RealClimate logo


Ozon Deliği Sızdırıyor ve Bunun Gibi Başka Hikayeler

Filed under: — group @ 5 April 2007 - (English)

Yazan ve Ingilizce’den çeviren Figen MekikGrand Valley State University

“Ama Figen, nemli hava ağır geliyor!” dedi öğrencilerim, neredeyse hepsi bir ağızdan. Gerçekten çok değerli bir an. Belki uzun yıllardan beri yanlış bildikleri bir şey yüzeye çıktı: su buharı kuru havadan daha ağırdır. Hemen hesap makinalarımızı ve periyotlar cetvelimizi çıkarttık ve H2O’nun moleküler ağırlığını hesaplayarak, N2 ve O2’ninkilerle (havakürenin büyük bir kısmı) kıyasladık. Büyük bir yanlış olguyu düzelttim diye sevinirken gerisini göremedim.

Meğerse bu ağır nemli hava fikrinin hemen altında daha yanlış başka düşünceler de varmış. Bir öğrencim sordu: “su buharıyla sıvı suyun formülü aynı mı?” Hangi halde olursa olsun suyun formülünün hep H2O olduğunu duyunca çok şaşırdı. Hatta buzun bile! “Bilimde herşeyi basit tutmaya çalışırız” dedim. Bir iki kız güldü “hiç de bile!”

Sonra başka bir öğrencim itiraf etti ki hep su buharlaşınca H2 ve O2’ye bölündüğünü zannedermiş. Bu durumda nemli hava daha ağır oluyor. Başka bir tanesi cevap verdi “Öyle olur mu ya.. Su buharı, sıvı hale dönüşünce moleküller büyür. Bu yüzden sıvı su, buhardan ağırdır.” Hemen buharlaşma ve sıvılaşmanın moleküler dinamiği üzerinde uzun bir tartışmaya giriştik. Ayrıca bildiklerini zannettikleri bir şey ile (su buharı ağırdır) televizyondaki hava durumu yayınlarından bildikleri bir başka şeyi (alçak basınç yağmur demek) karşılaştırınca, bu iki fikir arasındaki çelişki onları “bildiklerini” tekrar düşünmeye ve düzeltmeye mecbur etti. Bir saatin sonunda “Çok tuhaf, meğerse nemli hava yükselirmiş, kim bilebilirdi ki,” demeye başladılar.

Bunlar gibi çok yaygın olan bir kaç başka yanlış kanı da şunlar:
[1] Mevsimler, dünyanın düzenli olarak güneşe yakınlaşmasından ve uzaklaşmasından meydana gelir. Bu yanlış bilginin muhtemel sebepleri (a) içgüdüsel olarak mantıklı oluşu, ve (b) ders kitaplarında dünyanın yörüngesindeki elips şeklinin çok abartılması; o kadar ki bu yanlış düşünce makul oluyor. Ancak maalesef bu çok yaygın bir yanlış kanı, taa ana okulundan lise fizik öğretmenlerine kadar. Aklı çok karışmış bir genç adam bana şunu demişti: “Ilk okul 3. sınıf öğretmenim mevsimlerin, dünyanın ekseninin yörünge düzlemine göre dik olmayışından kaynaklandığını; kuzey yarımkürede kışken, güney yarımkürede yaz olduğunu söylemişti. Oysa lisedeki yerbilimleri öğretmenim dünya güneşe yakınken yaz olur, uzakken kış olur dedi. Yani yazın dünyanın her yeri sıcaktır. Şimdi siz diyorsunuz ki ilk mektep öğretmenim haklıymış. Sonra, güneş lekelerindeki faaliyet artışı sebebiyle yerküremiz ısınıyor diyorlar. Eğer güneş mevsimleri yaratacak kadar etkiliyse (hangi sebeple olursa olsun), bu düşünce bana mantıklı geliyor. Ama siz diyorsunuz ki küresel ısınmanın esas sebebi insanların havaküreye ekledikleri CO2. Size nasıl güvenebilirim?”

Haklı! Eğitimindeki çelişkileri düzeltmek çok zor. Ve böyle durumlarda ben doktoralı bir iklim bilimciyim demenin ne pek bir değeri ne de etkisi oluyor. Onun için, haklı olduğunu kabul ettikten sonra bir ay boyunca dersi, öğrencilerle deneyler yapmaya ve veri ve hata payı analizlerine adadik. O dönem kıyısal jeolojiyi işleyecek vakit kalmadı ama yinede değdi bence.

[2] Ozon tabakasındaki delik ve hava kirliliği (aerosol adı verilen küçük parçacıklara varıncaya kadar) küresel ısınmaya sebep oluyor. Bir önceki gibi bu da çok yaygın ve düzeltilmesi güç bir yanlış kanı. Medya ve pek çok ilkokul ve lise öğretmeni tarafından da böyle anlatılıyor bu konu. Belki de bunun sebeplerinden biri dünyaya güneşten ışınım değil ısı ulastığının zannedilmesi. Yani ozon tabakası gezegenimizi hem güneşin zararlı ışınlarından hem de ısısından koruyor. Ama delik olduğuna göre altına fazla ısı sızıyor ve sonra alt tabakalarda hapis kalıyor bu ısı, ve böylece küresel ısınma oluyor. Biliyorum, eyvah! Bu yanlış düşünceyi düzeltmek için ben öğrencilere diyorum ki güneş tabii ki çok sıcak ama aynı zamanda da çok uzak, ve dünya ile güneş arasında büyük bir boşluk var. Dünyamıza güneş ısınımın bir kısmı kızılötesi (ısı) olarak gelse de, güneş o kadar sıcak ki ışınımının sadece az bir kısmı kızılötesi, büyük bir kısmı ise görülebilir ışık ve morötesi ışınlar halinde bize ulaşıyor. (Burada hissedilebilir ısı ile ışınım arasındaki farkı belirtmek için küçük bir düzeltme yaptık. Kusura bakmayın.)

Ancak, ozon azalması ile küresel ısınma ilişkilidir kavramı o kadar da yanlış değil. Daha önce de burada tartışıldığı gibi (Ozon Azalması ve Küresel Isınma), ilk CFC gazları ve hatta ozonun ta kendisi aslında kuvvetli birer sera gazıdır. Buna ek olarak, küresel ısınmayla oluşan stratosferdeki soğuma, orada ozon tabakasının incelişini hızlandırıyor. Ve hatta CFC’lerin yerine kullanılan gazların dahi sera gazı olma potansiyeli olduğu saptandı. AMA, ozon tabakasındaki incelme (ozon tabakasındaki delik), küresel ısınmaya sebep olmuyor.

Öğrencilerle bu tartışmamız er ya da geç havadaki aerosolleri de kapsamaya başlıyor. (Aerosols: the Last Frontier). Aerosoller her ne kadar güneşten gelen ışınları emip dağıtarak biraz ısınmaya sebep olsalar da, daha büyük etkileri soğuma doğrultusunda oluyor. Çünkü bulut oluşumunu olumlu yönde etkileyip gezegenimizin albedosunu (ışık yansıtma özelliğini) arttırıyorlar.

[3] Sera etkisi ve küresel ısınma aynı şeydir. Bu da eyvah! Belki bu yanlış olgunun kökünde çok zaman ders anlatılırken sera etkisi ile küresel ısınma konuları birlikte işleniyor. Öğrencilere açıkça belirtilmeli ki sera etkisi olmasaydı, gezegenemizin ortalama sıcaklığı 30 derece C daha az olduğu gibi, gece-gündüz arasında aşırı ısı farkı olurdu. Pek yaşam için uygun bir iklim değil. Ancak insan eliyle meydana gelen küresel ısınma, sanayi devriminden bu yana atmosferdeki sera gazlarının, özellikle CO2’nin, artmasındandır. Gezegenimizin geçmişinde buzulçağı ve buzulçağı-arası dönemlerdeki iklim değişimleri hem güneş faaliyetleri hem de sera gazlarındaki doğal artma ve azalmalar ile açıklanabiliyor elbette. Ancak son bir kaç onyıldır yaşadığımız küresel ısınma mıktarını açıklamak için muhakkak insanların havaküreye eklediği CO2’yi hesaba katmak gerek (mesela, IPCC 4th Assessment SPM ve Avery and Singer: Unstoppable Hot Air).

[4] Kuzey ve güney yarımkürede sifon çekildiğinde tuvaletteki su birbirinden farklı yönde döner. Bu aslında pedagojik olarak kullanışlı bir yanlış kanı. Tamamıyla asılsız olmasına rağmen, temelindeki esas doğru ve sadece bir ölçek meselesi bu. Bunu dedikten sonra eklemeliyim ki Koriolis etkisi öğrencileri en çok zorlayan konuların başını çekiyor. Öğrenciler genellikle sağa doğru yönelmeyle, doğuya doğru yönelmeyi biribirine karıştırıyor. Ayrıca konuya bir boyut daha ekleyip dikey yöndeki hareketi de ele alınca (tropik fırtınalar gibi), öğrenciler için bu iyice içinden çıkılamaz bir konu haline geliyor. Bu yüzden doğu-batı, saat yönünde veya aksinde gibi deyimleri hiç kullanmamaya özen gösteriyorum. Bunu, öğrencilerim dijital olamayan klasik saatleri tanımayacak kadar genç olduklarından yapmıyorum. Bu konu uzerinde durmamın sebebi uydu fotoğraflarına baktığımızda, fırtınaların kuzey yarımkürede saat yönünün tersine döndüğünü (yani sola) görmemizdir. Öğrencilerin açıkça “sola dönüş” olarak görebildiği bu olguyu inkar etmek mümkün değil. Ama açıklamamızı basit tutar, “Kuzey yarımkürede hareket eden cisimler, hareketleri doğrultusundan sağa doğru kayarlar” dersek anlaşılması biraz kolaylaşıyor. Ama yine de çok zor bir konu bu. Burada bir başka zorluk da Koriolis etkisinin bazan bir güç olarak algılanması. Henüz fizik dersi almamış öğrenciler bir güçle etkinin arasindaki farkı bilemiyorlar.

Belki de şimdi içinizden diyorsunuz ki “batı Michigan’daki bir okulda böyle olabilir, ama daha prestijli üniversitelerde muhakkak ki öğrenciler daha bilgilidir.” Ah keşke böyle olsa. Kendine Göre bir Kainat (A Private Universe) adlı video, Harvard mezunlarının mevsimlerin oluşma sebebi ve ayın evrelerinin nedeni hakkında ne kadar cahil olduğunu sergiliyor. Bu yanlış kanıların yaygınlığının sebebi, bunları öğrencilerde tespit etmenin çok zor oluşu. Öğrenciler, öğretmenin duymak istediği cevabı vermekte, ve doğru kelimeleri kullanmakta usta, ama çoğu zaman kavramları iyi anlamış değiller. Dokuz yıldır üniversitede eğitmenlik yaptıktan sonra öğrencilerimi “akıllarına geleni” söylemeye teşfik etmeyi öğrendim. Böylece, farkına varmadan bana yanlış bilgilerini belirtirler de, ben de düzeltirim diye umuyorum.

Bunu sadece Amerikalıların sorunu olarak görebilirsiniz belki çünkü son zamanlarda Amerikan eğitim sistemi çok eleştirilir oldu. Ama bu da maalesef doğru değil. Internette bir iki çabuk tarama şu sonucları verdi: Yunanlı anaokulu öğretmenleri ozon deliği ile küresel ısnmayı birbirine karıştırıyor. Yunanlı ilkokul öğretmenleri ozon deliğinin iklim değişikliğine sebep olduğunu zannediyor. Avusturalyalı üniversiteli gençler ozon deliğinin büyük bir kısmının Avusturalya uzerinde olduğuna inandıkları gibi, cilt kanserindeki artışları da buna bağlıyorlar. Israil’de orta okul öğrencileri küresel su devinimindeki belli şeyleri iyi bilselerde, bu büyük döngünün okyanusta başlayıp yeraltı suyunda bittiğini zannediyorlar. Ve bazı Türk fizik öğretmenleri ayın doğup battığına inamadığı gibi, bazı Türk öğretmen adayları ise yaz aylarında dünyanın güneşe daha yakın olduğunu zannediyorlar.

Peki ya siz? Bu küçük sınavcıkla kendinizi deneyin bakalım. ;) (Sınavı yenilemek üzere şimdilik kaldırdılar galiba)

Fakat bu sınavda bazı sözcük ve anlatım hataları var sanırım. Ayrıca bazı sorular çok detaylı veya belirsiz veya Chicago-merkezli. Ama hakkında ne düşündüğünüzü bilmek isterim.

Peki bu yanlış kanılar nereden çıkıyor? Kişisel deneyimlerin ve içgüdüsel anlayısların büyük payı var bu yanlış algılamaların gelişmesinde ve okul boyunca pekişmesinde. Size çok tatlı bir kısa hikaye anlatmak istiyorum. Bir grup 4. sınıf öğrencisinin ısı konusunu öğrenirken ki maceraları. Çok bilinçli bir öğretmenleri var, ve ısı konusunu onlara bir soru yönelterek açıyor: “Bana sıcak bir şey örneği verin.” Öğretmen güneş veya ocak gibi yanıtlar beklerken küçükler palto, şapka, hırka deyiveriyorlar. Bir tanesi “halılar fena sıcak” diyor. Öğretmen “ama ben hırkanı tutunca sıcak gelmiyor” deyince “ohhh, bu bir zaman meselesi, zamanla 200 derece bile olur!” diyor öğrenciler. Kusur bulabilir misiniz? Hayatlarının dokuz kışı soğuk Massachusetts de geçmiş ve anne-babalar ve öğretmenler hep “sıcaklarını” giy yavrum demişler.

Bu örneğin gösterdiği gibi sorunun bir bölümü dilden kaynaklanıyor. “Sıcak giyim” sanki ısı yayan bir hırka izlenimi bırakıyor; “sera gazı” sanki seralar gaz içeriğinden dolayı sıcakmış intibası veriyor; güneşin doğusu-batısı sanki güneş gök yüzünde hareket ediyormuş anlamını veriyor ama aslında dönen dünya; ve “görecelik kuramı” sanki her şey görecelidir der gibi oluyor ama kuramın esası ışık hızının değişmezliğine dayanır.

4. sınıfımıza geri dönelim, bakalım öğretmenimiz bu durumla nasıl başa çıkacak. Tabii ki “Çocuklar öyle şey olur mu, sıcak olan sizsiniz” diyebilir. Bu çok zaman kazandıracak ve daha çok konu işlemeyi mümkünleştirecek bir tutum olur muhakkak. Ama bu öğretmen çok tecrübeli ve onları hiç kırmıyor. “Peki, herkes yarın evinden sıcak bir şey getirsin” diyor. Ertesi gün şapkalar, atkılar, paltolar ve hatta bir kuş tüyü uyku tulumu geliyor. Öğretmen her parçanın içine bir termometre koyuyor ve gecenin geçmesini bekliyorlar ki zamanla herşeyin içi kızışsın diye. Öğrenciler uyku tulumunun 400 derece Fahrehayt olacağından eminler. Ertesi gün pür heves gelip termometrelerine bakıyorlar. 68 derece F! (18 derece C). Hepsi çok şaşırıyor. Ama kani oldular mı? Kesinlikle hayır! Dokuz yıllık kişisel deneyimlerinden öyle hemen vazgeçerler mi? “Içlerine soğuk hava girdi” diyor bir küçük kız. “Ben arabada camları kapatıp oturunca çok terliyorum. Elbiselerimizi saklamamız lazım,” diyor. Hemen her şey çekmecelere, dolaplara dolduruluyor, her parçanın içinde termometresi var tabii. Bir gece daha geçiyor. Sabah koşa koşa gelip bir bakıyorlar, yine 68 derece. Ama bir tanesininki 69 derece. Hepsi alkışlıyor. Bari doğru yönde bir gelişme var diye herhalde. Bu böyle bir kaç gece devam ediyor. Sonunda ciddi tereddütler doğmaya başlıyor. Öğretmen diyor ki “giysilerin sıcak olduğuna inananlar bu tarafa geçsin” ve solu gösteriyor. “Kendilerinin sıcak olup giysileri ısıttığını düsüneneler sağa geçsin” diyor. Hemen hemen hepsi sağa gidiyor ama üç tane inatçı sola gidiyor. Hep inkarcılar olacaktır herhalde! Ama ne olursa olsun bu çocuklar ısıdan çok daha önemli iki şey öğrendi: bilimsel sorgulamanın esasını ve bazan gerçeklerin hissedildiği gibi olmadığını.

Peki yanlış kanılar anlayısı engelleyen unsurlar mı yoksa pedagojik aletler mi? Bu her öğretmen’in tarzı ve yapısına göre değişecektir. Ama önemli olan [1] yanlış kanıları sorgulamak, [2] yanlış olduklarını deneyler vasıtasıyla göstermek (eğer öğrenciler deneyleri düzenlerse daha da iyi), [3] bu soruların yanıtlarını ararken pek çok hipotez üretmek ve [4] onları tek tek deneylerle sınamak ve [5] ne olursa olsun hiç bir öğrencinin ortaya çıkmış bir yanlış kanıyla sınıfı terketmemesini temin etmek. Ve belki daha da etkili olacak bir yol, devlet bilim kuruluşlarının öğretmenleri eğitmek için bol miktarda para, zaman ve çaba harcamaları olacaktır.

Açıklama: Ben eğitim psikoloğu değilim. Üniversite’de profesör ve deniz/iklim bilimcisiyim. GVSU’nun Jeoloji bölümünde son derece zengin bir eğitimcilik hayatı yaşamaktayım. Ancak burada anlattığım hikayeler ve atıflar, taa Orta Doğu Teknik Üniversitesinde 1991 yıllında mastır yapmaya başladığım sıradan beri sürekli ve tekrarli bir şekilde duyduğum yanlış kanılara dayanmaktadır. Bu yanlış kanılar da herhangi bir tek öğrencime ait olmayıp, yayınlanmış 7000 fazla yanlış bilgi üzerine dayandırılmıştır.


260 Responses to “Ozon Deliği Sızdırıyor ve Bunun Gibi Başka Hikayeler”

  1. 1
    J.C.H says:

    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.)

  2. 2
    Paul Dietz says:

    I’m reminded of the story about heavy boots.

  3. 3
    Nick says:

    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

  4. 4
    Daniel C. Goodwin says:

    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.

  5. 5
    Figen Mekik says:

    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..

  6. 6
    P.C.G. says:

    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).

  7. 7
    tico89 says:

    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.

  8. 8
    Randolph Fritz says:

    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.

  9. 9
    Eli Rabett says:

    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.

  10. 10
    Marcus says:

    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)

  11. 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.

    Cheers

    martin

  12. 12
    Janis Mara says:

    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
    http://www.ecotality.com

  13. 13
    tamino says:

    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”!

  14. 14
    Marcus says:

    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.

  15. 15
    Ross O'Connell says:

    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.

  16. 16
    Hank Roberts says:

    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!”

    http://www.jstor.org/jstor/gifcvtdir/dm000276/03050270/dm995515/99p0137x_l.1.gif?config=jstor&K=user@user_response/41pEH0QJKn4HmqNr.0/40/4kkjMAE0/303050270.dm995515.99p0137x.0/PEk51zK0Qm8cuZRoMhuUC

    Seed germination and moonlight:

    http://links.jstor.org/sici?sici=0012-9658%28196410%2945%3A4%3C884%3AAPERBS%3E2.0.CO%3B2-V&size=SMALL

  17. 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.

  18. 18
    Aaron Lewis says:

    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.

  19. 19
    Tavita says:

    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.

    http://homepage.psy.utexas.edu/homepage/class/Psy394N/Woolley/9%20Mar%2021%20Reasoning%20&%20Problem%20Solving/Vosniadou%20Brewer%201992.pdf

  20. 20
    Steve Latham says:

    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.

  21. 21
    Brian says:

    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.

  22. 22
    NeilS says:

    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?

  23. 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.

  24. 24
    Luke Silburn says:

    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?

    Regards
    Luke

  25. 25
    Bolo says:

    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?”

  26. 26
  27. 27
    g.dungworth says:

    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.

  28. 28
    stuart says:

    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.

  29. 29
    Ray Ladbury says:

    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.”

  30. 30
    Phillip Shaw says:

    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.

    Regards

  31. 31
    makarov says:

    “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.

  32. 32
    Figen Mekik says:

    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!

  33. 33
    Pat says:

    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.

  34. 34
    Ike Solem says:

    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.
    OR
    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.

  35. 35
    Danny Bee says:

    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?

  36. 36
    Robin Johnson says:

    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!

  37. 37
    Thomas Folz-Donahue says:

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

  38. 38
    Peter P says:

    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.

  39. 39
    Steve Reynolds says:

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

  40. 40
    Edward Greisch says:

    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.

  41. 41
    Edward Greisch says:

    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”.

  42. 42
    Kaoten says:

    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.

  43. 43
    Greg Simpson says:

    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.

  44. 44
    John Ryan says:

    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]

  45. 45
    Figen Mekik says:

    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!! :)

  46. 46
    Taylor says:

    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!”

  47. 47
    Nigel Williams says:

    and if you want some interesting stuff about our sun, dip into
    http://thesurfaceofthesun.com/blog.htm
    Kinda makes you think..

  48. 48
    Ray Ladbury says:

    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.

  49. 49
    Bruce Scott says:

    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.

    ciao,
    Bruce

  50. 50
    Nigel Williams says:

    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.


Switch to our mobile site