrote:

    “[[Reality is also that there have been two civilian nuclear reactor accidents with fatalities]]

    No, that’s not reality, that’s industry spin. Partly it depends on how they disingenuously define “civilian” deaths. There were fatalities twice at a Virginia reactor, at a Russian reactor, at a Czech reactor, in fueling operations happening back to the Manhattan Project, and several times in Soviet nuclear sub reactor accidents (not “civilian,” like the American SL-1 accident, which, incidentally, may have been the first case of deliberate nuclear sabotage, a problem which remains). I’m getting a list together which I’ll post publicly when I have the time.

    Again, the danger is of a big accident, which Dukelow very rightly notes hasn’t happened yet. Of course, there isn’t much of a worldwide nuclear industry yet, except possibly in France. What are there, 200 nuclear power plants worldwide? Or 500?

    There are also the problems involved with storing the wastes, and with the opportunities for terrorists when large amounts of nuclear materials are moving around the country. There have been many incidents where soldiers sold or stole weaponry, even advanced weaponry, from US military bases. Are reactor operators less corruptible?”

    Levenson insists on offering a few more things he knows that aren’t so — and one that is so. The one that is so: An experimental Czechoslovak reactor A-1 at Bohunice (now part of Slovakia), suffered a 1976 leak of its carbon dioxide coolant that killed two plant workers. The heavy-water-moderated, natural-uranium-fueled reactor was cooled by high pressure, high temperature carbon dioxide. There are two likely mechanisms for the accident. A pinhole leak of high temperature, high pressure carbon dioxide would be an invisible high velocity jet. Plant workers walking into the jet could be badly burned and lacerated. The other mechanism would be accumulation of heavier than air carbon dioxide in low parts of the plant causing asphyxiation. In 1977, Bohunice A-1 suffered a serious fuel loading accident, that apparently didn’t kill any workers, but did eventually lead to the decision to decommission the reactor.

    The 1976 A-1 accident does not appear on the Wikipedia list I cited. Almost all Internet references to it appear to be copied from a Greenpeace list of nuclear “incidents” that I considered to be suspect because it contained so many identifiable errors and imprecise uses of language. However, I found independent confirmation of it in a 2 September 1980 NYTimes article and in a paper presented at the 2002 Waste Management conference in Tucson. I’ll note parenthetically, that, in the past, I have found reports by Greenpeace International’s Josh Handler and by the Norwegian environmental group Bellona to be the best sources of detailed information about the performance (or, rather, lack of it) of the Soviet nuclear establishment.

    Levenson apparently refers to an accident at the Surry reactor in Virginia that killed three or four workers. A pinhole steam leak on the secondary side of the Surry plant (the steam turbine, electrical generator side of the plant) burned and lacerated the workers when they inadvertently walked into the steam jet. That sort of narrow jet of high temperature, high pressure steam will go for many feet before it begins to condense and becomes visible. This sort of accident could happen in any facility — fossil-fuel electrical plant, refinery, chemical plant, steamship, etc. — that uses high pressure, high temperature steam to turn heat energy into mechanical work. The interested can review some of the 145,000 hits that a Google search on “steam leak fatality” produces.

    The reference to a Russian reactor (as vague as most of what Levenson writes on this topic) probably refers to a 2005 accident on the grounds of the Leningrad Nuclear Plant at Sosnovy Bor that killed a worker. The only problem with the reference is that the accident occurred at a smelter located on the grounds of the nuclear plant, not at the reactor.

    If Levenson actually bothered to do some fact-checking, he would have discovered that SL-1 was an experimental Navy reactor, military, not civilian.

    There are about 450 commercial nuclear power reactors world-wide, not 200. 58 of those reactors are in France.

    As James notes in Post #87, you could reasonably argue that Chernobyl was the “really big” nuclear plant accident, in terms of the fraction of core contents released to the environment. What it didn’t have were “really big” consequences, at least not by the standards of the fossil-fuel industry and hydropower.

    Outside the Soviet bloc, there have been no public health and safety issues with nuclear wastes. Most spent fuel is currently stored at the nuclear plant sites, so transportation of spent fuel has not been much of an issue so far. The casks in which fresh fuel and spent fuel would move on highways and the rail system have been analyzed for a variety of attack scenarios. The corruptibility of nuclear plant operators is certainly open to question and both attack scenarios and sabotage scenarios have included the assumption of insider involvement. The radioactive material in a plant that might be of interest to terrorists is essentially impossible to steal because of the high radioactivity levels and need for heavy shielding, if it is to be moved.

    Finally, industry spin or not, Chernobyl (civilian) and Mayak (military) are the only nuclear industry accidents that have produced civilian, as opposed to worker, deaths. Again, quite in contrast to the fossil-fuel and hydropower industries.

    Given Levenson’s aversion to citations for sources for his assertions and his obvious lack of knowledge of the topic, his list ought to be interesting.

    Best regards.

    Comment by Jim Dukelow — 8 Apr 2007 @ 12:01 AM

  115. Kurt Greske: obviously, it’s both. Pretending otherwise is rhetoric.
    If you’re here sincerely, just repeating what you believe because someone told you was true, this is a good place to learn honest skepticism. First, check what you were told. You can look this stuff up for yourself, and make up your own mind to learn. Any good librarian can help you out.

    Or try a few of the terms you’re familiar with in Google Scholar. These may be helpful to start with:

    Comment by Hank Roberts — 8 Apr 2007 @ 12:35 AM

  116. Re: 109

    Go type “climate change” into Wikipedia and read what comes back.

    Specifically, look at the graph of “phanerozoic carbon dioxide” in the atmosphere over the last 500 million years ( if you click on the graph in that article you will get an enlarged version that is easier to read ) and note where the carbon dioxide level is NOW compared to where it was in prehistoric times.

    Could it get much lower than it is now? Note how much higher it has been in the past when man didn’t exist at all.

    Comment by Kurt Greske — 8 Apr 2007 @ 2:52 AM

  117. Aaron

    RE your #106 post. Like you I did the quiz and noticed just how weakly constructed the questions are. A suspicious person might think that the real purpose of the quiz is to extract pedantic answers from knowledgeable folk. In this light it succeeds beautifully.

    Doudoo Doudoo Doudoo…

    Comment by Philip Mulholland — 8 Apr 2007 @ 3:10 AM

  118. Sorry guys I couldn’t keep up with the blog that I love most for the past several days. Been spending too much time shoveling this April snow out of my driveway. Sister down in Louisiana tells me it’s gonna be a 38 degree Easter Sunday there.

    OK, so any important events on the warming disaster about to befall us while I was away?

    Comment by BJandTheBear — 8 Apr 2007 @ 4:19 AM

  119. Re: 110

    I don’t think CO2 levels 500 million years ago really have much to do with us. As you correctly point out, humans did not exist (or evolve) with anything close to those levels (archaic Homo Sapiens only appeared around 400,000 years ago and modern humans have only been around for about 170,000 years). I think what the levels have been throughout Homo Sapien’s existence are more relevant to what we and our fellow species are used to and can tolerate; CO2 levels have been between 180-300 ppm for about the last 650,000 years. In other words, the current levels at 380 ppm are unprecedented in our entire history as a species; we are heading into uncharted territory for us and our fellow creatures on this planet at this time.

    And, yes, the C02 levels could get lower, they could get back to the 180-300 ppm range to which we and our fellow species are accustomed.

    Comment by Tavita — 8 Apr 2007 @ 4:53 AM

  120. Re 67 etc regarding Nuclear Vs Coal. Just a thought but coal puts out more Uranium and other radioactive elements than nuclear power plants ever do. Coal is a killer in many ways, it is just a bad substance overall apart from the energy it contains of course. Nuclear waste is tiny relative to coals record.

    Regarding electromagnetic radition, there is one thing that infrared is that all the others are not and that is it has the highest entropy and hence once it is heat it is in its most useless form. High energy photons such as UV, Xray and Gamma are much more useful than infra red. Of course there are heat engines etc but in terms of physics entropy is the slipperly slope to uselessness.

    Comment by pete best — 8 Apr 2007 @ 5:04 AM

  121. Re. 110 the issue is not absolute levels but rate of change. Mass extinction events occur when the rate of change is greater than species can adapt to.

    Comment by Dave Rado — 8 Apr 2007 @ 6:02 AM

  122. Re 110 “Could it get much lower than it is now?”
    Well, it was about 30% lower at the start of the industrial age. So, yes, it could be much lower than it is now.

    Comment by Chuck Booth — 8 Apr 2007 @ 6:32 AM

  123. [[Even supposing that "terrorists" could steal nuclear material from a reactor, the harm that they could cause with it would still be less than that caused by fossil-fuel emissions. ]]

    That’s why I’m for renewable sources of energy.

    (Of course terrorists would have a hard time stealing material from a reactor. It’s much more likely someone would sell it to them. Or that they would hijack a truck en route.)

    Comment by Barton Paul Levenson — 8 Apr 2007 @ 7:04 AM

  124. [[ Carbon-dioxide is NOT a pollutant, it's plant food!! Without it, every green plant in the world would die. ]]

    True, but we don’t need 300-600 ppm for that.

    Comment by Barton Paul Levenson — 8 Apr 2007 @ 7:06 AM

  125. [[Sorry guys I couldn't keep up with the blog that I love most for the past several days. Been spending too much time shoveling this April snow out of my driveway. Sister down in Louisiana tells me it's gonna be a 38 degree Easter Sunday there. ]]

    Oh, well clearly that disproves global warming. Thanks for letting us know.

    Comment by Barton Paul Levenson — 8 Apr 2007 @ 7:07 AM

  126. So, Kurt, hoping for a comeback by the dinosaurs? The reason CO2 is lower now than 500 million years ago is because all that carbon had been sequestered in resorvoirs of coal, oil and natural gas trapped deep under sedimentary strata.
    Did it occur to you that maybe the environment of the time was a reason human-like creatures did not exist 500 million years ago. We’ve evolved during carbon-poor conditions and all of the infrastructure of our civilization has evolved during a period of exceptional climatic stability. That is precisely the concern.

    I also see William Gray is at it again claiming that all climate change is due to ocean currents. Denial is alive and well in the US of A.

    Comment by Ray Ladbury — 8 Apr 2007 @ 7:12 AM

  127. Frederick,

    I am not measuring the Coriolis force. Of course the Earth is the main frame of reference. You can pick your frame of reference as large or as small as you want depending on the problem. But simply saying every moving thing in the northern hemisphere is deflected to the right (which is true) does not help students understand why subtropical gyres rotate clockwise and subtropical hurricanes rotate counter clockwise when they are both in the northern hemisphere. That’s the issue I am trying to tackle. I am not discussing the forces involved or their magnitude.

    Comment by Figen Mekik — 8 Apr 2007 @ 7:56 AM

  128. “Sorry guys I couldn’t keep up with the blog that I love most for the past several days. Been spending too much time shoveling this April snow out of my driveway. Sister down in Louisiana tells me it’s gonna be a 38 degree Easter Sunday there.”

    I live in Grand Rapids, Michigan. It snows here ALL the time. Big chunks of snow the size of my fist fall out of the sky on a regular basis. And if it’s not snowing then it’s raining or at least cloudy. Really cloudy though, thick clouds, dark, ominous most of the time. When we see the sun, we are thankful (less than 90 days out of a year are sunny here). Don’t get me started… BUT, this has nothing to do with global warming. Nor the fact it is unusually cold in Louisiana. That would be like saying my grandma smoked like a chimney but lived healthily til she turned 98. Great for your grandma, but it doesn’t mean smoking does not cause lung cancer, and we can only hope she was careful to not expose her family to second hand smoke.

    Comment by Figen Mekik — 8 Apr 2007 @ 8:06 AM

  129. The quiz link is broken

    Comment by Zach Mayer — 8 Apr 2007 @ 8:30 AM

  130. re: 126. Like many deniers who have posted here, Gray’s comments have become shrill and repetitive and sound desparate. It is unfortunate that he gets press for a topic that is out of his area of expertise. Just look at the repetitiveness of the arrogant “look-what-I-know-that-thousands-of-climate-scientists-don’t-know” comments from layman deniers here. The latest being “CO2 is not a pollutant”. Laughable if not for the fact that 1. apparently some people beleive such rubbish, and 2. the “issue” has been clearly discussed already here at And all it would take would be a simple search in the “Search” box at the top of the page for the deniers/drive-by posters to read and learn about it.

    Comment by Dan — 8 Apr 2007 @ 8:48 AM

  131. Figen- Re120 You have your work cut out for you, but at least we knw the region of the spectrum richest in factoid radiation — Such statements as
    “there is one thing that infrared is that all the others are not and that is it has the highest entropy and hence once it is heat it is in its most useless .”

    Radiate primarily from the AM radio band. Perhaps RealClimate’s foundation sponsors should invest in some commercials on the Rush Limbaugh show, since you already have to field a lot of his past buy-date culturual merchandise.

    Here’s an Ozone-relevant example:
    “CALLER: So you don’t believe in global warming? (scoffs)
    RUSH: No.
    CALLER: Or that the large ozone hole?
    RUSH: No. Wait, wait, wait, wait. I –
    CALLER: Or that humans created the ozone, destruction of the ozone.
    RUSH: No. No, no, no. I don’t. Because the hole closes every year and we don’t do anything to close it. ”

    Whole thing at

    Comment by Russell Seitz — 8 Apr 2007 @ 8:52 AM

  132. So, Ray, there are a lot of incredible assumptions in your #126, but let’s start here. Maybe I’ll be surprised to hear something that “climatologists” don’t know:

    Just what is it, exactly, that “science” will do, through our friendly political and diplomatic class, of course, that we are sure will keep our atmosphere at the right level of, as you say, “carbon-poor” (I assume you know precisely what this level ought to be since you obviously know things like why there were no “human-like creatures” 500 million years ago) so that “exceptional climatic stability” continues for us and our posterity?

    When that question is answered in a fashion that we mere laymen can understand, you will have support. It would also be nice if the politicians could understand it, too. Sometimes they can be prone to opportunism for their own benefit. Can we be assured we, as a nation, can understand your offered “cures” well enough to avoid fueling Big Government, an over-regulated society, and the loss of our freedoms afforded by the US Constitution? Or are these questions beyond the scientists pay grade? I hope not.

    Comment by BillOGoods — 8 Apr 2007 @ 9:29 AM

  133. RE #108 & “Carbon-dioxide is NOT a pollutant, it’s plant food!!”

    It seems I read somewhere that too much CO2 could actually harm plants. I know that many of the same measures that cause GHG emissions also contribute to acid rain, which harms farm soil & plants & trees. And CO2 is harming sea life by making the oceans more acidic.

    And I remembering seeing in IS IT HOT ENOUGH FOR YOU? a science experiment with growing plants in a CO2 enriched greenhouse. What they found was that weeds (C3 plants) greatly outdid food crops (C4 plants), and that insects ate more of the crops, because while the crops were somewhat larger, they were nutritionly poorer.

    So net result of enriched CO2 – more damage to food crops, crops that are nutritionally deficient, and decline of sea life.

    That could even be considered a form of totalitarianism, changing the farmers’ and our crops in ways we don’t like without our permission. So denialists of the anti-totalitarian stripe, not reducing our GHGs will lead to eco-totalitarianism, a world controlled and harmed by high GHG-emitters jerking everyone around against their will.

    And then, of course, if you add in the effects of GW (beyond simply harms from the addition of CO2 to the atmosphere), the prognosis for life on earth worsens even further.

    Comment by Lynn Vincentnathan — 8 Apr 2007 @ 9:38 AM

  134. Kurt, you’re talking about a much simpler world, one much less favorable to life as we know it.
    No conservative could want to turn the world back to what it was when CO2 was that high.

    Life removed most of that carbon — made it into coal — while making Earth habitable for us.

    “The Phanerozoic ….half a billion years …. built up complex and diverse ecosystems, and life has evolved … millions of species ……. This eon can also be considered (as suggested by Dr James Lovelock …) the modern period in the life of Gaia … characterized as much, if not more, by the presence of abundant free oxygen as by the existence of multicellular organisms or fossil-bearing rock strata.”

    “Gaia” isn’t your enemy. It’s you and your friends and relations, all those multicellular organisms.

    Comment by Hank Roberts — 8 Apr 2007 @ 9:42 AM

  135. “… CO2 is not a pollutant …”

    Great. Tell the Navy so they can stop wasting our tax money by removing harmless CO2 from submarine air.

    Comment by J.C.H — 8 Apr 2007 @ 9:46 AM

  136. What Would JC Do About Global Warming?

    Seems like an appropriate question to ask on a weekend that celebrates forgiveness and renewal. According to CNN, nothing.

    In a telephone interview with Dr. John Christy yesterday (you thought I was talking about the other JC didn’t you!!!), global warming is not a real problem. He said that the recent IPCC report and the previous one greatly exaggerate the warming due to greenhouse gases, citing his own data set accumulated over many years as the authoritative source.

    The CNN interviewer pointed out that Christy was one of a handful of climate skeptics and that over 2300 scientists involved in the preparation of the IPCC reports represented the majority view on the issue. However, Christy said that not all 2300 wrote the SPM or its underlying document and that he himself was a member of the 2300. Truth is, various sections are assigned to different groups of authors who have a specialty in that field. A report actually written by 2300 people would never get finished.

    He did not go into specifics about why the IPCC reports were wrong, instead noting that the doubling of human life expectancy in the 20th century was due mostly to fossil fuels and that problems in Africa said to be exacerbated by global warming in this century would best be dealt with by providing the beleaguered residents of that continent with better governments.

    Who can argue with the former Kenyan missionary about the need for better governments for Africa and yes, Reddy Kilowatt and the Exxon Tiger have improved our lives. But a lot of the increase in life expectancy is due to disinfection of drinking water and the availability of vaccines and antibiotics. Having a Lincoln Navigator in the driveway may correlate well with how much health insurance you can purchase, but a Ford Fiesta will still get you to the emergency room.

    I was wrong when I recently said that the time has passed for the climate skeptics. They’ve just morphed into armchair economists and political scientists. Now how can we forgive that.

    Comment by Alvia Gaskill — 8 Apr 2007 @ 9:55 AM

  137. A scientist has more responsibility/authority in politics than other citizens on this issue only to the extent that he/she can make sure that our fellow citizens–and the criminals (oops, I mean politicians) they elect–are informed with the best science we can determine. This website is an excellent contribution in that direction.
    Do I know exactly how much carbon is right? No. Here’s what I do know. Climate seems to be relatively stable right now. We know we have returned to roughly the same climate patterns after a variety of small perturbations. However, we know that climate is only ever quasi-stable, and if we (or nature) ever perturb it sufficiently, it will depart the region of phase space where it is relatively stable. We are now perturbing the climate to a much greater extent. When does climate become unstable? We don’t know. We do know that the faster and more we perturb it, the more likely it is to become unstable. So the answer is to slow down the speed with which we are changing climate. To do that we need to slow down (note I don’t say stop) our emissions of greenhouse gases. We do this by means of increased conservation and diversifying our sources of energy–with emphasis on renewable and nuclear power. We also invest in technologies to mitigate the effects that will inevitably occur.
    Now, here’s the deal. CO2 emissions are rising exponentially. There are known positive feedbacks in the system–that is, once we get above a certain temperature, they will start emitting even more greenhouse gases. So anything we do will take time. Moreover, the sooner we start, the better will we be able to develop coping strategies without resorting to draconian measures or “big government” solutions. So, this is where people like YOU come in. Carbon credits, if properly handled, could be a way of introducing market forces. What’s the best way to handle them that keeps government from interfering to the maximum extent–and maybe makes a little money available for research into solutions? This is where economists, etc. can contribute. The climate scientists already have a pretty good handle on the climate itself.

    Comment by Ray Ladbury — 8 Apr 2007 @ 9:56 AM

  138. Re #123: [That's why I'm for renewable sources of energy.]

    Well, who isn’t? The problem (as we’ve discussed before) is that there’s not enough of it that can be harnessed, dependably, with current technology, to do everything that needs to be done.

    [Of course terrorists would have a hard time stealing material from a reactor. It's much more likely someone would sell it to them. Or that they would hijack a truck en route.]

    Which ducks the point I was trying to make. Assume the worst case: instead of stealing the nuclear material, our “terrorists” can just go to the friendly folks in Tehran, Pyongyang, or Islamabad, and get their nuclear weapons off the shelf. What can they do with those weapons that will have worse consequences for the world than continuing to emit CO2 from fossil-fuel plants?

    Comment by James — 8 Apr 2007 @ 11:02 AM

  139. Re: Coriolis spin

    Perhaps its best to inform your students that a mass of air in the northern hemisphere, which appears not to be moving at all, is actually already spinning (counterclockwise as viewed from space), along with the rest of the planet earth.

    When that air mass contracts inward toward a low pressure center (as in a hurricane), its spin speeds up, just as a figure-skater does when drawing his/her arms in while spinning. Then it’s spinning faster than the rest of the earth, so to us earth-bound humans its spin is apparent (and counterclockwise when viewed from space, in the northern hemisphere).

    Comment by tamino — 8 Apr 2007 @ 11:03 AM

  140. Re #128
    “Snows all the time here”

    OK, it is a good place to study snow. The guys at NCAR in Boulder are likely jealous.

    Comment by Aaron Lewis — 8 Apr 2007 @ 11:48 AM

  141. Re #138 “Assume the worst case: instead of stealing the nuclear material, our “terrorists” can just go to the friendly folks in Tehran, Pyongyang, or Islamabad, and get their nuclear weapons off the shelf. What can they do with those weapons that will have worse consequences for the world than continuing to emit CO2 from fossil-fuel plants?”

    Set off a full-scale nuclear war, deliberately or otherwise. Say you’re an extreme Islamist, Nazi, or Unabomber-type anti-industrialist, who has managed to get hold of a nuclear weapon. You hate both the USA and its main potential enemies, Russia and China. So why not use the bomb to attack one of them, while casting suspicion on another? Put it in a shipping container, ship it to a major port in one of your target states, plant evidence that another of your hate-objects is responsible, and set it off. The government of any nuclear weapons state attacked in this way would be under enormous pressure to retaliate with a nuclear attack on some other state that could plausibly be identified as the perpetrator, or as aiding the perpetrator. Suppose the USA is attacked and the signs appear to point to Russia, or vice versa? How confident are you there would not be nuclear retaliation? And if there was, would not spiralling counter-retaliation be all too likely? That this would happen is the very cornerstone of “deterrence”. (It is in fact far more likely that the initial shipping-container attack would be performed by a state, not by non-state actors, simply because nukes are hard to build, and no government is likely to hand a nuke to a group they do not control. However, this point is not crucial here.) The more states have nuclear weapons, the more chance of such weapons being used (except, perhaps, in the shift from one nuclear-armed state to two), either overtly, or in the covert way I have described. The greater part nuclear power plays in future energy production, the greater the chances of more states acquiring nuclear weapons: a civil nuclear power program provides excellent cover for a nuclear weapons program; civil nuclear power generates bomb-making materials; and selling nuclear materials, technology and knowhow is an obvious way to offset the costs of either a civil or military program.

    If a major expansion of nuclear power could prevent disastrous climate change, and no other plausible measures could, then the risks of accident and proliferation would have to be taken – but the most detailed analyses I’ve read (by the Tyndall Centre and George Monbiot, both concerning the UK) suggest otherwise. In any case, only one of the major sources of GHGs – electricity generation – could be much reduced in the next few decades by either. Far more profound changes to industrial society than any specific energy-generating technology are required if disaster is to be averted.

    Comment by Nick Gotts — 8 Apr 2007 @ 1:37 PM

  142. …,perhaps the most effective method for eradicating misconceptions at every level is going to be investing large quantities of time, money and effort into educating primary and secondary school educators. NSF has many programs that fund such efforts, but much more effort is clearly needed on a global scale. …

    A few years ago in the U.S., education about earth science principles was done by local meteorologists in their local communities. That mostly stopped when global warming was made out to be political and controversial by National Weather Service (NWS) supervisors and NOAA administrators. NWS refused any responsibility for public education on global warming as early as 1993 when they refused national media requests to talk about global warming in relation to the 1993 Midwest summer floods. NOAA administrators reinforced NWS refusals from 2001 (Bush) to current (still Bush).

    Comment by pat neuman — 8 Apr 2007 @ 5:14 PM

  143. The misuse of temperature trends and anecdotal reports of cold weather is a common skeptic’s theme; the posts about cold weather are one example. The Exxon-funded site also publishes a weekly temperature record that alwas shows a local cooling trend: “To bolster our claim that “There Has Been Little Net Global Warming Over the Past 70 Years” each week we highlight the temperature record of one of the 1221 U.S. Historical Climatology Network (USHCN) stations from 1930-2000.”

    This approach is similar to that of a person who attempts to prove that rivers flow uphill. If you look at a river flowing over rocks, you can always find local areas where eddies result in upstream currents. If you run all over a river looking for such features, and only measure the flow direction at such features, you produce a dataset where every measurement shows upstream flow… and then you can claim that rivers flow uphill, and that you have the data to prove it.

    Also, nuclear is a dead end for the same reasons that fossil fuels are a dead end – there is a ver limited supply. Eventually all human energy demands will be met using various solar conversion strategies – wind power, solar thermal, solar PV, solar and biofuels – and the sooner the better. We’ll need very energy efficient technology as well as new energy storage technology to make this happen, at which point nuclear and fossil fuels will be largely obsolete. There will be no need for energy-expensive carbon sequestration because there will be no need for fossil fuels.

    Comment by Ike Solem — 8 Apr 2007 @ 6:13 PM

  144. Re #143: Ike Solem — Unfortunately the ‘limited supply’ of coal is very large. Enough to bring atmospheric carbon dioxide to about 4000 Gt if all burnt. To put that in proportion, so far humans have added about 300 Gt of carbon dioxide to the atmosphere…

    Comment by David B. Benson — 8 Apr 2007 @ 6:52 PM

  145. The Twin Cities NOAA National Weather Service (NWS) statement below is an example of a special cold weather summary report for public interest.

    One of the Coldest First 7 Days of April on Record

    The following table highlights the top 15 total heating degree days for the first seven days of April for selected locations. Heating degree days are computed by adding the high and low temperature of the day, and then calculating the average. The average is then subtracted from a base temperature of 65 degrees to determine the heating degree temperature for that day. As you can see, this first week in April ranked among the top 10 at 4 of the 5 locations. This translates into one of the coldest, if not the coldest, first weeks of April.

    Table of coldest by year based on heating degree days at NWS link below.

    The text and table highlight recent cold observations versus historical data at 4 climate stations in MN and one in WI.

    I have not seen any reports on new records for annual mean temperature set in recent years, year after year.

    Including 2006, which was well above normal (1971-200 averages) for annual mean temperatures at all climate stations in MN and WI, a few stations reached a 10 year consecutive mark of having above average annual mean temperatures (Cloquet, MN COOP, 1911-current) and Spooner Experimental Farm, WI COOP, 1894-current). Many stations in MN and WI have had 9 years of consecutive above average annual temperatures, including 2006. Prior to the current streaks, the longest previous number of consecutive above average annual temperatures in the period of record (110 years) has been 4 or 5.

    I don’t think NWS or NOAA or anyone that I know of has been reporting on the streaks of years above historical average temperatures, but me. Shouldn’t that be a responsibility of NWS? NOAA’s NWS has about 120 offices in the U.S. with a staff of about 5500 meteorologists and technitions. I’m only doing it because it seems no one else is.

    Comment by pat neuman — 8 Apr 2007 @ 7:39 PM

  146. Pete Best: What do you mean by “there is one thing that infrared is that all the others are not and that is it has the highest entropy and hence once it is heat it is in its most useless form”? Infrared radiation is heat. Sensible heat refers to the energy in the excitation state of molecules in a substance. Let me quote from raypierre’s e-mail to you because he is far more eloquent than I: “It’s true to say that the Earth can’t lose heat by conduction “to space,” so it needs some other means. Fourier was the first to realize that this ‘other means’ was infrared radiation.”

    Tamino: Thanks!!

    Comment by Figen Mekik — 8 Apr 2007 @ 8:10 PM

  147. RE#144 – that’s true enough. Here’s the breakdown (I posted this some time ago, but here it is again)

    Now, the estimated total fossil fuel resources left to burn (as of 2000) from
    Conventional oil – 263 (Gigatons of Carbon, GtC)
    Shale oil, etc. – 525
    Natural gas – 422
    Coal bed gas, etc – 450
    Coal – 3370

    The preindustrial atmospheric carbon dioxide content (as carbon) was 580 GtC (280 ppm) and in 2000 was 750 GtC (380ppm)

    How many gigatonnes of carbon per year stay in the atmosphere? Around half, so if current total CO2 emissions (as carbon) are at 7.2 GtC (only looking at fossil fuels), then around 3.6 Gt of carbon stay in the atmosphere each year – and it’s worth wondering what processes account for the uptake of the other half. See the Woods Hole discussion of the missing carbon sink. What you don’t know can hurt you… meaning that it’s possible that more CO2 could start lingering.

    If we burn all the fossil fuel, that means adding 5000 GtC to the atmosphere, (if half stays up, that’s 2500 Gt) and warmer oceans and stressed forests will probably absorb less CO2, resulting in a minimum CO2 content of around 1500 ppm (and probably quite a bit higher, due to sink limitations.. and the oceans may degas methane and CO2 if they warm up a lot..). There’s also no reason to assume that all that CO2 wouldn’t stay in the atmosphere for millennia, either – meaning no ‘global cooling effect’ after the fuel is gone. This is a bit beyond the worst-case scenario in the IPCC report.

    One main myth is that restricting the use of fossil fuels will cause economic collapse, but that’s simply not true. Fossil fuel industry spokespeople will tell you that people absolutely need fossil fuels, and we’ll just keep burning it till it’s all gone – but the fact is that recent economics indicate that renewables become economically preferable as oil approaches $100 a barrel.

    Comment by Ike Solem — 8 Apr 2007 @ 9:08 PM

  148. Re #137. Yes, we really donâ��t want the economists interfering with the climatologists, would we. But the worst thing we could do is impose â��carbon credits.â�� Instead, what we should do is freeing up our economy and lowering taxes to create more wealth in this country so that if private parties want to start taking action to inhibit the effects of any global warming (damns to prevent flooding of property, flood insurance companies insuring high risksfor those that can’t get it otherwise, hurricane insurance companies offering coverage in areas prone to them, whatever), they can do so. See

    In this way, only those theoretically effected will pay for the effects and not the whole of society. �Carbon credits� are just a tax, and, therefore, a drag on the economy of this country and others. Ultimately, we all pay it. On totally other grounds, we should start and start now to shift to nuclear power. I agree. But try getting a plant built with the environmental nuts out there laying in the road bed ready to be crushed by the construction equipment.

    Your post is also very honest and I appreciate it, but I�m not sure you intended it.

    If we know we have �returned� to stability after other disturbances (not caused by man, I assume), why do we need to do anything at this point? Why don�t we just wait, as other smart scientists suggest, for the stable period to return? See And how do we know if it was �we� or �nature� that did the disturbing? Sounds like this would be a pretty important question to answer and we haven�t yet. And some climatologists say you guys are �cooking the books� on your data�skewing the data. See

    You also admit we don�t know why climates become unstable so, then, how can we conclude that, if the climate is unstable now, it got that way because of man? Some climatologists say we are well within normal temperatures when we look at long term weather. See Lindzen, �Climate of Fear, Wall Street Journal (4/12/2006), (must be a paid subscriber�sorry).

    Finally, how do we know that by �slowing� emissions we won�t make the problem worse in the other direction? You are speculating, you don�t �know,� that by slowing down emissions, the chance we will return to a more �stable climate� increase. That�s an assumption. Why might it not destabalize the climate in the other direction?

    Again, you will have to convince the average person of the merit of your cause�not frighten them, like Al Gore does, into acting irrationally. That hasn�t been done, Ray, and it seems like it�s very far away from happening. You seem to abdicate your responsibility in this regard. Politics and the smarmy politicians have hijacked this issue and the scientific community better catch up quickly. Problem is, they seem to enjoy going along for the ride and may lose credibility with these wild predictions.

    Finally, I just read something that I’m not going to bother to look up unless you really want to see it about the idea of a “global average temperature” is a farce and does not exist. So, if we really don’t know what the global average is, how do we know it’s significantly different from what it used to be?

    Comment by BillOGoods — 8 Apr 2007 @ 9:49 PM

  149. Many thanks for the reminder that many of those who chant the ‘phrases and praises’ of global warming/climate change often might benefit from a basic understanding of the mechanisms involved. Keep up the good work.

    Comment by Will Carpenter — 8 Apr 2007 @ 11:59 PM

  150. Re 144, I am just stating that Entropy is a measure of large scale disorder and infrared radition is more disordered than UV or Xrays for instance. Well I beleive that is the case anyways.

    Re 147, coal comes in three flavours and they carry different amounts of energy per Kilogram burned. We have used a lot of the good stuff and we are left with bitumous and sub-bitumous which is not way near as energy dense as the other sort. Hence we may have billions of tonnes of it but not a lot of energy to come from it I believe.

    Comment by pete best — 9 Apr 2007 @ 4:59 AM

  151. Re 132 BillOfGoods: In spite of the supposed right of freedom from big government, over-regulation etc. enshrined in your constitution, I, along with my children and millions of other people have a right to continue to live in a comfortable or at least livable environment. Perhaps you aren’t aware of the data on long term climate trends, or you live in a portion of the good ol’ US of A where the weather is normally crazy anyway or is particularly robust against global trends. But the situation is not looking so rosy down here in Australia. You can see the latest news on the long-running Australian drought here (the map at the bottom shows areas experiencing serious deficiencies or lowest on record rainfall). The situation we are experiencing may be a fluke and the scientists may all be wrong. But what if they are right and there is worse to come? You’re scared of regulation? Try living somewhere where water catchments are reaching critically low levels and you’ll get a real lesson in what being regulated means. In both Adelaide and Melbourne ‘dob in a water cheat’ is the new fun-for-all-the-family game where neighbors report on each other for crimes such as washing their cars or watering their roses. My grandmother’s garden, lovingly created over the course of 50 years is mostly dead because her tap water got too salty. My mother told me tonight that she’s given up carting water from the shower (showering with a bucket is a national sport now also) and has decided to replace her whole garden with drought adapted natives. Right now it’s all a bit inconvenient (unless you are a farmer off course) but one more dry year will see the panic setting in. We’ve had plenty of warning of this possibility but the politicians kept ignoring the warnings of scientists, saying that they were sensibly not going to harm economic interests by making knee-jerk decisions in response to doom-saying greenies.

    Comment by Craig Allen — 9 Apr 2007 @ 5:53 AM

  152. Re: #148 (BillOGoods)

    In this way, only those theoretically effected will pay for the effects and not the whole of society.

    This is one of the most offensive statements I’ve ever seen. How about if those who are responsible for the effects — the whole of society — share the burdern?

    It’s folks like you who give capitalism a bad name.

    Comment by tamino — 9 Apr 2007 @ 8:47 AM

  153. Frederik (#99),

    First thank you for showing me how to better explain the Coriolis effect to my students. I am very familiar with the image you posted, but I think our miscommunication stems from my dominantly ocean science background. So let me clarify. In essence we are talking about the same thing: moving objects are deflected to the right in the northern hemisphere. But I like to include a vertical component to ocean motion (and air motion too since it comes up in class) when discussing the Coriolis effect but apparently I need to clarify a drag component in this picture. Gavin helped me with the rest of this explanation. All vertical motions can be thought of simply as the result of convergence and divergence in the horizontal flow and in the absence of friction (drag at the surface) there would be no convergence/divergence and hence no vertical motion. At the surface, the drag causes the winds to converge at the center of a low pressure zone. This gives ascending motion in the center of the system. In the ocean, the Ekman flux is to the right of the winds, and so in the subtropical gyre causes a convergence in the center and downwelling there. The ocean height is higher in the centre of the gyre and so the force is radially outwards. i.e. it is a high pressure system, and naturally the currents go around clockwise.

    So, you get surface convergence in low pressure systems in the atmosphere, but in high pressure systems in
    the ocean. But the convergences are not due to Coriolis alone, but due to the drag, and that is expressed differently in the ocean and atmosphere.

    Comment by Figen Mekik — 9 Apr 2007 @ 9:52 AM

  154. [[Re #123: [That's why I'm for renewable sources of energy.]
    Well, who isn’t?

    You aren’t, presumably, since you think nuclear power is the answer to global warming. And you immediately follow your rhetorical question with why you don’t think renewable energy can do it:

    [[ The problem (as we've discussed before) is that there's not enough of it that can be harnessed, dependably, with current technology, to do everything that needs to be done.]]

    I don’t agree. Knowing just what we know now, we can replace the fossil fuel/nuclear infrastructure with renewables in a few decades at most.

    Comment by Barton Paul Levenson — 9 Apr 2007 @ 11:47 AM

  155. you think nuclear power is the answer to global warming.

    It’s certainly an answer, one of many.

    we can replace the fossil fuel/nuclear infrastructure with renewables in a few decades at most.

    Shame about the cost of solar and lack of dispatchability of wind, though.

    Comment by Paul Dietz — 9 Apr 2007 @ 2:39 PM

  156. Yeah, but if we focus for a few decades on conservation, efficiency, and solar and wind, we may buy enough time to get a serious helium-3 mining operation going on the Moon.

    Google it. There is serious interest in that route already discussed.

    It’d be smart to avoid committing to all the infrastructure needed for either big coal or big fission power plants — and creating all the vested interests that would then argue against wasting money on creating a ‘needless’ helium-3 fusion system, once the money was committed to fission piles.

    Neutron activation is the problem with all the other fission and fusion paths.

    It’s a capital mistake to invest in advance of the evidence, and capital is something better not wasted.

    The money that could be spent getting a serious step past the temptation to invest in either of those two known dirty and troublesome technologies — and the savings from not having to decommission all the avoided plants — would be huge.

    Comment by Hank Roberts — 9 Apr 2007 @ 3:46 PM

  157. Re #141: [Set off a full-scale nuclear war, deliberately or otherwise.]

    I agree with at least the possibility of your reasoning re nuclear weapons, but that was my point: whatever the level of nuclear weapon use, from one “dirty bomb” to an all-out nuclear exchange, the effects (summed over the whole Earth and time in which they’ll be felt) would still be less than what we can expect to see as consequences of AGW.

    Of course you have to figure in some estimates of how likely these things are. A chain of events starting with misuse of nuclear power might possibly set off a full-scale nuclear war, just as continued CO2 release might possibly trigger feedbacks that lead to runaway GW and extinction of most higher life forms, but neither of those scenarios is at all likely. There are also some pretty obvious ways to minimize the risks, but any discussion would quickly get us off into politics.

    [... only one of the major sources of GHGs - electricity generation - could be much reduced in the next few decades...]

    However, electricity generation can, with varying degrees of effort, replace most other uses of fossil fuels. For instance, the transportation sector could shift to a mix of EVs and plug-in hybrids. High-speed electric trains could replace air passenger travel on many routes, and could haul much of the freight that is now shipped by truck.

    Comment by James — 9 Apr 2007 @ 6:11 PM

  158. Re #154: [You aren't, presumably, since you think nuclear power is the answer to global warming.]

    Now how did you get that idea? I hope you don’t think that I have the sort of limited mind that can see only one possible approach to a problem – especially as I know we’ve discussed this before :-) Just to recap: I don’t think there is an answer to global warming. There are a lot of partial answers, and all of them will be needed if there’s to be any hope of success.

    [I don't agree. Knowing just what we know now, we can replace the fossil fuel/nuclear infrastructure with renewables in a few decades at most.]

    I have to go with the opinion of the renewable energy folks (you can find the link back a few articles – IIRC you posted it :-)) who think that renewables plus conservation can only replace something like 40-60%.

    Comment by James — 9 Apr 2007 @ 6:49 PM

  159. I think the unstated issue in terms of counter-clockwise rotation of hurricanes is that if you imagine yourself as a parcel of air that is rotating around the center of the hurricane (as it appears!) then you are constantly turning to your LEFT. That seems to contradict the nature of Coriolis forces. I suspect that this issue, which has not been clearly laid out in the discussion here, is the source of students’ confusion which Figen is trying to allay.

    Comment by Hal — 9 Apr 2007 @ 9:05 PM

  160. Re #159: Hal: Yes! :o And I’m not doing a great job. It looks to the LEFT if you look down from space, but if you looked up from the surface it would be clockwise (looks to the RIGHT). Though as the pict Frederik posted (#100) so nicely demosntrates, deflection is always to the right in the northern hemisphere.. I had a “twist your hand up” and “twist your hand down” exercise to illustrate this in class, and it looked as stupid as it sounds and didn’t help anybody. But I tried :)

    Comment by Figen Mekik — 9 Apr 2007 @ 10:59 PM

  161. I remember my sister, who was told by her teacher that the sun was a globe of glowing glass. “It says gas in the book, teacher”.

    Comment by Harald Korneliussen — 10 Apr 2007 @ 12:41 AM

  162. Re #157 James, take a look at the papers linked to at, and particularly at:

    Alan Robock, Luke Oman, and Georgiy L. Stenchikov (J. Geophys. Res, in press)

    This indicates that global nuclear war would have utterly devastating atmospheric and climatic effects – global dimming and cooling (to mean temperatures below that at the LGM 18000 years ago)and a sharp drop in precipitation, largely wiping out agricultural production for perhaps a decade, plus extensive destruction of the ozone layer. Still, at least we wouldn’t need to worry about AGW any more.

    So far as nuclear (or renewable-based) electricity generation replacing other forms of fossil fuel use: possible in the long term, no doubt, but to what extent within the crucial next 20-30 years? Even if the technical problems could be overcome rapidly, the cost of infrastructural replacement would be phenomenal – not just financially, but in terms of the increased GHG emissions involved in producing and installing that infrastructure, which would have to take place in large part before any significant shift away from fossil fuel electricity generation took place. So no technical fix, whether nuclear or renewable, is going to allow us to avoid fundamental reorientation of global socio-economic and political systems, including considerable demand reduction in rich countries – if we’re serious about preventing catastrophic AGW.

    Comment by Nick Gotts — 10 Apr 2007 @ 5:55 AM

  163. Hope someone gets this far down the thread, there is a lot of excellent discussion here!

    I found that Private Universe Video really opened up a can of worms for me. Although some of it is dated they actually went on to create a project based on the original video:

    2 years after this they revisited some of the students and created a fascinating 3 part series called “Minds of our own”:

    Every teacher should see this video if they haven’t already (especially science teachers!). It explores Piaget’s idea of constructivism in the classroom, and how children build up their world using ideas they have experienced concretely. At some point in the video the penny dropped for me and it was like I had this flashback to my teenage high school years. The reason I struggled with High School was because I was so interested in grasping the science that I didn’t have enough opportunity to gain a full understanding before the next concept was ushered in the door. By the time I reached 10-11 grades my head was full of ideas, but I couldn’t keep up anymore as more abstract understandings were required. I clearly remember my high school teacher trying to explain Faraday’s light experiments as a lead into physics and I just didn’t get it (how can light be a wave and a particle? sounded like something a zen monk could spend his life meditating on!). At that point I totally lost it, fell behind and failed senior physics. My fellow students had happily memorized the entire curriculum and they fared well on the tests. But what about basic science understanding? I had gained an understanding that the seasons were governed by the tilting of the earth, not the distance of the sun..which graduates often fail to grasp. One teacher in the series states that there is only enough time in a year to present 15% of the curriculum content properly so that students can grasp it. And we wonder why students switch off and drop many high order thinking concepts have you as an adult had to learn in the last fortnight? And yet we expect maturing minds to grasp such ideas so quickly without concretely experiencing these abstractions?

    Comment by beyondtool — 10 Apr 2007 @ 8:28 AM

  164. About the quiz:

    I had some recent interactions with the eductors at Oakland who developed the quiz, namely Mary Stein and John Coughlin. They say it has been taken off line for revisions based in part on your comments and in part on comments here:
    They also say it was developed for preservice elementary school teachers who had not yet had college level science courses which is why some of their explanations were so basic.

    I, for one, hope their revised quiz comes back on line soon as this is quite an invaluable service both to diagnose and to cure misconceptions.

    Comment by Figen Mekik — 10 Apr 2007 @ 11:52 AM

  165. we may buy enough time to get a serious helium-3 mining operation going on the Moon.

    You would do well to be extremely skeptical of this. The concentration of 3He in the lunar regolith is very small, something like 10ppb on average. The energy required to extract it will be a significant fraction of the energy it can ultimately produce, even assuming we had workable and economical fusion reactors that could burn D-3He (which is something like 50 times less reactive than DT). Energy infrastructure on the moon (to produce the energy needed to drive the extraction) will be very expensive, per watt, compared to energy infrastructure on Earth. It’s very difficult to see how this could ever be competitive, never mind in a few decades.

    Comment by Paul Dietz — 10 Apr 2007 @ 2:56 PM

  166. Re. 165

    I have to agree. Fusion is a pipe dream at this point with folks not generating enough net energy to use fusion as a primary energy source. I would love to see it realized however but after 40 years (Of admittedly hard work) it is hard not to be underwhelmed.

    We also have not reliably solved the question of viable energy storage with renewables. Current batteries are not the solution as we already have problems with toxic heavy metal pollution. (And to think of all that mercury in “green” CFLs!) And in any case, the semicon industry is not green and it is very power and resource hungry. (I would know I work in this field.) Scaling Solar will not be as cheap and clean as you think.

    People latch on to Nuclear fission becuase it is here now, and mature. I just don’t like the hazard of the spent fuel.

    Lets suppose that fusion were ready now, aside from spent fission fuel rods, fusion reactors have all of the dangers of fission reactors:
    1) Neutron activation of all components of the reactor.
    2) Loss of coolant or magnetic containment could be a disaster, with the added benefit of a massive hydrogen explosion as a worst case scenario.
    3) It is trivial to use fusion/fission reactors to bombard U238 to create plutonium to use in nuclear weapons for bad guys.


    Comment by Jim — 10 Apr 2007 @ 11:03 PM

  167. >Helium-3
    Paul, I realize the concerns. Buying time for something that doesn’t produce either CO2 or neutrons — that doesn’t have a huge toxic waste stream as part of the output when the whole process and cleanup are considered as costs.

    You want “competitive” — I think the next energy development we invest in first has to be “survivable” — that’s my criterion for developing a successful energy source going forward.

    If we instead use up the cheap and easy energy sources — the quick and dirty ones — we’ll be taking the easy, obvious, seductive path. No, there’s not enough power to live the way we’ve been living. Look at any city at night from the air. Measure the ‘urban heat island’ — waste energy.

    If we had to do it right — we could. Don’t we? can’t we?

    Even if it meant not spending and making and spending and making, for long enough to look beyond the quick and dirty answer?
    Even if we had to be — very, very —- conservative, and careful, and really aim for a future that the next generation or two would be able to live with and make work and leave them the huge freedom to decide when they’re so much smarter, what to build next that will take up most of the capital and create most of the costs they’ll have to handle?

    Why leave a problem instead of a pile of capital? What happened to being chary and careful and saving for future better choices?

    Comment by Hank Roberts — 11 Apr 2007 @ 12:15 AM

  168. [[We also have not reliably solved the question of viable energy storage with renewables.]]

    Modern solar thermal plants store enough excess heat in molten salts to enable them to run at night and during bad weather.

    Comment by Barton Paul Levenson — 11 Apr 2007 @ 10:29 AM

  169. Hank: I think you are still grossly overestimating the feasibility of lunar 3He mining. Doing it in a few decades on anything but a tiny, micro-pilot scale is just not in the cards. And competitiveness is the issue — if it requires more effort than terrestrial alternatives, like fission or solar, then it might as well not exist at all.

    You are wrong, btw, that D-3He fusion produces no neutrons. In fact, it produces at least 5% of its energy in neutrons, from DD (and some DT) reactions. The proposed advantage is that the neutron flux is low enough that the first wall of the reactor doesn’t have to be replaced every couple of years due to radiation damage. You still end up with a reactor core too radioactive for hands-on maintenance, and a reactor in which the core is far more complex, and hence expensive and likely unreliable, than a fission core of the same power.

    Why leave a problem instead of a pile of capital? What happened to being chary and careful and saving for future better choices?

    Foolishly wasting our children’s inheritances on infeasible boondoggles does them no good either, wishful thinking notwithstanding.

    Comment by Paul Dietz — 11 Apr 2007 @ 10:50 AM

  170. Hello every1.

    I have to say Iâ??m very surprised of most of the commentaries Iâ??ve read about the « major nuclear accident still to comeâ??.
    This accident already took place in 1986 in Tchernobyl. The last report of International Atomic Energy Agency published a report in 2005 estimating the life cost of the Tchernobyl â??incidentâ?? to about 3000 people. Iâ??d have to say those numbers are quite underestimated, at the very least by a factor of ten, more probably by a factor of 100. The numbers of the IAEA would be a laugh if they were not an insult for concerned populations that still have to suffer today from the effects of radioactivity, mainly the inhabitants of the small country of Belarus (where 75% of the radioactive particles felt after the explosion of the reactor), and the Russian volunteers who worked during two years after the catastrophe on the mainly contaminated areas.
    No serious medical follow-up of the tens of thousands of volunteers have been realized after their return from Tchernobyl, mostly because of denial policy of USSR and the collapse of the medical system in Russia after 1990, but some non official numbers talk about a twenty to fifty percent death rate to this day.
    Concerning the Belarusian people, it has to be noted that millions of them were directly contaminated during the celebrations of the working day on the 1st of may 1986, when they were asked by the soviet direction to celebrate in the street while at the same time the radioactive cloud coming from Tchernobyl (at the border of Ukraine and Belarus) was passing over Belarus. To this day and due to the denial policy of the Belarusian president Alexander Lukachenko (which is considered as being the last dictator of Europe), the few scientists who tried to work seriously on the question and started to raise the question of health effects of Tchernobyl on populations are reduced to silence. Professor Youri Bandazhevsky, director of the Gomel Medicine Institute in Belarus, was put in jail for fallacious reasons after starting studies on the effect of caesium 137 on childâ??s health. And heâ??s just one example. In Belarus today, there is still a large portion of territory completely forbidden to the populationâ??s access, and people live with the consequences of Tchernobyl everyday. Local doctors living in the southern part of the country (the most exposed to radioactivity) report serious health problems for about 80% of the children born after the catastrophe, and countless (probably tens of thousands) abortions and deaths at birth due to radioactivity effects.

    I wanted to put this in the discussion, thirst because in a scientific and impartial debate like the one that has been raised here about nuclear power all elements should be taken in consideration. Secondly because I think itâ??s the best example of what policy can do to science when it gets the control of it. This is a support to all the scientists working on GW, and who try to stay away from politics and have an impartial and independent view on the problem.

    For those whoâ??d like to know more about the subject, Iâ??d like to recommend the books of Svetlana Alexievitch, a Belarusian journalist (not a scientist, sorry :) ) who as been censored and banned from her country to have raised the Tchernobyl issues.

    Keep up the good work here in RC :).

    Comment by nicolas L. — 11 Apr 2007 @ 11:20 AM

  171. Re #170: [This accident already took place in 1986 in Tchernobyl. The last report of International Atomic Energy Agency published a report in 2005 estimating the life cost of the Tchernobyl â??incidentâ?? to about 3000 people. Iâ??d have to say those numbers are quite underestimated, at the very least by a factor of ten, more probably by a factor of 100.]

    How do you derive those numbers? AFAIK the actual, verifiable number of deaths was something under 50. The larger estimates (which it seems nobody can actually verify) basically seem to come from using a linear dose response model of radiation exposure.

    There are two problems with this: first, nobody has ever observed it, and the claimed number of deaths should certainly be statistically observable. Second, the body’s response to environmental insults is generally not linear. Instead, there is a threshold below which there is little or no response, or even a beneficial one. (Consider vitamins, micronutrients, or even water.)

    Then too, you have the example of all the other life forms in the so-called “Dead Zone” around Chernobyl. Far from being dead, it’s a nature preserve, and perhaps the most ecologically healthy one in Eastern Europe.

    Comment by James — 11 Apr 2007 @ 5:54 PM

  172. Molten Salt? Cute. It is a neat idea but is only prototyping at this point. Some potential problems though. To really use this for public consumption would require storage for more than 16 hours and a power density greater than 15Mw. (Solar Tres) It is fascinating technology (looked cool in the movie sahara too!) but it is not feasible for the scale of the problem at this time. If that 100Mw one is completed and works well I will sit up and take more notice.

    Some issues remian.
    1) more storage such that the system will run longer periods without the sun, such as periods where the sun is blocked long periods of time due to bad weather. (ie. storms hurricanes.) At this time it runs only long enough to greet the sun the next day. (They have a nice plot of it here.)

    2) Power output per unit land area is very high, and excludes this type of power generation from becoming a “cottage” power source.
    3) It needs to work during the winter.
    4) It still depends on other forms of power to keep the plant running if it has to shut down do to loss of energy from the sun and storage tank. (This requirement is very small.)
    5) Power density. 15MW production is like trying to fix hydro dam rupture with a tarp and some duct tape! Even 100MW is not enough when the average power station these days is .5 to 1 GW.

    Comment by Jim — 11 Apr 2007 @ 9:14 PM

  173. Re : 72

    Iâ??m putting here two links if you want to play with the numbers.

    The link to the official IAEA report that acknowledges 4000 casualties:

    The link to an independent European study; that talks about more than 30000 casualties:

    I personally get my numbers from the Belarusian doctors and radiobiologists I talked to, which are not official numbers of course as long those people would be arrested if they dared to publicly talk about it, as it already happened.

    Concerning the wildlife around Chernobyl, it is true it has become one of if not the richest natural area in Europe, but mostly for one reason: there is no man anymore in a very large perimeter, a condition you can find nowhere else on the old continent. There are actually no studies about the mutation rates and death rates of animals and plants in the region to my knowledge, so I cannot say much more about it.

    Finally about the urban legend that radioactivity at low level is good for health, I think it could take a nice place in the story of scientific misconceptions. Inhabitants living in regions with granite soil (slightly more radioactive than other types of soils) are exposed to higher cancer rates directly due to radioactivity, studies have been done notably in the French Massif Central areas. Talking about France again, it is acknowledged now by the French health ministry that radioactivity coming from the Chernobyl cloud that passed upon France in may 1986 is the direct cause for higher cancer rates, notably in eastern France, while radioactivity deposits were hundreds of times lower than the ones found in some regions of Belarus and Ukraine.

    Comment by nicolas L. — 12 Apr 2007 @ 2:42 AM

  174. Re #162 I’m going to partially row back from my claim that nuclear/renewable derived electricity couldn’t significantly affect the transport sector in the next few decades. Aside from high-speed trains substituting for air travel, which James mentioned, there are possibilities with electric cars that wouldn’t require as much technical advance or infrastructure as I thought. Batteries have limited range and take hours to recharge, but Monbiot attributes to “energy expert Dave Andrews” the idea of a network of battery-swap stations. Of course, neither of these ideas is going to be easy to introduce in a way that really helps. In continental Europe there are already quite extensive networks of high-speed trains, but air travel is nonetheless growing fast. Electric cars don’t have, and probably won’t in the near future, the “performance” so beloved of petrolheads (as we call them in the UK); and you have the familiar problem of very few electric cars so no battery stations so very few electric cars. In both cases, serious government intervention backed by public opinion would be needed to push up the cost of fossil fuel used in transport.

    Comment by Nick Gotts — 12 Apr 2007 @ 5:25 AM

  175. [[Then too, you have the example of all the other life forms in the so-called "Dead Zone" around Chernobyl. Far from being dead, it's a nature preserve, and perhaps the most ecologically healthy one in Eastern Europe. ]]

    Super! Then, of course, you’d have no problem moving there yourself, would you. Why not do that, and show how much you believe what you’re saying?

    Comment by Barton Paul Levenson — 12 Apr 2007 @ 7:24 AM

  176. [[Then too, you have the example of all the other life forms in the so-called "Dead Zone" around Chernobyl. Far from being dead, it's a nature preserve, and perhaps the most ecologically healthy one in Eastern Europe. ]]

    “Ecologically healthy” isn’t the same as healthy for the individual. Many of the best wildlife sites in the UK are owned by the Ministry of Defence, and are or were used by the army as firing ranges. They abound in wildlife, because the public are not allowed in – because of the risk of getting hit on the active ranges, and of unexploded ordnance. Anyone allowing their children to play there would be criminally irresponsible.

    Comment by Nick Gotts — 12 Apr 2007 @ 8:17 AM

  177. Correction for my post.

    the second point should read:

    2) Power output per unit land area is very low and excludes this type of power generation from becoming a “cottage” power source.

    Comment by Jim — 12 Apr 2007 @ 11:07 AM

  178. I would suggest — particularly in a forum that is specifically about climate change — that the question to be put to nuclear advocates who assert that expansion of nuclear power is “the answer” to global warming, or that “no one can be serious about addressing global warming unless they support an expansion of nuclear power” is not the very real question about the safety of nuclear power (e.g. pollution from uranium mining, high level nuclear waste, terrorism, plant safety, etc).

    Rather, the key question is whether their claims regarding climate change are legitimate.

    That is to say, is it in fact true that an expansion of nuclear power is the crucial thing that needs to be done to reduce GHG emissions? Would an expansion of nuclear power reduce GHG emissions more than other alternatives? Is an expansion of nuclear power the only feasible way to reduce GHG emissions by as much as they need to be reduced, as quickly as they need to be reduced? Would any plausible, feasible expansion of nuclear power even have a significant impact on reducing GHG emissions in the time frame in which that needs to happen to prevent catastrophic climate change?

    I think the answer to all of those questions is NO. And in that case, discussion of the risks and dangers and harms associated with nuclear power is entirely moot, with regard to the climate change issue.

    So, I would ask nuclear proponents who are actually knowledgeable about nuclear power technology and the nuclear power industry (paging Jim Dukelow) to outline a realistic, plausible, feasible scenario for expanding nuclear electricity generation beyond the existing 435 nuclear power plants world wide — keeping in mind that by some estimates it will be necessary to build as many as 80 new nuclear power plants in the coming years just to maintain the existing level of electricity generation from nuclear power — and then explain how their proposed expansion plan will reduce GHG emissions, by how much, and by when.

    For example, according the the nuclear industry, the 435 existing nuclear power plants presently produce 16 percent of the world’s electricity. So, if we doubled the number of power plants (which is a far bigger expansion than even what I have seen from the nuclear industry), and assuming that total electricity production and demand remains constant, nuclear power would then produce 32 percent of the world’s electricity. If all of that expansion went to replace existing coal fired power plants, it would reduce GHG emissions by some amount.

    If that doubling of nuclear capacity occurs while electricity production and demand is growing, while probably at the same time additional non-GHG-sequestering coal plants are still being built, nuclear might not reduce GHG emissions at all, but only reduce their growth. And if the expansion is far short of a doubling of nuclear capacity, then its impact would be much less in either case.

    As I have cited on other threads, recently the American Solar Energy Society published a report showing how full implementation of existing efficiency and clean renewable energy technologies (e.g. solar, wind, biofuels) could reduce US carbon emissions by 60 to 80 percent in the next 20 to 25 years. I have not seen a similar plan from the nuclear industry, showing that an expansion of nuclear power could reduce carbon emissions by X amount in X years — just repeated claims that “nuclear power is the answer.”

    So, nuclear advocates: where’s the beef?

    Comment by SecularAnimist — 12 Apr 2007 @ 11:14 AM

  179. > other life forms in the so-called “Dead Zone” around Chernobyl.
    > Far from being dead, it’s a nature preserve, and perhaps the
    > most ecologically healthy one in Eastern Europe.

    You’re jumping to a conclusion before the evidence is in; the work of tagging animals in and around the exclusion zone and tracking reproductive success is barely started. You can look this up in the science journals.

    Some species of birds somehow nest in the least radioactive areas (nobody knows how the can tell, yet).

    It’s quite possible the Exclusion Zone is a ‘Roach Motel’ for wildlife, they come there because it’s relatively free of human activity from all around. So far there’s no evidence that animals are reproducing successfully enough even to replace those that die there, let alone reproducing more successfully.

    When radioactive animals start showing up migrating away from there —- animals born in the Exclusion Zone that would have found all the niches occupied by other healthy wildlife, so they have to leave looking for living space — that would be proof that it’s an unusually healthy area for wildlife.

    This happens around less contaminated areas, for example the Oak Ridge Tennessee and Hanford Washington plants — they’re relatively healty for wildlife; it’s only what leaks out of burial sites that the animals pick up and concentrate.

    Seriously, when you make an assertion as though you knew it were a fact, support it with some evidence. When I check what you say is true, I find the opposite, and it discourages reliance on your postings.

    Remember, this is the _good_news about animal health:

    Transport of radioactive materials by jackrabbits on the Hanford Reservation…. 1975 –
    Abstract: A survey was conducted near waste disposal trenches … Radioactive feces, urine, soil, and vegetation were distributed in all directions….

    Radionuclide Concentrations in Nestling Raptors Near Nuclear Facilities
    TH Craig, DK Halford, OD Markham – Wilson Bulletin, 1979 – …. the same radionuclides were present in potential prey items collected near the radioactive leaching ponds and in samples of fecal material….

    Radionuclide export and elimination by coyotes at two radioactive waste disposal areas
    WJ Arthur III, OD Markham – Health Physics, 1982 –
    … Coyote fecal samples were collected near a radioactive waste leaching pond and a solid radioactive waste disposal facility and analyzed for radioactivity.

    Comment by Hank Roberts — 12 Apr 2007 @ 1:22 PM

  180. In reference to the coriolis force. I thought that the reason hurricanes go opposite of what we expect is that they occur at the boundary of two masses behaving as we would expect, they are like a gear between two other gears and will go in the opposite direction.

    To show students that the force is real, I modified the traditional physics experiment where a student sits in a rotating chair, is spun with weights in his outstretched hands, and the spin accelerates as he draws the weights into his body. I had them hold the weights out, but then lift them overhead, simulating northward motion on the earth’s surface. As the radius is decreased, the spin will accelerate.

    Comment by James Wasvary — 12 Apr 2007 @ 3:37 PM

  181. Re. 178

    I am not a big proponent of nuclear but what you said does not sit well with me.

    GHG will not be reduced if nuclear power is doubled due to demand growth keeping FF Power plants in use? If so what happens if nuclear does not double and the demand growth for power is made up with coal plants? Nuclear wouldn’t help there eh?

    Is that not the case with ANY type of power generation? If new power came from wind and solar and the extra power gained from them was used only to make up the power shortfall from increased demand, wouldn’t those coal plants still stay online?

    If new power is built at same rate as the demand icreases it does not matter what type of power generation it is. GHG would not be reduced, but they would not RISE due to the increased demand. (half the battle IMO.) The only way to decrease GHG is to build out power plants faster than increased demand for power.

    Comment by Jim — 12 Apr 2007 @ 4:38 PM

  182. James Wasvary,

    I am not implying in any way that you are wrong, I just can’t wrap my head around how the velocity of rotation increasing with decreasing radius relates to Coriolis deflection… I’ve been a dancer in a former life, so I know all too personally that if you want to keep spinning, you have to close in your arms, and you also have to keep your body vertically aligned (really straight); but how does that relate to being deflected to the right in the northern hemisphere, or left in the southern hemisphere. As I said, this is not a rhetorical question, rather a very honest one.

    Comment by Figen Mekik — 12 Apr 2007 @ 4:44 PM

  183. This may help:

    Comment by Hank Roberts — 12 Apr 2007 @ 5:10 PM

  184. Thanks Hank Roberts!!

    Comment by Figen Mekik — 12 Apr 2007 @ 5:40 PM

  185. Re: Jim’s comment at 4:38pm (currently #181):

    What you are saying is correct. If new non-fossil-fuel electrical generation is brought online to meet growth in electricity consumption, rather than to replace existing fossil fuel electrical generating plants, then at best it can slow the growth in GHG emissions from electrical generation. That’s valuable, but it would not actually reduce emissions from their current levels, which is what really needs to happen. And as you say, this applies to any and all non-fossil-fuel technologies, whether nuclear or solar or wind or hydropower or whatever.

    What’s needed to actually reduce carbon emissions from electricity generation, as opposed to slowing their growth, is to immediately stop building any more coal-fired power plants, and then start shutting down the existing coal-fired power plants.

    As I mentioned above, the American Solar Energy Society released a report at the end of January, which shows that full application of existing efficiency and renewable energy technologies have the potential to reduce US carbon emissions by “60 percent to 80 percent below todayâ��s levels by mid-century”. According to the ASES report, “Energy efficiency measures alone have the potential to keep our nationâ��s carbon emissions roughly constant over the next 24 years as our economy grows” and six renewable energy technologies (biofuels in the form of cellulosic ethanol to replace gasoline, and electric power production from wind, concentrating solar, roof-mounted photovoltaics, biomass, and geothermal) “have the potential to make the kind of deep cuts needed in our carbon emissions. Of the total carbon reductions possible, 57 percent are due to energy efficiency and 43 percent are from renewables.”

    Certainly those projections should be closely examined and skeptically criticized. But my point is that the ASES has put forward the basis for a plan to reduce US carbon emissions by 60 to 80 percent by 2030, which is in line with what many scientists believe is needed to keep CO2 concentrations below 450 ppm and prevent the worst climate change outcomes, using ONLY efficiency and clean renewables.

    So, where is a similar report from the nuclear industry or nuclear proponents, spelling out a realistic, plausible scenario for an expansion of nuclear power — of whatever size — and showing by how much and how soon that expansion will reduce carbon emissions? I haven’t seen it. All I see is hand waving and blanket assertions that “nuclear power is the answer” and “no one can be serious about reducing GHG emissions unless they support a huge expansion of nuclear power”.

    Comment by SecularAnimist — 12 Apr 2007 @ 5:49 PM

  186. Re #175: [Super! Then, of course, you'd have no problem moving there yourself, would you. Why not do that, and show how much you believe what you're saying?]

    Build some mountains there, provide decent high-speed internet service, and convince my employers that they really don’t need to see me in person every couple of weeks, and you’ve got a deal :-)

    But you’re resorting to “have you quit beating your wife” questions – as when the anti-nuclear activists ask if I’d want to live next to a nuclear plant. Of course if I answer honestly, I have to say no, because I don’t want to live next to an industrial facility of any sort. (I don’t even like living a couple miles from a geothermal plant.) Ask instead, if the only two choices are living next to a nuclear plant, and living next to a coal plant of the same size, which one I’d choose?

    So frame your question fairly: If a Chernobyl-type accident had happened in some place where I’d otherwise want to live, say Lake Tahoe, would I be willing to move there now, assuming of course that I was interested in moving at all? Then my answer is yes.

    Comment by James — 12 Apr 2007 @ 6:13 PM

  187. Re: Coriolis effect

    Am I missing something? We all agree the “Coriolis force” is not a force. But I submit that the “Coriolis deflection” is not a deflection at all. The video of a ball rolling on a rotating merry-go-round is a good illustration. The ball does not deflect; it merely appears to, because of the rotating frame of reference of the observer.

    It seems to me that objects do not deflect to the right in the northern hemisphere at all, they merely appear to. And it seems to me that the real reason for the rapid counterclockwise rotation of northern-hemisphere hurricanes is the conservation of angular momentum; as the already rotating air mass contracts, it must spin faster in order to conserve angular momentum.

    Comment by tamino — 12 Apr 2007 @ 6:15 PM

  188. Tamino, for sure. I’m with you 100% there as I was trying to make that point in my essay. But the more I read about this (Wikipedia included, but again I am in no way implying Wikipedia is the end all resource :) ) the more I am getting confused as people are saying there is Coriolis effect and there is Coriolis force. From my high school physics class I learned force must cause acceleration, and if things are changing direction of motion then, I guess, there is radial acceleration, so Coriolis is a force. But as you say, Tamino, nothing’s changing direction; it is just an apparent deflection. Please picture someone throwing up her hands. That’s me. If the moderators would help us out or anyone else, I’d be delighted.

    I know it seems if I write a piece about misconceptions, I should have all the answers. But I don’t and I am learning just as much and probably more than anyone. I would like to believe that everyone has much to learn, but maybe I am just making myself feel better.

    Comment by Figen Mekik — 12 Apr 2007 @ 6:27 PM

  189. Re #174: [Batteries have limited range and take hours to recharge...]

    The limited recharge rate isn’t really the problem there. Turn the problem around, and think about the amount of electric power that needs to flow to quickly recharge a battery.

    That’s one of the reasons I think plug-in hybrids are a much better solution. Most trips are within battery range, but when you need to go further, or need heat in cold weather, you use an engine and onboard fuel. This could even be a more efficient gas turbine or Stirling engine, since it wouldn’t need the torque and acceleration of IC engines.

    [In continental Europe there are already quite extensive networks of high-speed trains, but air travel is nonetheless growing fast.]

    I think that’s at least partly due to price. When jet fuel costs go up, that changes. Also, I’d thought that you really only had high-speed rail in France (with routes into Switzerland), and possibly Germany?

    [Electric cars don't have, and probably won't in the near future, the "performance" so beloved of petrolheads...]

    Do a search on Tesla :-)

    Comment by James — 12 Apr 2007 @ 6:32 PM

  190. Ok, and I have another question though my response to Tamino hasn’t been posted yet. When I am spinning, I certainly feel a lot of things like my center of gravity (if you are doing it perfectly it feels like your spinning axis is right in the middle of your center of gravity) and how even the slightest digression from being perfectly vertical causes tipping over in some direction.. But I thought these things had to do with one’s angular momentum. I don’t remember ever feeling being deflected any which way. Nor can I see any deflection in the mirror or on the video tape. So I thought Coriolis was a matter of scale: can’t see it in the toilet bowl, can’t see it in the dancer’s body. But maybe there are other factors here like a dancer has control over his/her body and does a lot of spotting (always looking at the same spot-the head spins last) in order to not lose balance and/or throw up on people. But again, I don’t get it. :)

    Comment by Figen Mekik — 12 Apr 2007 @ 6:40 PM

  191. Seems like you need to decide if you’re talking about
    spinning on an axis
    traversing a rotating plane
    traversing a rotating sphere
    and whether you’re using wheels or floating in the air

    Then stay in that same frame and understand how it works there without jumping out to a different physical system

    Comment by Hank Roberts — 12 Apr 2007 @ 7:00 PM

  192. Re #185: [But my point is that the ASES has put forward the basis for a plan to reduce US carbon emissions by 60 to 80 percent by 2030, which is in line with what many scientists believe is needed to keep CO2 concentrations below 450 ppm and prevent the worst climate change outcomes, using ONLY efficiency and clean renewables.]

    Then perhaps that’s our basic difference right there, when you say “below 450 ppm”. I think that’s utterly unacceptable: we must at least aim to get CO2 concentrations back within their historic range, below 300 ppm.

    Comment by James — 12 Apr 2007 @ 7:00 PM

  193. Re 187 Coriolis effect and hurricane rotation

    I am not a physicist or meteorologist, so I hope someone will correct me if I am mistaken here (esp. if I have misunderstood the question being debated):
    First the Coriolis effect -
    A person standing on the equator is rotating through space at roughly 1600 km/hr. That person fires a rocket toward the north pole and watches it fly away. Ignoring air resistance, the rocket moves north while continuing to rotate at 1600 km / hr, so it appears to the rocket launcher to be moving in a straight line north. Another person is standing at 45 degrees north latitude and rotating through space at roughly 800 km / hr; this person (who is very tall) watches the rocket as it flies north toward him and sees the rocket’s path deflected to the east; to that person, the rocket’s deflection is quite real. Likewise, the rightward (eastward) deflection of an ocean current heading north from the equator is quite real (relative to the sea floor), hence, it contributes to the clockwise flow of a subtropical ocean gyre.

    Now, the hurricane winds (Thanks to the USA Today’s The Weather Book) -
    Upper air winds flow toward a low pressure center, but the Coriolis effect forces the winds to right just as strongly; the result is the upper air wind flow around, but not into, the low pressure area.
    Near the ground, friction with the ground slows the wind and weakens the Coriolus effect (the magnitude of which depends on velocity of the moving object); the pressure gradient, however, remains the same. The pressure gradient is now stronger than the Coriolis effect and “pushes” the winds toward the low pressure center in a counterclockwise direction.

    Comment by Chuck Booth — 12 Apr 2007 @ 7:57 PM

  194. Chuck Booth,

    The first paragraph of your explanation was exactly what I thought and unfortunately taught, but Gavin told me I am wrong because the Coriolis effect has no latitudinal component. In other words, you would get the same Coriolis effect on a rotating cylinder, though latitudinal rotation rate changes become important for explaining westward intensification of subtropical gyres.

    Yep, I was stumped!! It keeps getting more and more confusing.

    [Response: Ummm... not quite. I was making a distinction between the beta effect (the change of f with latitude) and the simpler effect of being on a flat rotating plane (constant f). The beta effect is key for westward intensification of ocean currents (ie. why the Gulf Stream is much narrower and faster than currents on the other side of the basin), but isn't necessary for Coriolis effects. Those are seen very clearly on a merry-go-around (the top of the cylinder!). I apologise for having added to the confusion. - gavin]

    Comment by Figen Mekik — 12 Apr 2007 @ 9:01 PM

  195. Re 194 Figen,Yes, I’ve taught it that way, too, as that is how it was explained in an oceanography textbook many years ago. Perhaps I should stick to biology… Anyway, it occurred to me that if the rocket launcher and the observer were both standing on the prime meridian (for a convenient reference point on earth), they would remain on that meridian as they rotate through space, even though they are rotating at different velocities relative to a fixed observation point in space. So would the rocket’s path follow the prime meridian, or would it deviate to the east?

    Comment by Chuck Booth — 12 Apr 2007 @ 9:46 PM

  196. Re: Coriolis

    I worked out the equations of motion for a particle constrained to move on the surface of a sphere. If the particle undergoes geodesic motion (so that there are no forces), while the sphere is spinning, then from the point of view of an observer who rotates with the sphere, in the northern hemisphere there is always an apparent deflection to the right, proportional to both the spin rate and the sine of the latitude. In the southern hemisphere, there is always an apparent deflection to the left. This is the Coriolis effect.

    I guess the point is that this is true when the particle undergoes geodesic motion, so there are no forces and no deflection. There is only apparent deflection, so it seems to be incorrect to say “Coriolis force” or “Coriolis deflection,” only “Coriolis effect” strictly applies.

    Comment by tamino — 12 Apr 2007 @ 11:07 PM

  197. Coriolis, interesting to see inteligent people speculate about a subject outside their expertise. A little ironic to see misconseptions from scientists in a thread about laypeoples misconseptions about science.

    It might not be that strange that people have false ideas about science?

    The coriolis force exist in a rotating (accelerating) reference frame like the earth. This means that the coriolis force must be included for everything in the reference frame to follow F=ma.

    The coriolis force doesn’t exist in an inertial reference frame like space with a spinning earth in it (a reference frame fixed in space)

    The motions are independent of reference frame but the forces that must be included is different. The coriolis force is in same way not a real force but it acts on objects on the earth and must be included.

    Direction of rotation.

    The coriolis force is a force to the right in the northern hemisphere. Some people seems to want this to imply that everything also should rotate clockwise. This is not true as I have tried to explain above and that could be found in any meteorology book. The rotation direction depends an all forces involved not just the coriolis force. The theory for the rotation direction is well known and straight forward. There are no need to think that the results are strange or contradictory if looking at the whole phenomenon.

    Comment by Fredrik — 13 Apr 2007 @ 4:23 AM

  198. Rotation, sink, dustdevils.

    Tamino is correct about the conservation of angular momentum. Put some water in a sink and pull the plug results in rotation of the water. The speed is higher closer to the plug, this is a vortex. The reason for the vortex (rotation) is that the small rotation (vorticity) that already existed in the water got amplified due to conservation of angular moment, the water is “pulled” to the plug and the distanse to the center of rotation is shorter and the speed thus get higher. This happens all the time and can be seen in the sink or toilet. The important thing is the convergense of the water.

    A fun experiment is to pull the plug and look at the vortex, stir the water in the other direction and look at the new (hopefully) vortex in the other direction.

    This is going to happen even if a coriolis force doesn’t exist. The same phenomenon applies to the rotation of dust devils, tornados and huricanes

    The coriolis force is to small to give any difference in a normal sink or dustdevil or (probably) tornado but the birth of a hurricane is much slower and the coriolis force is important for a hurricane.

    Thus, the fast rotation seen in for example a sink is due to conservation of angular momentum and not due to the coriolis force. The coriolis force only came in for large slow system.

    Comment by Fredrik — 13 Apr 2007 @ 5:18 AM

  199. Someone has just refered me to this site as evidence supporting the Cosmic ray theory:

    This section; “IV Solar wind and Interplanetary Magnetic Field” mentions a decline in the cosmic ray flux over the last 4 minima of solar cycles, it also states:
    “(7) Close correlation was found between cosmic ray fluxes and atmospheric processes such as thundercloud electricity, lightning production, cloudiness coverage, and precipitation. The chain of solar-terrestrial relationship was established: solar activity – cosmic ray modulation – changes in the global electric properties of the atmosphere – changes in weather and climate”

    Can anyone tell me if this claim has value or relevance?


    Comment by Andrew Worth — 13 Apr 2007 @ 5:39 AM

  200. My favorite one is this.

    I used to work in a pharmaceutical manufacturing facility where we used to use dry ice in certain milling operations to reduce the heat generated.

    Well, we planned to make this particular product on a Friday, but the raw materials didn’t clear the lab, although the dry ice did arrive.

    So a technician decided he would put the dry ice in the refrigerator over the weekend.

    On Monday, the look of shock on his face was a sight to see, as he opened the box of dry ice and said “its gone !!! “

    Comment by Lake Michigan — 13 Apr 2007 @ 7:06 AM

  201. Re: #194

    According to my understanding, you do not get a Coriolis effect on a rotating cylinder. The equations of motion seem to back this up.

    Comment by tamino — 13 Apr 2007 @ 8:37 AM

  202. Re # 197
    [ interesting to see inteligent people speculate about a subject outside their expertise. ]

    Seems to me everyone does that every day – no one is an authority on everything, and most people (including scientists) are authorities on only a very small body of knowledge. And educated people are curious, and want to learn more, so they frequently delve further and further from their areas of expertise; in fact, research (and teaching) usually forces you to do this.

    [A little ironic to see misconseptions from scientists in a thread about laypeoples misconseptions about science.]

    Ironic perhaps, but honest. I don’t hide from my students the fact that I don’t know everything. The problem is, most teachers (including college professors) must teach topics outside their narrow fields of expertise (sometimes far outside). Anyone who has ever reviewed a draft version of a textbook knows the author, supposedly an authority on the subject, often makes glaring mistakes; unfortunately, some of those mistakes make it into the final version of the book and are taught and learned in the classroom (sometimes with additional mistakes introduced).

    [It might not be that strange that people have false ideas about science?]

    I don’t think anyone claimed it was strange – humorous at times, certainly frustrating at times, but not strange. The question is, how do educators (or educated people) go about correcting those misconceptions? Obviously, the first step is to correct their own misconceptions (and areas of ignorance), then go about figuring out how to do a better job of teaching the subject to someone else.

    And if topics such as the Coriolis effect are not clearly (or correctly) explained in textbooks, those of us who rely on those books for background knowledge will come away with misconceptions. I don’t have any real trouble understanding the mathematical explanation of the Coriolis effect – I can plug numbers into an equation and usually get the correct answer for the deflection. But, I don’t understand how the equation was derived. So, I’m still waiting for a clear and correct explanation (or analogy) that doesn’t rely on the math – that is what I need to help students understand the Coriolis effect. Simply giving them the equation doesn’t really educate them.

    By the way, the analogy of a moving ball (or line drawn) on a rotating disk following an arc is flawed in my mind: First, your hand (or the ball leaving your hand) is in fixed reference plane, whereas an ocean current or rocket heading north from the equator is in the rotating reference plane of the earth. Secondly, a record player turntable turns clockwise, whereas the earth (viewed from above) turns counterclockwise. If you rotate a globe counterclockwise while drawing a straight line from the equator to the north pole, the line will inscribe an arc deflected to the left, opposite that of the Coriolis effect.

    I’m open to a clear conceptual explanation or analogy of the Coriolis effect.

    Comment by Chuck Booth — 13 Apr 2007 @ 10:19 AM

  203. In defense of my questionable knowledge about the Coriolis effect, I quote here from a popular oceanography textbook, Ocean Circulation (Open University, Pergamon Press in association with The Open University, Milton Keynes, England, 1989):

    Chapter 1, page 7: “…When it leaves the launcher, the missile [fired northward from the equator] is moving eastwards at the same velocity as the Earth’s surface was well as moving northwards at its firing velocity. As the missile travels north, the Earth is turning eastward beneath it. Initially, because it has the same eastwards velocity as the surface of the Earth, the missle appears to travel in a straight line. However, the eastwards velocity at the surface of the Earth is greatest at the Equator and decreases towards the poles, so as the missle travels progressively northwards, the eastwards velocity of the Earth beneath it becomes less and less. As a result, in relation to the Earth, the missile is moving not only northwards but also eastwards, at a progressively greater rate… This apparent deflection of objects that are moving over the surface of the Earth without being frictionally bound to it – be they missiles, parcels f water or parcels of air- is explained in terms of an apparent force known as the Coriolis force. ”

    The book then presents a sidebar question about the Coriolis force for a hypothetical cylindrical Earth rotating about its axis. The answer at the back of the book is that “For the hypothetical cylindrical earth, the eastwards velocity of the surface would be the same whatever the distance from the poles, and so there would be no apparent deflection and no Coriolis force.”

    This is how I have been explaining the Coriolis effect to biology students for over 20 years – am I explaining it correctly? Or not?

    Comment by Chuck Booth — 13 Apr 2007 @ 10:45 AM

  204. Re 202: I couldn’t have said it better. I teach 3-4 courses per semester and though all are related to earth science the topics are wide and mixed. As for me personally, I hope it is clear to all readers that I am in no way implying I know everything, and if I were I would be laughably arrogant and wrong. Wasn’t it Socrates who said the more you learn, the more you realize how ignorant you are. And that’s the way it should be for a scientist and science teacher/professor. Everyone has misconceptions and ignorance. Everyone. The point is to be honest about it and learn from it and next time teach it better. That’s why I like RealClimate so much because thanks to the efforts of the moderators, scientific ideas are open to discussion without personal ridicule.

    Re 203: I am also desperately asking the same question, am I teaching this correctly? I am not all together convinced that your rocket example or the classic if we were flying in a plane problem is all that erroneous. I am probably really oversimplifying but I thought if you stick to a latitude, you don’t need to correct the route of your flight, but if you are travelling meridionally, you would have to correct your route and take into account the Coriolis effect. Is this right?

    Comment by Figen Mekik — 13 Apr 2007 @ 11:25 AM

  205. Re #198: [A fun experiment is to pull the plug and look at the vortex, stir the water in the other direction and look at the new (hopefully) vortex in the other direction.]

    Except that what happens is that within a minute or two, the new vortex will slow down, stop, and restart in the original direction. Why?

    Comment by James — 13 Apr 2007 @ 11:43 AM

  206. 203, I belive your book is correct. It doesn’t explain the coriolis force for east/west moment though.

    202, good post, I have some comments though but no time.

    Comment by Fredrik — 13 Apr 2007 @ 11:47 AM

  207. Re: Coriolis Effect

    This much is clear: understanding the Coriolis effect is not so simple!

    Re: #202

    I completely agree with your statements about self-knowledge of one’s own ignorance being essential for true advancement. But I disagree with your claim that if you draw a straight line (“straight” in the sense of being a geodesic on a sphere) from equator to north pole while the sphere rotates eastward underneath your pen, the arc will curve left; in fact it will curve to the right. Try it!

    I derived what I believe to be a rigorous mathematical formulation of the Coriolis effect on a rotating sphere, and I’ve posted it on my blog. I get the “correct” results — deflection to the right in the northern hemisphere, to the left in the southern, and all the right proportionality factors. It’s also clear that there is no force and no real deflection; it seems to me that only the term “Coriolis effect” is strictly applicable. And I get no Coriolis effect on a spinning cylinder.

    Comment by tamino — 13 Apr 2007 @ 12:24 PM

  208. #197
    In the original blog post by me and all the comments about Coriolis on this thread we keep saying deflection is to the right in the northern hemisphere, and to not confuse this with clockwise, counterclockwise, east or west. Let’s not keep repeating the same point.

    Comment by Figen Mekik — 13 Apr 2007 @ 12:43 PM

  209. Re 185.

    I don’t buy that we can make up so much with conservation alone. I am also not convinced that burning biofuels such as ethanol and biodiesel are carbon neutral. In the case of ethanol you are taking a food crop such as sugar and corn that are grown anyway and using it for fuel. Ethanol crops can and frequently do cause land use changes from forest to cropland and requires fertilization to grow it and energy to maintain and manufacter it. (Not to mention that corn ethanol produces less energy than is required to create it.) Biodiesel is also process dependent in whether you get more out than you put in and depends on the feedstock if it is carbon neutral.(needs to be algae based and based around a C02 producer which we have plenty of.) All require large amounts of water to manufacture. Unfortunatley the algae method for biodiesel is still in the prototype stage and they have yet to produce the fuel in volume. Ethanol/Biofuel have more to do with energy independence that GHG reduction. (Still a valuable goal though.)

    OTOH Of all the forms of solar power I find the algae biodiesel method to be the most promising for transportation.

    For conservation, I do not see that in the cards that humans will reduce power consumption. The fact that you sit on a computer connected to the Internet proves that. Certain economic and politcal objectives oppose energy conservation. (From simple ones to safety lighting to goals such as business persistance during disasters.)

    Comment by Jim — 13 Apr 2007 @ 1:15 PM

  210. Regarding Coriolis force and why it matters:

    The formation of the mid-latitude gyres in both hemispheres is also a function of the balance between the Coriolis acceleration and the pressure gradient. The result of wind blowing over water in the Northern Hemisphere is net (Ekman) transport of water to the right of the wind direction, thus when winds blow south along the California coast, the water is transported offshore and the result is strong upwelling that brings nutrients to the surface. See , as well as

    This is the point that Carl Wunsch has made; shutdown of the Gulf Stream is not going to happen due to a warming and freshening North Atlantic (but the formation of deep water in the Labrador sea is another issue).

    Comment by Ike Solem — 13 Apr 2007 @ 1:29 PM

  211. Re 207 Tamino…I did try it (drawing a straight line on a globe whose surface is rotating east) and I keep getting a deflection to the left. I first tried it while drinking a cup of coffee and preparing to eat a spherical chocolate truffle candy; I had no globe handy, so I used a Sharpie ink marker and drew a line on the foil wrapper while I rotated the truffle. The line wasn’t a smooth arc because the wrapper was crinkled, but it was deflected to the left. I tried it again at home using a large rubber ball – same thing. If, after all of this, I understand the Coriolis effect correctly (confirmed by your and Fredrik’s explanations) my hand would have to rotate east with the rotating globe in order to get a rightward deflection. Yes? In fact, my hand is in a fixed frame of reference relative to the rotating globe. A little thought experiment would seem to confirm this:

    Instead of drawing a continuous line on the rotating globe, I move the globe and my pen in discrete increments – each time I rotate the globe 10 degrees of longitude to the east, and move my pen 10 degrees of latitude north (in a straight line). Starting from the equator on the prime meridian, after three increments, my pen touches down at 30′ N, 30′ west. After three more increments, my pen touches down at 60′ north, 60′ west. Connecting the dots I get an arc deflected to the left.

    Re 210 Ike, Thanks for the link. I also teach, albeit in a very superficial manner, about the Ekman spiral. I must confess, I understand that (the progressive deflection of a current to the right with increasing depth, with the deepest component of the current moving, in theory, at 180 degrees relative to the surface water) even less than the Coriolis effect.

    Comment by Chuck Booth — 13 Apr 2007 @ 7:03 PM

  212. Re: #211 (Chuck Booth)

    On this we agree: following the procedure you outline, the line will intersect [0 deg.Lat, 0 deg.Lon] (the starting point), [10 deg.N, 10 deg.W], [20 deg.N, 20 deg.W], [30 deg.N, 30 deg.W], etc.

    That line is initially (at the equator) directed eastward. But this is not the Coriolis deflection, it’s just the initial direction of movement. Connect the dots, and the arc most assuredly *curves* to the right. The Coriolis deflection is the curvature of the line (to the right), not its initial direction (to the left).

    Comment by tamino — 13 Apr 2007 @ 9:28 PM

  213. Thanks Ike, that’s really helpful!

    Comment by Figen Mekik — 13 Apr 2007 @ 10:16 PM

  214. I know this is way too late, but way back at comment #21, Brian said

    They also say that the total mass after a chemical reaction is exactly the same as it is before. This is just wrong. Chemical reactions can be exothermic or endothermic, and convert some mass to heat or vice versa.

    Brian is just wrong, in chemical reactions the mass remains the same, the energy is stored in the molecules. With nuclear reactions some mass is converted to energy.

    This thread reminds me of The Jaywalk All-stars on Leno. The sad thing about it is Jay Leno claims that it is very easy to find people who can’t answer simple questions like name the vice president and when was the war of 1812. But even sadder, if he asked simple science questions the vast majority of people (my guess is 80-90%) would be clueless.

    Comment by Wang Dang — 13 Apr 2007 @ 10:33 PM

  215. Re #209: [I do not see that in the cards that humans will reduce power consumption. The fact that you sit on a computer connected to the Internet proves that.]

    I don’t see how that constitutes proof. Indeed, for me it’s just the opposite. I can sit at this computer and do useful work (at least my employers seem to think so, since they keep paying me :-)) without having to spend time and energy commuting. That saves maybe 5 gallons of gas per week. Then there are other savings: on-line banking & bill paying saves paper, stamps, and trips to the bank to deposit paper checks…

    Then think about the decreases in computer power consumption. Of course for years this was just less per megaflop or megabyte, masked by the fact that you kept getting more of them, but lately it’s becoming an absolute decrease. A few years ago I used a tower machine, with cooling fans that’d compete with a vacuum cleaner and a massive CRT display. Today I use a notebook & LCD display, and get better performance with much less power consumption.

    That same process, getting the same or better performance from less power, could be done in many fields, from electric lights to automobiles, if anyone cared enough to bother. That it mostly hasn’t is a reflection of the fact that, thanks to the offloading of environmental costs, energy has been so cheap that people have only bothered in special cases, such as notebooks and other mobile electronics.

    Comment by James — 13 Apr 2007 @ 11:31 PM

  216. Re # 214 [Chemical reactions can be exothermic or endothermic, and convert some mass to heat or vice versa.]

    You might want to rethink that statement.

    Comment by Chuck Booth — 14 Apr 2007 @ 9:20 AM

  217. Re: #214 (Wang Dang)

    Brian is just wrong, in chemical reactions the mass remains the same, the energy is stored in the molecules. With nuclear reactions some mass is converted to energy.

    No, Brian is right. If the chemical reaction causes the emission of radiation, the mass of the chemicals left behind is reduced proportional to the energy radiated away, according to E=mc^2 — just as with nuclear reactions.

    Comment by tamino — 14 Apr 2007 @ 9:46 AM

  218. Re: Correction to #212 (Tamino)

    I mistakenly said, “That line is initially (at the equator) directed eastward.” I should have said, “That line is initially (at the equator) directed northwest.”

    Comment by tamino — 14 Apr 2007 @ 11:47 AM

  219. Re 214: [...when was the war of 1812.]

    Sometimes those simple questions can be deceptive, though. So when was the War of 1812? Now if you give the simple answer, “1812, of course”, you’d be only about 20% right. It started in June of 1812, and lasted until January/February of 1815. (The ending date varies because its best-known engagement, the Battle of New Orleans, was actually fought after the peace treaty had been signed.) See? Not such a simple question, was it?

    Comment by James — 14 Apr 2007 @ 12:15 PM

  220. Re#216
    Thanks Chuck, I forgot to put the quote around the paragraph from Brian’s statement in #21. The sentence you quoted is the one from Brian that I was trying to correct.

    “This, my leige, is how we know the earth to be banana-shaped.”

    Comment by Wang Dang — 14 Apr 2007 @ 1:03 PM

  221. James,

    Actually computer consumption has been increasing. Case in point. CPU power consumption for say a P75 was around 8-9 Watts and required modest cooling, to processors that consume from 65 to 130 Watts on current buld processes. (There are more effiecent CPUs but they are geared to mobile and embedded applications.) Granted they get more performance per watt, the power consumption has still increased significantly. (Even your laptop uses alot more power than a model of 5-10 years ago even with greater performance per watt.) In most cases the increased power effiency in new processes are used to drive increased performance per watt, not to lower absulute power usage. (Excpetions are only mobile electronics.) Video coprocessors are even worse with current state of the art video subsystems consuming 200Watts or more. Most folks that use PCs alot also leave the things on 24/7. (Folding or SETI @Home) In any case you end up with more load on the electric grid due to PCs that require more power.

    PCs are also a poor measure of effiecency as silicon fabrication is certainly not grean , and is very energy,resource, and manpower intensive to manufacture. (Takes 10-100′s of man-years to design a CPU!) Lastly all of those obselete PCs that are in the trash are not that great either.

    I was mainly speaking of the Internet, which is not power effiecient at all. It requires PoPs all over the place, each with regulated and backup environment and power. (Average power for a medium size core router is 8000Watts with heat output of 8000BTU/hr and the biggest ones for big hubs can consume 13.2 Kwatts per 7 foot rack! Again you don’t just have one there are layers to good network design!) In addition most datacenter’s are under power consumption crunches as the outgrow their electricity and UPS capacities regularly due to increased power density from hosted servers. This server you use for this website is not all that cheap on power you know.(Average 1U server consumes 350-500Watts and average Datacenters have 100s to 1000s of them to be profitable) Neither for that matter is the clusters everyone uses to run simulations as they are racks of a bunch of 1U servers all of which require backup power and regulated environment on backup power.

    Lastly Internet bandwidth demand growth (Internet growth about an order of mangitude every 2-3 years.) is much higher than power demand growth and will not level off, and in effect it drives a portion electricty demand growth. (Increased bandwidth capacity -> more equipment -> more fiber laid in the ground -> more cooling for COs, DCs and PoPs -> more backup UPS power -> more electric power demand -> more oil burned to lay fiber and power electronics) Increased demand is driven by all of us tapping on our keyboards, watching video, bit torrent, etc.etc.

    Yes, I baited you some as we have sparred about this in the past. :)

    Your job is unusual in that you get to stay put and get paid. (How nice!) I have to go all over the place to do my job even though I “telecommute” to work. They certainly would not pay me if I sat in one place all of the time! (I live in Florida and the company is in Maryland.)

    I said I don’t think conservation will achieve the goals that were put forth in a previous post of 50% of a 60% reduction in carbon footprint in the US. It will do some but not near that much and this example is just one of the reasons why. We like the conveniance and comforts provided by abundant power and will not want to do without them and folks are always thinking up new ways to get electricity to do more and more tasks that we don’t want to do. (TV remote sound familiar?)

    Comment by Jim — 14 Apr 2007 @ 1:10 PM

  222. Re Brian’s comment about mass and energy:

    What about the vice versa part?

    Comment by Chuck Booth — 14 Apr 2007 @ 4:52 PM

  223. There is some truth to what you say, especially if you take the points in isolation, and not as part of a whole. You get several trends working in different directions: higher efficiency because more performance per watt, yet more power demand because more people are buying computers. More internet bandwidth using more power because more people are finding more things to do on-line, but a lot of those things replacing more energy-intensive alternatives. (What’s the energy cost of say downloading a movie vs going to a video rental store vs going to an actual movie theater?) It’d take someone more knowledgeable than me to say where all those factors balance out at any given time, but I think trends are towards lower total per capita consumption.

    You do need to remember that we’re still in the midst of an ongoing process. At first the emphasis was on geting the damn things to work reliably, then increasing performance regardless of energy cost. Now pure performance is giving way to power efficiency. Remember when the main selling point in computer ads was clock speed? Nowadays that’s often relegated to the fine print. Limiting power consumption has become a selling point in the commercial world.

    As for conservation, a lot depends on how much incentive there is. When there’s no apparent cost associated with leaving your PC on 24/7 (or leaving outside lights on all the time, or whatever), of course a lot of people are going to do just that. Raise the perception of cost, though, and that changes behavior.

    Comment by James — 14 Apr 2007 @ 4:53 PM

  224. Re # 212, 218 Tamino,
    Correction noted, but you’ve still lost me. I fail to see how a line connecting a series of ink marks on a globe that start at 0 lat, 0 long. and end at, say, 60 deg. N, 60 deg. W, can be described as curving to the right. If an imaginary person knowing nothing about the Coriolis effect had been standing on the prime meridan at 40 deg. N (Mediterranean coast of Spain?) and learned there was a giant pen heading north that would crush him, he would no doubt have been pleasantly surprised to find that the path of the killer pen seemed to be deflected to the west, out into the North Atlantic. (And had he known about the Coriolis effect, he might have expected the giant pen to veer east and touch down somewhere in Turkey; but, then, he likely wasn’t aware that the pen was in a fixed, external reference frame, and not rotating with the globe.)

    So, where have I gone wrong?

    Comment by Chuck Booth — 14 Apr 2007 @ 7:17 PM

  225. Actually everything I said was true.

    Current state of the art for CPUs is going multi-core packaging or silicon die (As an example AMD does multi-cores per die, where Intel does multi-cores per die and then multi-die per package.) with individual cores driving towards power effieciency with more performance realized with multiple cores per socket. While it is true that some higher performance individual cores are getting into the 25 – 50 watt range. With the current rage of quad core and soon 8 core chips, you get power ranges still in the 100 to 200 watt range for CPU processing. (Although the performance increases per watt.)

    You need to remember that it is ALWAYS an ongoing process that never stands still! (As in all science with the expetion that digital technology grows by orders of magnitude.) The only reason that the clock speed race was called off was the fact that no one could continue to ramp the clock speed (In volume) due to the current silicon processes having high switching leakage current and high static leakage current that was inhibiting clock speed increase past the magic 3 to 4 Ghz barrier. That “barrier” is still hard to get through today and the chip companies are always trying to one up the other with performance increases so they tried a different tack with the above mentioned multi-core and each individual core getting more IPC (wider paths which also has limits.)

    As far as downloading a movie or driving to watch one, that has to do with individual taste. I like going to the theater for the experience. If I paid for a “movie room” in my home it still would not be the same. Cost can regulate behavior to some degree but there will always be folks that buy everything online (Like you.) and folks like me who like to go get it. Just a matter of taste.

    Comment by Jim — 14 Apr 2007 @ 10:42 PM

  226. Re #217
    tamino, thank you for the correction. I was wrong, but only because my chemistry professors lied to me many years ago.

    I apologize to Brian.

    Comment by Wang Dang — 15 Apr 2007 @ 1:39 AM

  227. Re #225, Although overall modern CPU’s are moving to ever smaller die sizes (0.65 and 0.45 micron are the current targets attained) and more cores on the same die etc I believe that low power versions are coming base around TDP (thermal envelope) of around 35 to 85 Watts. Under load they will obviously consume more but far less than previous CPU’s have.

    Issues relating to graphic cards and more than one of them worry me as these technologies are now finding their way into games consoles to. Recently a 1 KW power supply was released for PC’s in order to power quad graphic cards configurations. I have a 550 Watt one in my machine.

    How many playstation 3′s will be sold world wide and how many high definition LCD/Plasma TV’s ? A large LCD TC consumes over 300 Watt of power, 5x more than a 32″ CRT TV.

    it is a worry.

    Comment by pete best — 15 Apr 2007 @ 7:53 AM

  228. Re: #224 (Chuck Booth)

    I hope the Spaniard would hear from reliable news reports that the giant pen wasn’t heading north at all. Earthbound observers will testify that it was never heading north, it left the equator heading northwest. Space-based observers may think it’s heading north, but they’ll also say that the Spaniard is heading east, so the two are not on a collision course.

    Now let the pen go all the way from equator to pole. From the viewpoint of an earthbound observer it starts out northwest, which is most definitely not in the direction of the pole. But its path curves to the right — the more so the further north it gets — as it must in order to reach the pole.

    The apparent deflection is only due to the observer’s point of view; space-based observers (in an inertial frame) see the pen go straight (in a geodesic sense) from equator to pole.

    Of course the best way to see this is to find a globe with latitude/longitude lines, put dots on the points [0,0], [10N,10W], [20N,20W], etc. all the way to the north pole, and connect the dots.

    Comment by tamino — 15 Apr 2007 @ 8:39 AM

  229. Re #225: [With the current rage of quad core and soon 8 core chips, you get power ranges still in the 100 to 200 watt range for CPU processing.]

    While on the other hand you see more and more people who, like me, realize that they don’t need multi-core CPUs for what they do, and would rather have portability & longer battery life. The multi-core CPUs and high-end graphics processors go to a small minority.

    [The only reason that the clock speed race was called off was the fact that no one could continue to ramp the clock speed...]

    Not entirely. There’s also the fact that a lot of that clock speed was wasted due to memory bandwidth limitations, so your 3 GHz CPU was often stalling on memory 3 clocks out of 4. Consider that the BlueGene supercomputers were designed with 700 MHz CPUs for just these reasons, memory bandwidth & power consumption.

    [As far as downloading a movie or driving to watch one, that has to do with individual taste.]

    It’s individual taste only if one has both options. How many more people would be driving to movies if they couldn’t download or rent videos? Frankly, I have no idea. What I do know is that having such options makes it possible to arrange life so as to use much less energy. And at least in my case, save time and improve perceived quality of life too.

    Comment by James — 15 Apr 2007 @ 10:58 AM

  230. Re 229.

    Actually you are wrong.
    Multi-core CPU’s are now maintsream components in both desktop and laptop computers. Also 40 to 50 Watt video subsystems are also mainstream for desktops with laptops having 10 to 20 watt accelerators. (The only exception being intel integrated graphics which are very crappy and are only good for surfing, no games or opengl rendering works and use about 5-10 watts max.) Core2 Duo and Turion X2 processors are definitly the “sweet spot” for selling chips. Quad cores are supposed to hit 2008. I suppose you could get a Via C7 or some other ultraportable which only uses a watt or so to pound out your email though. (Good luck using that with power hungry apps though.) In any case it is what is sold the most, not what you think you like. I also value portability as I have to travel all around to do my job, and my corporate provided cheapie “mainstream” IBM laptop has a core2 duo in it and gets about 8 hours with two battery packs which is good enough for me.

    Mainstream in called “mainstream” for the express purpose as that is where the most volume and sales dollars are. (Like the guy said above think about all of those big LCD TVs, xbox 360′s and PS3s!) If what is sold draws more power in absolute terms than what was sold before that constitutes increased power demand even though the computers are much more powerful and have more MIPS/Watt.

    You are also mixing diferent types of applications, from PCs to supercomputers which have radically different design philosphies. IBM picked an intial 700Mhz clock speed for blue gene as it a seriously multi-core device using altivec instructions for vector math which is easily parrelizable BTW. They needed a certain Giga/Flop per core target figure that maximized performance/watt and they got it with power pc440 at 700Mhz. It has 1024 CPUs (2048 cores) with a NUMA memory acrchitecture which totaly renders irrelevant memory bottlenecks as each processor module has 4MB L3 cache and each quad of cores has a path to 512MB of local dram. (That causes memory bandwidth to scale linearly per each quad of cpu cores, total GB/sec = X You can bet to compete their next “blue gene” will have vastly greater power, memory bandwidth, power draw, cpu clockspeed, and number of CPUs.

    Just for a counterpoint the Cray Redstorm uses 2,000 to 120,000 cores (96 per cabinet) single/double/quad core AMD opteron cpus. Running from 1.6 to 3Ghz, with each CPU core providing 10 to 12GB of memory bandwidth, scaling from 960GB/sec memory bandwidth/cabinet. The sandia red storm uses 2MW of power for 10,000 2.0Ghz CPUs for 40Tflops, 55TB/s memeory bandwidth, with an eye to triple that performance near term.

    In any case modern CPU designs are increasingly effective at hiding the latency to main memory by using large caches, seperate on die connections to memeory (AMD), doubling memory bus width , prefetching data to cache before it is needed, doing out of order reads on the memory bus and busting writes to maximize BW utilization, etc. etc.

    Also the clock speed war was killed becuase Intel could not ramp the Pentium 4 design beyond 3-4 Ghz in volume without turning them into good space heaters. (They still had a good crack at it though. The P4 design was intended to reach 10 to 20 Ghz and ran into process leakage problems not a desire to lower power requirements. Same with AMD, once they could no longer scale the clockspeeds of their designs at will they were the first to emphasize performance/watt and power consumption as a means to compete as they were beaten by intel on the clock speed front. (just now getting to 3 Ghz.)

    Your last paragraph fine. If staying at home increases your quality of life, well more power to you. If I am not mistaken you leave in the moutains a good ways from town? (You said that in a post somewhere.) I don’t and it would not take near as much time and energy for me to go out as it would for you.
    I have already said your job is definitly not the norm as most employers want to see your face, or move you all around (like me) in order to pay you!

    Comment by Jim — 15 Apr 2007 @ 12:53 PM

  231. [[Correction noted, but you've still lost me. I fail to see how a line connecting a series of ink marks on a globe that start at 0 lat, 0 long. and end at, say, 60 deg. N, 60 deg. W, can be described as curving to the right. ]]

    If you’re facing west.

    Comment by Barton Paul Levenson — 15 Apr 2007 @ 2:25 PM

  232. Jim wrote in #221: “I said I don’t think conservation will achieve the goals that were put forth in a previous post of 50% of a 60% reduction in carbon footprint in the US.”

    Jim, did you read the section of the freely downloadable American Solar Energy Society report that projected the carbon emission reductions that could be achieved with application of existing efficiency technologies?

    If you did read it, can you cite specific flaws in, or offer specific rebuttals to, its projections?

    If you did not read it, why not? Are you so confident in your own beliefs and assumptions that you already know that it must be wrong, so there is no need to read it?

    Comment by SecularAnimist — 15 Apr 2007 @ 4:21 PM

  233. Re 232.

    No I haven’t read it. I am going too as soon as I can, and quit trying to bait me into saying something snotty. That kind of language only works on the unwashed after all. In any case projections are not reality. (For exmaple, look at the projected power savings for the new DST in the US that saved nothing.)

    I will delve into electronics a bit as I can’t help myself as I am an EE after all. :) In one of my past jobs (I have went from the electric power industry to, lightweight ASIC/VHDL/Verilog, to heavy circuit design, to something a lot easier, Internet backbone architect, and I got to keep my hair :) ). I designed portable eqiupment for where there was profitablity in the extra time and effort required to shave milliwatts out of every part of the system design. For the control eqiupment and everyday stuff, all that was desired was for the equipment to perform reliably (Case in point, TTL is still used everywhere) , and the “management” would not sanction the extra time and effort. (And material costs as well as low power ICs, and basic components come with a premium as they had to do the same thing for the IC as we have to do with the circuit.) That extra effort is not a small undertaking, it is a significant portion of overall design costs, and will not be performed without some expectation of a return on the investment. Lastly, in some cases a reduction in power is not possible if the driving design goal is a performance target. (ie. MIPS in a certain amount of floor space.)

    But I do know this, us science folks don’t know much about the people we design things for. Lots of toys, gadgets and specificly software and OS are written or designed by technical people for technical people, not for the mass of folks that are simply wired different. (Vista or Linux ring a bell?) I am also going by the current facts of the real power demand growth and power shortfalls we have already, and a proliferation of ever more power hungry devices to use that power. (eg. entertainment equipment such as xbox360, ps3, and PCs.) As long as people do not wish to do a menial task they will design a new machine to perform it for them. That is just basic human nature and there is ample proof all around you as we are all guilty of it. (Cars, Dishwashers, calculators, vacuum cleaners, washing machines, remote controls, etc.etc.)


    Comment by Jim — 15 Apr 2007 @ 7:10 PM

  234. Re # 232 I’m looking at a globe (actually, a large rubber ball) with a series of ink marks heading north and west (up and left) from the ball’s equator. Although my pen moved straight north as it laid down the line of dots, an observer on my “globe” would see the pen heading northwest, as Tamino pointed out. By my estimation, the pen will eventually touch down at 90 deg. north, 90 deg. west (I need a real globe with lat. and long. lines to verify this).
    By the way, in case this point has gotten lost, I originally used this example to point out what I consider to be a flawed analogy for demonstrating the Coriolis effect (likewise, inscribing a line on a record rotating clockwise on a record turntable is also a flawed analogy, I think- I have seen both used in books or on websites). A proper analogy should account for the fact that the “pen” must rotate “east” in the same frame of reference as the earth, not reside in a fixed (intertial) frame of reference as the earth rotates under it.
    I’ll have to go out and buy a globe and check this out – it’s hard guessing at lat. and long. lines on a green rubber ball.

    Comment by Chuck Booth — 15 Apr 2007 @ 7:35 PM

  235. Re #230: [Actually you are wrong.]

    Well, it happens, but about what, exactly?

    [Multi-core CPU's are now maintsream components in both desktop and laptop computers.]

    Did I say otherwise? What I said is that lots of people find they don’t need the most powerful machine available, like many people I work with, who’ve gone to notebooks from desktop machines. As for relative power consumption, given the lower level of heat & fan noise, I have to think the laptop is using much less power. Humm… OK, doing a “cat /proc/acpi/battery/BATT0/info” tells me that each battery pack in my machine has a design capacity of 59.2 Watt-hours. I can work about 2-3 hours per pack, so I must be using about 20-30 watts on average, no? Since my last tower machine had IIRC a 350 watt power supply, it would seem I’ve cut my power consumption considerably. Factor in the difference between 20″ CRT and LCD, too.

    [Like the guy said above think about all of those big LCD TVs...]

    Fine, but compare their power consumption to an older TV (even going back to vacuum tubes), or an LCD screen with a CRT. Once again, the technology works both ways: cut power going to solid state & LCD, increase it going to bigger screens. What’s the net effect?

    You’re also wrong on a lot of details of the BlueGene architecture (about half the code I write these days is targeted to BlueGene), and I’m pretty sure you’ll find the next generation using even less power per CPU than the current one.

    [I have already said your job is definitly not the norm as most employers want to see your face, or move you all around (like me) in order to pay you!]

    You miss my point there, though. Add up all the miles not driven by the current telecommuting population, and I bet it more than cancels out the increase in energy use in internet infrastructure. As for you and your employer, sure, they may want to see your face now, but how badly will they want to go on seeing it when doing so puts them over their mandatory CO2 targets?

    Once again, there are two factors at work. One is the possibility of achieving various energy reductions, the other is giving people the incentive to use them. Given the first, people may or may not choose to use it. Without it, they can’t.

    Comment by James — 15 Apr 2007 @ 10:53 PM

  236. lets do that. My argument is that the net affect of all of these advances is power consumption growth, not a net reduction, you have yet to say anything that refutes that.

    [[Multi-core CPU's are now maintsream components in both desktop and laptop computers.]

    [Did I say otherwise? What I said is that lots of people find they don't need the most powerful machine available, like many people I work with, who've gone to notebooks from desktop machines]]

    In a sense yes. Stating that simply going to notebooks from desktops saves power. The answer is it depends. Not to long ago my PC had a 120Watt power supply, now laptops have 120Watt power supplies. Yet current mainstream desktops use about 300Watts. So if you switch from a new computer to an new laptop then yes you save power. However switching from an older computer to a new laptop the power savings are not so clear. In any case successive iterations of the SAME devices do not use less power which was the main thrust of my argument.

    My point being mainstream, is that these multi-core machines are not the fastest available, they are what is on special at walmart/bestbuy and as such get sold the most, hence power consumption grows.

    [Once again, the technology works both ways: cut power going to solid state & LCD, increase it going to bigger screens. What's the net effect?]

    The net effect is to use more power. Some examples:

    Let’s use LANL blue gene verus Sandia RedStorm verus ENIAC as a good example:

    Blue Gene Power input 26.7KW max 7 Kw Min per rack
    with a requirement of 8 ton cooling per rack. (8 tons is approx 30Kw power draw.) So each rack is requiring 56.7 KW max power. LANL had a final buildout of 64 cabinets with a total aggregate power draw of 56.4Kw x 64 = 3.609 MW. Red Storm at Sandia uses 24 cabinets each that draw 22Kw Max with similar cooling requirements for an aggregate of approx 3MW. ENIAC pulled 150Kwatts with no AC units.(All power was Peak power draw.) Granted the computing power of the newer systems utterly dwarfs ENIAC, my point has been made.
    Even when we recover effieciecy in indivdual components those are more than made up with an increased performance target for each successive generation.

    Another example. My 6 year old 32 CRT Inch Zenith HDTV pulled 231 Watts, My samsung 42 inch HDTV monitor pulls 228 Watts. (A wash if you ask me.) Both are average models that costed about a 1200-1300 bucks new.

    Another example

    PS2 drew about 40-45 watts, PS3 draws around 200Watts, with total peak power 380Watts. Xbox360 uses around 160Watts, with 500 Watts peak. (I know that they never get near peak for consumer systems but gotta put them in there for accuracy.)

    I have made my point using easily verifiable facts. (Except my tvs of course.) Performance/watt always increases yet the net affect is a steady increase in power draw as now the designers use more and more of that performance. (In almost all electronics that is true.) For mobiles old laptops drew less than new ones do. Get an old one and see for yourself. The current trends are clear, newer devices do more or are more powerful, have more performance/watt, and draw more power than the previous generation. Thus creating greater power demand. Going back to tubes is irrelevant as that stuff died away in the early 70s, and as AGW folks everywhere say it is the las 30 years that show the warming trend, so it is the last 30 years of silicon electronics that also matters.

    [You're also wrong on a lot of details of the BlueGene architecture]

    Really? Even though I got those details from IBM?
    What details did I get wrong?

    See for yourself:

    One Data sheet from IBM

    And the watered down one on wikipedia

    [I'm pretty sure you'll find the next generation using even less power per CPU than the current one.]
    Maybe if that is there design goal than yes. If IBM decides to use Power 5 or Power 6 CPUs in Blue Gene, then you are wrong. And as of right now they have to do something as their competition can do 64bit CPUs and they use 32 bit CPUs which means power 5, PowerPC 970, or Power 6. If they use Cell, it still pulls more power than the current PPC 440s in there. Make no mistake, without altivec for vector math programs, those 440′s would not be in there as their other performance areas are very weak.(Integer ops)

    Just becuase you write code doesn’t mean squat. I have written assembly and high level code for a lot of stuff too, and if you code to the metal with power assembly language then yes, you SHOULD know what you are talking about, but if you code in fortran or some other high level language, you have an abstraction layer that does the details for you and you are writing a logic algorithm, not moving bits or understanding (Or needing to understand) the physical hardware that well. Lots of programmers don’t know what mov aex bex means!

    You totally missed my point. Writing computer code is about the only thing you can do in isolation from your employer. If you have to interact with people in any meaningful way, you can’t do that effectively with telecommuting. (Nothing beats a look in the eye and a good handshake!) In any case the telecommuting popluation is very very very very small.

    Comment by Jim — 16 Apr 2007 @ 12:41 AM

  237. 205, “Except that what happens is that within a minute or two, the new vortex will slow down, stop, and restart in the original direction. Why?”

    This doesn’t happens for me when I have tried the experiment. Did it happen for you?

    Comment by Fredrik — 16 Apr 2007 @ 2:50 AM

  238. 207, “This much is clear: understanding the Coriolis effect is not so simple!”

    I would say that it is easy to derive the coriolis acceleration mathematicaly. Easier than you have done in my opinion.

    To intutivility understand the details of it is not that simple but I think the explaination in Chuck’s book is clear and simple enough. It is a quantiative reasoning though.

    ” It’s also clear that there is no force and no real deflection; it seems to me that only the term “Coriolis effect” is strictly applicable. And I get no Coriolis effect on a spinning cylinder.”

    Yes, the force doesn’t exist if we look at the earth from space, but do we do that? We live on the earth and thus rotate togheter with it and the force exist in our world. You feel the centrifugal force when you sit on a merry go round. It is nothing imaginary with it. I have performed the throwing ball on a rotation disk experiment as seen in a movie above and the coriolis force definitely existed in my world then.

    Comment by Fredrik — 16 Apr 2007 @ 3:02 AM

  239. Why the missconceptions and errors? I belive the main reason is that people try to explain difficult subjects for people without adequate knoweledge, often a lack of mathematical skill. Trying to explain a phenomena in an intuative way without using math in short. This is very good if someone managed to do it but it often fail to explain the phenomena and it sometimes lead to errors.

    Aerodynamics and flight theory is a good example of this happens. It exist a well known theory but it involves difficult concepts and mathematics. People have try to explain why an airplane fly without the mathematics and the result is often a disaster like for example the equal transit time claim and claims that either of Bernuelli or Newton is correct about flight when the truths is that they actually are the same theory.

    You can found a lot of books claiming that they explain flight in the correct best way but they often include large errors and incorrect logic.

    The reason is that the real theory is difficult so we try to explain it instead.

    The coriolis is simular though actually easier. People dont understand the math and try to explain it without math and the result is not always good.

    Comment by Fredrik — 16 Apr 2007 @ 6:27 AM

  240. Re: #238 (Frederick)

    I would say that it is easy to derive the coriolis acceleration mathematicaly. Easier than you have done in my opinion.

    I’m sure you’ve seen far simpler derivations of the Coriolis effect in 3-D space, or on a flat 2-D surface. But the complication of movement constrained to the surface of a sphere adds a few layers of complexity to the “traditional” derivation.

    Certainly the mathematical framework in which I chose to work is far more difficult. But if that framework is already familiar then the equations of motion simply “fall right out” of the formalism. So I’d agree that the mathematical framework is far more complicated, but once that’s mastered the derivation of the answer to this problem is far simpler. That seems to me to be a common theme in physics; as the math gets more advanced, the physical derivation gets simpler.

    Still, I admit I used mathematics not familiar to many people, so my derivation isn’t very accessible. I was just trying to get the correct answer.

    ” It’s also clear that there is no force and no real deflection; it seems to me that only the term “Coriolis effect” is strictly applicable. And I get no Coriolis effect on a spinning cylinder.”

    Yes, the force doesn’t exist if we look at the earth from space, but do we do that? We live on the earth and thus rotate togheter with it and the force exist in our world. You feel the centrifugal force when you sit on a merry go round. It is nothing imaginary with it. I have performed the throwing ball on a rotation disk experiment as seen in a movie above and the coriolis force definitely existed in my world then.

    I disagree. You don’t feel a centrifugal force at all; what you feel is the centripetal force required to make you orbit around the center of the merry-go-round rather than move in a straight line.

    As for the ball thrown by a rotating observer, your perception of the Coriolis “force” is entirely imaginary. The word “force” has a very precise meaning: it produces acceleration in an inertial frame. If we allow any reference frame at all to define force, then I can make the “force” on any object, at any moment, anything I want it to be.

    Re: #239

    I agree that attempting to explain essentially mathematical phenomena in non-mathematical terms can be a source of misconceptions and errors. Attempts to explain the theory of relativity without mathematics illustrate the extreme difficulty of doing so.

    But I would emphasize that another source is the imprecise use of terminology. Words like “force” and “acceleration” have very precise meaning in physics, but when we misuse them to describe apparent forces and accelerations which are really only due to the reference frame of the observer, it can lead to a great deal of misconception and error.

    Comment by tamino — 16 Apr 2007 @ 10:41 AM

  241. Re #236: [Not to long ago my PC had a 120Watt power supply, now laptops have 120Watt power supplies.]

    Yet can run for several hours off a battery holding 60-80 Wh? I think maybe you’re confusing peak draw with average power consumption. Sure, if I test a fairly large simulation on a laptop, the CPU will kick up its clock speed, the cooling fans will come on, and I’ll be drawing a lot of power. The thing is, I don’t do that all that often. Most of the time I’m just looking at the screen, or typing, and the machine is drawing a small fraction of its max power. This wasn’t true of older machines: it was the need for power conservation in mobile computing that created that ability, which then moves into other machines.

    [What details did I get wrong?]

    To start with: [it a seriously multi-core device using altivec instructions for vector math which is easily parrelizable BTW.]

    The BlueGene has no more vector math capability than the Pentium/AMD processor in your PC. The FPUs in each core can process two 64-bit doubles simultaneously (Intel can do 2 doubles or 4 floats), but whether that capability is usable depends on the code.

    [It has 1024 CPUs (2048 cores)...]

    Depends on the size of the machine. The one I mostly use has 4K CPUs, BG/W I think is 56K, the LLNL machine a full 128K.

    [...with a NUMA memory acrchitecture which totaly renders irrelevant memory bottlenecks as each processor module has 4MB L3 cache and each quad of cores has a path to 512MB of local dram.]

    Not at all. BlueGene is essentially a message-passing architecture, with each CPU having its own memory. It’s a bit more complicated, in that CPUs are organized in pairs, each pair having access to 1 GByte. In coprocessor mode, one CPU does computation, the other handles communication tasks, sharing the memory. In the other mode, each CPU has access to half the memory, and handles its own computations.

    Except for the communication mode, the memory access and its bottlenecks are just like those in a single PC – in fact, you can look at BG as just a big, optimized Beowulf cluster. That and power consumption are the reasons it runs a 700 MHz clock. It’s also the reason why, if you do serious profiling & performance analysis on a large problem (too big to fit into cache) you’ll find that no matter how fast your CPU, execution speed is pretty much limited by memory access times.

    [Lots of programmers don't know what mov aex bex means!]

    I guess I’m one of them. Try MOV EAX, EBX :-)

    Comment by James — 16 Apr 2007 @ 11:45 AM

  242. “But the complication of movement constrained to the surface of a sphere adds a few layers of complexity to the “traditional” derivation.”

    It is just to constrain the equation to the surface. No large step. I am familiar with your notation. I was talking more to most of the people that probably dont understand your notation. “where gamma are the Christoffel symbols for the space” is going to make 99.9 % of the population look as question marks.

    About if the forces exist or not. You feel a force an a merry go round or in an airplane doing a loop. It must be included if you want to make calculations in the acceleration frame as is often done. But all this is about semantics because we both talk about the completely same thing.

    “The word “force” has a very precise meaning: it produces acceleration in an inertial frame. If we allow any reference frame at all to define force, then I can make the “force” on any object, at any moment, anything I want it to be.”

    I have to disagree here. The word force is used for the coriolis and centrifugal force in mechanics. The [tex]C(dot(q)q)q [tex] term in lagrangian mechanics is always (as I have seen) called centrifugal and coriolis forces. I am working with wind turbines and people talk about centrifugal forces in the blade all the time.

    We live on earth and most people are never going to leave the earth. So why go outside the reference frame of the eart to perform calculations?

    test [tex]$C(dot(q)q)q $[tex]

    Comment by Fredrik — 16 Apr 2007 @ 11:46 AM


    Good article about the subject.

    Comment by Fredrik — 16 Apr 2007 @ 12:04 PM

  244. How do you use tex notation in posts?

    Comment by Fredrik — 16 Apr 2007 @ 12:28 PM

  245. [mov aex bex]

    That was at 1 in the morning after a very long day! it would work though just got to get creative with register renaming!

    [The BlueGene has no more vector math capability than the Pentium/AMD processor in your PC. The FPUs in each core can process two 64-bit doubles simultaneously (Intel can do 2 doubles or 4 floats), but whether that capability is usable depends on the code.]

    Not true. The original vanilla 440 does not even have an FPU, Blue gene CPUs possess a special FPU grafted onto the CPU core via the APU interface(FPU2) that is specialized to handle math and SIMD to accelerate througput. Altivec is just an implementation of SIMD I was trying not confuse anyone by using a well known trade-name. I don’t write code for altivec or FPU math for blue gene so I don’t know if those instructions are the same.

    In any case, yes Intel/AMD also have SIMD (SSE/2), the register scarcity and stack based FPU archtectures hamper their performance considerably, whereas the PowerPC does not have to lug around the x86 ISA and as such its performance in FPU calcs is much greater.

    The 1024 cpu figure was per rack as the machine size varies with budget. It was still not wrong.

    Comment by Jim — 16 Apr 2007 @ 3:01 PM

  246. So much wisdom and such an obvious flaw. Of course proximity to the sun can’t cause seasons otherwise north and south would have summer at the same time. You can force water to rotate the other way going down a drain buy swirling it with your hand befor pulling the plug so no cosmic force is behind that one. However the little rant about humid air implies that ice is lighter than air since you say water vapor is lighter than air and water expands when it freezes therefore ice would be the lightest of all. A water molecule is lighter than an oxygen molecule or nitrogen or CO2. However humid air consists of dry air PLUS water vapor and since air is very rare fitting the water molecules in between the various air molecules is no problem. The two combined in a given volume must outweigh the individual components. In much the same way a gallon of sea water is heavier than a gallon of fresh water simply because it has more “stuff” in a given volume. Finally the students expressed the sentiment that humid air “feels” heavy and it does. This is tied more to density than weight. Oil is lighter than water but because of its’ much higher viscosity it feels much thicker than water and the fact that oil floats would seem counter-intuitive. This reminds me of a global warming denier I heard who said it was impossible for melting ice to raise sea levels since a glass full of ice didn’t over-flow when the ice melted. He ignored the fact the melting ice is currently in glaciers and ice caps on land and would flow TO the oceans when it melted.

    Comment by Russ Ashe — 16 Apr 2007 @ 5:31 PM

  247. If we take two air masses with the same number of molecules in each, a dry air sample and a “wet” air sample, then because the water molecule is light compared to N2 and O2, the wet air sample will have less weight.

    Comment by Figen Mekik — 16 Apr 2007 @ 6:09 PM

  248. Russ, you talk with such an authority. The problem is that you are incorrect. Humid air at a given pressure is lighter compared to dry air at the same pressure. You can read it in any meteorology book.

    Comment by Fredrik — 17 Apr 2007 @ 3:35 AM

  249. Re #245: [That was at 1 in the morning after a very long day!]

    I thought as much :-) I have days like that too.

    [...Blue gene CPUs possess a special FPU grafted onto the CPU core via the APU interface(FPU2) that is specialized to handle math and SIMD to accelerate througput.]

    I don’t know how special it is. I had the impression it was pretty much a stock design from the PPC family, but that sort of thing isn’t really my area of expertise. To get back at least to first-order off-topicness, though, what I do know (’cause I’ve written & profiled a lot of code) is that both suffer from memory bandwidth issues. Most of the time, you can’t pull in data from memory fast enough to keep even a 1 GHz CPU busy.

    The processor speed thing is like cars, in a way. Sure, you may have a turbocharged 440 Hemi (or whatever, I’m not up on the lingo) under your hood, and maybe it has a top end of 200 mph or so, but just how often do you get a chance to go that fast?

    Comment by James — 17 Apr 2007 @ 12:21 PM

  250. It depends on the workload. If you write programs that use large datasets (like you do.) then yes the proccessor is DRAM BW limited. If the dataset is small enough to fit in cache or it is a typical branching application, then the cache architectures of current CPUs effectively can and do hide the latency of main memory and the acute scarcity of memory BW. Modern cache’s get a 90 to 95% hit ratio and they are striving for more. Just can’t cache 1GB yet though! :)

    The PowerPC440 used in blue gene has a relatively slow FSB to main memory (Espcially compared with today’s most modern proccessors.) It ain’t bad at all, it is 128bit 5.5GB/sec bus. IBM covers this up using a tiered cache architecture that culimunates in a really good 4MB L3 edram cache (30 cycle latency to l2/l1 cache, 22GB/s.) However with datasets larger than 4MB the BW becomes constrained by the 5.5GB main memory bus to that node’s DRAM bank. Here is a good block diagram of the CPUs per node.

    Modern consumer processors have DRAM memory buses that are also 128 bits wide with 10-12 GB/Sec throughput which helps but does not solve bw issues. Progress is frustratingly slow on this front I agree. BTW that night was hell, my 15 month old son had a middle ear infection at the time. Whew! :)

    Comment by Jim — 17 Apr 2007 @ 7:42 PM

  251. Forgot to mention. The BlueGene FPU is faily normal for a modern FPU but IBM did a very good job on it to get those FLOP/Mhz numbers out of it. :) If you read the design history there was an existing bolt-on FPU for 440s (440s did not have an integrated FPU.) that had one pipeline and could handle 1 Double. The FPU2 was designed to double the FPU1 performance while being both binary compatible and in a similar power footprint.

    Comment by Jim — 17 Apr 2007 @ 8:02 PM

  252. Re 217 (re 21)Tamino: “The mass of the chemicals left behind is reduced proportional to the energy radiated away…”

    So, what is the source of that lost mass (or what gains mass in an endothermic reaction)? Does some very tiny subatomic particle disintegrate (or materialize from energy gained in an endothermic reaction)?

    Comment by Chuck Booth — 18 Apr 2007 @ 11:04 PM

  253. For a balanced view on the matter of mass loss in chemical reactions, I would point you to Wikipedia first and then the discussions here and here (in the first instance at least). Here endeth my off-topic contribution ;-)

    Comment by P. Lewis — 19 Apr 2007 @ 4:30 AM

  254. Re: #252 (Chuck Booth)

    Does some very tiny subatomic particle disintegrate (or materialize from energy gained in an endothermic reaction)?

    No, when the potential (or any other) energy of a system changes, and the energy enters or escapes the system, that energy change contributes to the total mass of the system. So even if the number and type of particles is unchanged, the mass changes. In most chemical reactions, the mass change is so tiny that it’s nearly impossible to measure.

    The references given by P. Lewis (#253) are quite good on this topic.

    Comment by tamino — 19 Apr 2007 @ 10:29 AM

  255. This is the best thing that I have ever read and I actually understood it considering that i’m fifteen years of age from Tennessee and it is
    great to know somebody actually knows what the heck they are talking about. Well, anyway about the ozone layer and the hole that is incorporated is something i’m concerned with, but lately there has been an increase in ozone that has dramatically inclimented a change in the atmosphere itself if you’ve been watching the hole in the atmosphere above antarctica you would notice the ozone is coming back, but to my next topic of global warming. This is a very serious problem and we have been experiencing the effects of it. This winter we had alot of weird weather including weeks of extreme cold and weeks of fluential warmth. Now we have a certain problem called big storm syndrome like Two single storm cells fuseing to become one. If anybody has a clue or idea just post it cause this is really an awesome topic to discuss probably one of the best ones.

    Comment by Jared — 27 Apr 2007 @ 11:25 AM

  256. Ok just one more comment. I actually took the time to read all the entries and i’m rather intrigued at the funny things you people have tried such as the pen and globe thing that when you draw a straight line on a globe it will always reflect unless you draw backwards while spinning the object the opposite way which in this case differentiate the polarity of the north and southern poles. Like you people said the coriolis effect. In which case the object going around the earth in the opposite direction is most likely to be traveling twice as fast as upon entering the atmosphere, so would the object go further. One more thing if we slung shot something around the earth using the pull of gravity could we make in some case a slingshot effect. Just a question, Truly I think it would work and we could travel farther in outer space if we could generate this effect it is said we do not lose our momentum on non-gravatational areas such as space and time.

    Thank you for listening if i’m wrong correct and do so quickly, Because i like messing with science and the fundamentals of space and time also known as 3rd and 4th demensions

    Comment by Jared — 27 Apr 2007 @ 11:40 AM

  257. Hi Jared,

    Thanks for posting comments. I am glad you liked our post. Yes the ozone hole is definitely on the mend. But the recent freaky weather we’ve been having is just weather and not necessarily an indication of a climatic trend in one way or the other. I will have to respond to your comments about the coriolis effect on another day because I am about to leave on a trip for the weekend. Cheers,

    Comment by Figen Mekik — 27 Apr 2007 @ 4:56 PM

  258. >slingshot
    Yes, gravity can be used either to speed up or slow down a spacecraft passing a planet. One discussion here:

    “… The limit is how fast you can loop around
    a planet without dipping into its atmosphere too deeply (let alone
    crashing into it). Some NASA missions have repeatedly skimed the
    upper atmospheres of Venus and the Earth in their maneuvers …”

    Comment by Hank Roberts — 27 Apr 2007 @ 5:35 PM

  259. [[One more thing if we slung shot something around the earth using the pull of gravity could we make in some case a slingshot effect.]]

    In fact I think NASA actually does launch west-to-east to take advantage of the Earth’s rotation. It’s not a huge advantage, but it’s a noticeable one.

    Comment by Barton Paul Levenson — 29 Apr 2007 @ 2:50 PM

  260. Just a note to say thanks again to all who contributed with commnets. This has been very educational for me. :)

    Comment by Figen Mekik — 2 May 2007 @ 10:33 AM

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