The invention of Pangaea. And why the Appalachians continue in Scotland
In today’s blog post, we continue our story of the development of the theory of continental drift – an idea which just celebrated its 100th birthday. Before Alfred Wegener’s 1915 book on contintents in motion, a few others had the idea, yet no one had developed it as thoroughly. In Part 1 of this series, we covered a bit of Alfred Wegener’s early life and some of his initial work. Yesterday, we showed how fossils and palaeoclimate figured into his continental drift theory. Today, we continue with Wegener by looking at his idea in a little detail.
On Saturday, January 6, 1912, Wegener presented a lecture that unveiled his hypothesis of a supercontinent and the idea that it fractured into our modern continents. He gave his talk to the German Geological Society at the Senckenberg Museum in Frankfurt. Probably no one in attendance believed his notion – they…
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The evidence mounts: glacial striations, coal in Antarctica, and the distribution of dinosaurs (and others)
It’s been 100 years since Alfred Wegener proposed his idea of continental drift. Today’s blog continues the story we began yesterday – the tale of Wegener’s life and the development of his grand idea of mobile continents. This time, we’ll look at the significance of fossils and climate and how these contributed to the drift theory.
By 1900, most geologists and biologists accepted Darwin’s description of species evolution. Darwin noted that the offspring of various creatures, isolated from each other and exposed to different environments, evolve into quite different beings with the passage of time. For example, bison arose on the American plains while the wildebeest fills a similar ecological niche in Africa. Both form huge herds, mostly survive by grazing (eating grass and seeds), but also by a little browsing (munching on the odd shrub). Both animals have manes, wild beards, and both look like trouble.
But you would…
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Wegener is not the only scientist for whom meteorology has been the starting point on the path to other major discoveries. It influenced Dalton’s thinking in the development of atomic theory, while writing computer programs for meteorology was Paul Crutzen’s first step towards discovering how CFCs were destroying the ozone layer.
Wegener himself gets a supporting role in the admirable Horrible Science book (reviewed here), Evolve or Die.
Alfred Wegener, in Greenland, 1930 (photo by Fritz Loewe)
Fifty years ago, we finally figured out why the Earth has mountains. But one hundred years ago, Alfred Wegener had already offered an explanation – it took those extra 50 years for his grand idea to catch on. The continents, Wegener said, wander about. They bump into each other. Accidents cause mountains.
Yea, it’s been a hundred years since Wegener first wrote about continental displacement. A few other people had similar notions earlier. In the 1600s, Francis Bacon speculated that the southern hemisphere’s continents were arranged “like an opening blossom.” Some say Bacon was wondering if they had drifted from an original supercontinent, though Bacon never really said that.
In the 1800s, a few notable geologists (particularly Antonio Snider-Pelligrini, in France, and Richard Owen, in the USA) claimed that the continents were mobile. But their cases weren’t as compelling…
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Re-blogged from Michael Roberts’s How fiendish is Friends of the Earth?
Fracking fluids contain sand. Sand contains silica. Silica can cause silicosis and even cancer. Therefore fracking is bad. Send us money.
But it’s notFriends of the Earth, who are saying this, because Friends of the Earth is answerable to the Charities Commission. It’s Friends of the Earth Limited, a profit-making subsidiary outside the Commission’s terms of reference. Much as the Global Warming Policy Foundation, whose purpose is to deny global warming, issues its materials through a separate legal entity, the Global Warming Policy Forum.
We need rational discussion aboutfracking and its place in overall energy policy. And what are Friends of the Earth contributing towards this discussion? Crusading zeal in place of rational reflection, demonisation where we most need discourse.
For a time I was an active member of Friends of the Earth and supported all they did. I then moved house and job and my membership lapsed. That is something I regretted as I felt I should be do more for the environment and that Friends of the Earth was one of the best organisations doing that.
That remained the case until March 2014 when I went to a meeting organised by RAFF (Residents against Fracking; Fylde) at Inskip (10 miles from Preston). I was unimpressed with the low level of accuracy in the presentation. i challenged some of this and to my surprise the local FoE activist supported the speaker in the inaccuracies. In two minutes my respect for FoE evaporated. RAFF also handed out a leaflet Shale Gas; the Facts which they withdrew after a complaint to the Advertising Standards Authority.
Over the next 15 months…
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Respectfully reblogged from Pigliucci’s Plato’s Footnote. Historically, an accommodationist was a believer who, like William Buckland (Dean of Westminster), or the Free Church of Scotland theologian Henry Drummond, sought to accommodate their interpretation of their faith to scientific discoveries. More recently, the term has been used to refer to those who neglect to sufficiently disparage religion while expounding science, a neglect that some consider sinful.
A recent essay I wrote for The Philosophers’ Magazine online has, predictably perhaps, generated a minor storm (well, more likely a tempest in a teacup, but still). The piece is what I thought amounted to a mild, substantive criticism of a well reasoned piece by independent philosopher Russell Blackford, entitled Against accommodationism: How science undermines religion. Russell, in turn, was reviewing (very, very positively) the latest book by biologist and New Atheist Jerry Coyne, Faith Versus Fact: Why Science and Religion Are Incompatible. I am a known critic of New Atheism (though myself an atheist) so I figured I’d add my two cents once again.
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You may remember my daughter-in-law, Nikki, who died last year as the result of an extremely virulent form of leukaemia. One contributing factor may have been (we cannot possibly tell) the unusual difficulty in getting a good bone marrow donor match, since Nikki was of mixed European-Asian parentage, and a good match depends on characteristics inherited from each parent.
Geoffrey, Nikki’s widower, is drawing attention to another such case:
Any healthy person under 55 (details vary from country to country) should consider registering as a a bone marrow donor. More available donors will mean better matches in all categories, but there is a particular need for non-European donors, and especially donors of mixed ancestry. You can register with one of these organisations:
§ UK, aged 16-30: The Anthony Nolan Trust
§ UK, aged 18-49: The British Bone Marrow Registry
§ UK, aged 18-55: Delete Blood Cancer
§ Australia (there’s a large Anglo-Burmese community in Perth): Australian Bone Marrow Donor Registry
§ US: Be the Match
§ Canada: One Match
§ Worldwide: Bone Marrow Donors World Wide
Or just google “Bone marrow donation [name of country]”
Registering is easy. Donation, should you be called on, a minor inconvenience for you, and a matter of life and death for some total stranger, whose name you will never know.
Please pass this on
Have you heard the one about the live snail with a carbon-14 age of 3000 years? Or the lava erupted in 1800 in Hawaii with a potassium-argon age in the millions? It’s all true, true I tell you. But does this signify a major problem with radiometric dating?
I don’t know who first dug up these examples, but they were popularised by the creationist comic-book writer Jack Chick, in a publication called “Big Daddy”. The first page, available here if you’re lucky (the links to Chick Publications only seem to work at random), shows a well-primed creationist student arguing with a singularly ill-informed biology professor. The professor has been leading such a sheltered life that he’s never met these creationist arguments before. And he doesn’t understand anything about evolution or dating of rocks or embryology or indeed anything else. Surprise! the student wins! A skilled cartoonist, Jack Chick manages to squeeze the largest number of fallacies into the smallest number of words. There is a crib sheet at the end of this post, listing all the fallacies I spotted myself; I just reached double figures but there may be more.
Of course, it doesn’t help that the Professor doesn’t know anything about whale ancestors:
Or that the student is allowed to make the most absurd statements unchallenged, on the basis of a video by Kent Hovind:
But there’s more! At the end of page 1, which is also the end of your free sample I’m afraid, the student converts the Professor by pointing out that no one has ever actually seen gluons:
But fear not; an answer is at hand, in the very next frame:
So Jesus must be the force that holds the atomic nucleus together. Convinced by this reasoning, the Professor accepts Jesus, announces that as a result he can no longer teach evolution, and is sacked.
Jack Chick, by the way, has just published another comic book at the age of 92. In it, a bright young man from a good Christian (i.e. creationist) home is seduced by Satan into believing in evolution, and when we last see him is heading straight for damnation. In the words of one of Satan’s many horned helpers, “Joe trusted evolution, not God, and became a jobless party animal.” And a criminal and a drug addict, and covered himself with tattoos, and died and went to hell. Tragic, and so easily avoidable.
I never managed to get to Page 13 of Big Daddy, which is what we really need; link (if it works for you) here. It didn’t work for me, but you’ll find a description of the contents by someone called Honus at talkorigins, and I’ve seen some of the relevant cartoons reproduced elsewhere. So you can either take Honus’s and my word for it, or go online to Chick Publications and buy 25 copies (minimum purchase) of the tract, which I am not about to do.
The really remarkable thing about the tract is that it actually gives the primary literature references to the results that is discussing. And the briefest perusal of this primary literature will show why the papers that Chick refers to, far from undermining radiometric dating, actually reinforce it.
That snail was not 3000 years old, but that really was its apparent radiocarbon age, because it was exchanging calcium carbonate in its shell with mineral calcium carbonate. And that makes all the difference, so you need to take such features of the environment into account.
Many readers will be familiar with the principle of carbon-14 dating. Carbon-14 decays with a half-life of 5730 years. Nonetheless, the fraction of carbon-14 in the atmosphere stays roughly constant (or did before we started adding to it by nuclear weapons testing, and diluting it with carbon dioxide from fossil fuels). That is because the upper atmosphere is bombarded with cosmic rays, which cause nuclear reactions that convert nitrogen-14 (stable) to carbon-14. Mixing distributes this radiocarbon through the atmosphere, where it is taken up by plants and, in due course, animals. As long as you are alive, you are part of the circulating pool of carbon, but as soon as you die, the carbon-14 in your body starts decaying. Of course, cosmic ray intensity is not really constant over a long period, but we can calibrate carbon-14 dates by comparison with carbon in tree rings (dendrochronology). The tree ring correction is small for most purposes, but matters for things like precise dating of Egyptian dynasties.
The point, of course, is that the carbon in the lettuce being fed to the snails is part of the general pool, but the carbon in calcium carbonate minerals is radiochemically dead, having been out of circulation for a long time. What the paper really showed was that the snail exchanges carbonate in its shell with carbonate from dissolved minerals, giving a spurious depletion of radiocarbon in the snail. You will find the story in Science, 1963, p. 637 (paywall, sorry, but summary here).
What about these rocks in Hawaii? Here again the paper is behind a pay wall, but if you follow this link it will take you to the title and abstract, which is all you need. In fact, the title alone is all you need: “Radiogenic helium and argon in ultramafic inclusions from Hawaii”. Inclusions. And in case that’s not clear enough, the abstract tells you that the work is all about the dating of xenoliths. Xeno- foreign, as in xenophobia; lith rock, as in monolith. Look at the paper in more detail, if you can get access to it, and you will find that the excess argon is only found in bubbles of fluid within the rock, that bits of rock that aren’t bubbly don’t show any, and that there is circumstantial evidence that the argon comes from deep within the Earth’s mantle, not radioactive decay in the lava itself.
Anomalies happen all the time in geology. They are, in the original sense of the expression, exceptions that prove the rule; if there were no rule, we would not consider them exceptional. Uranium-lead and potassium-argon dates of rocks usually agree, but not if the rock has been so strongly heated that argon gas can escape. Whole rock dates can be misleading, as in the example of the Hawaiian volcano, if the rock has been contaminated from some source, in this case fluid from the mantle. So far from undermining the method, these anomalies add further information about the sample. In much the same way, radiocarbon dates will be anomalous if some of the carbon comes from inorganic sources, as in the case discussed above, and the anomaly might even be used to tell us something about the specimen’s history and diet.
Now here’s the bit that I really don’t understand. What is going on in Jack Chick’s mind, when he gives us this stuff? I assume that he is an honest person of goodwill, who is doing his best. He really believes that because I and most readers here accept the fact of evolution, we are going to be punished in hell for ever. Being a kindly man, he really doesn’t want that to happen, so he is doing his very best to convince us of the error of our ways.
So why does he do it by pointing us towards papers that say the very opposite of what he says they say? I can only speculate that this is the result of what psychologists call confirmation bias, which leads to interpreting new information, however perversely, in a way that supports what you already think. And when we come to creationism, the motivation for bias is extreme. Remember that we are talking about people who really believe (a) that if you don’t accept salvation through Jesus you are going to go to hell, and (b) that the doctrine of salvation through Jesus only makes sense if the biblical Fall is a historical fact. The papers I’ve mentioned above show that under certain rather special circumstances, radiometric dating will give you the wrong answer unless you take those circumstances into account. Young Earth creationists, knowing that their entire worldview depends on refuting radiometric dating, pounce on these examples as evidence that the method is unreliable. Which of course it is, if you don’t do it right. So what?
All of which gives me uncomfortable pause for two reasons. If creationists are so blinded by confirmation bias, what hope is there of reasoning with them? And if I see my intellectual opponents displaying confirmation bias, completely oblivious to what they are doing, what makes me think that I am any different?
h/t Sensuous Curmudgeon for tip-off about Jack Chick’s latest. Whale ancestors illustrated (Ambulocetus and Pakicetus) copyright JGM Thewissen; may be reproduced for non-commercial educational purposes.
Crib sheet: Definition as obfuscation. Misdefinition of science to exclude all indirect inference (although even Young Earth creationists accept the fact of an Ice Age on geological evidence). Macroevolution, if the word means anything, means major change, and this takes more time than we have been watching. So of course we’ve never seen it. Similar fossils do indeed imply similar ages, but the order of these ages has been known for nearly 200 years on the basis of stratigraphy, and absolute ages established for over 100 years now by radiometric dating. Polystrate fossils were explained in 1868; the explanation is much the same today. New Scientist really did point out in 1997 that it is silly to carry on using Haeckel’s highly questionable drawings, as some still do, when we now have a much more detailed information. But, as explained in Alice Roberts’s Incredible Unlikeliness of Being and many other places, the gill folds on the human embryo really are homologous to the folds on that of a fish. They just develop rather differently, explaining such oddities as the tortuous path of our vagus nerves. As for the whale’s pelvis having “nothing to do with walking on land”, by 1999 we already had extensive series of fossils linking whales to their terrestrial ancestors; there is an excellent review here by one of the scientists involved in Evolution Education and Outreach (free download), and whales evolution also features in an excellent video here . The development of secondary functions (exaptation) is commonplace. Thus mammals’ ear bones are vestigial relics of reptiles’ rear jawbones. Creationists often argue, as here, that natural selection can only remove, and not add. This riddle was solved 120 years ago, with the discovery of mutation. Mutations supply novelty; selection winnows it. Creationists agree in explaining away pre-modern human fossils, such as Lucy and numerous others already known by 1999, as being either apes, or humans. Unfortunately, they can never agree on which is which. And, something that I think believers in particular should find offensive, the theological absurdities of the final frame.
Casey Luskin has just announced his departure from the Discovery Institute, in order to further his studies. We will miss the enlightenment that he brings. For example, in his farewell piece, he tells us that
Evolutionary biologists are now admitting we need “post-Darwinian” models to explain the Cambrian explosion.
Casey is right; we really do need “post-Darwinian” models to explain the Cambrian explosion. Things like Mendelian inheritance, mutation, population genetics, and, in this context, palaeogeochemistry, which is why evolutionary biologists have been decidedly post-Darwinian since around 1905.
Casey does not tell us what he is going to study, but I rather hope that it will be chemistry. Then, in due course, he will be fully equipped to explain to us that Dalton couldn’t even get the structure of water right, that Faraday’s electrical theory of bonding needs to be revised in the light of quantum mechanics, that many of the postulated intermediates in chemical reactions have never even been observed, that (as predicted by Intelligent Alchemy) many of Lavoisier’s elements turn out not to be elements at all, and that our schools should allow students to evaluate for themselves the unwarranted metaphysical assumptions of chemical materialism, and the merits of the phlogiston theory.
Disclosure: unlike many far better people, I have been insulted by Casey only once, when he accused me and the British Centre for Science Education of concealing our atheism for tactical reasons. Guilty as charged; we conceal it so well that one of BCSE’s most prominent members at the time, now its official spokesman, is an Anglican priest. Devious, these evolutionists. You need to watch them.
Casey, you will be sadly missed.
Update; more here: http://pandasthumb.org/archives/2016/01/luskin-i-am-lea.html The word is that he will be replaced by Ann Gauger, who knows more biochemistry and therefore has, and uses, a much greater capacity for misunderstanding.
(By a curious chance, I came across this post by Massimo Pigliucci less than three hours after posting the most politically partisan of all my own posts to date.)
The dispassionate scientist is a myth (or perhaps a Stoic’s ideal). We all show personal involvement in our theories and research programmes, and confirmation bias when evaluating them. But if we stay out of political activism, that will deprive the public of the best informed opinion.
And when we indulge in activism, then of course we should aim to do so competently. I consider public understanding of major issues to be a precondition for sane policy-making, and for this reason I regard my own efforts at public education as a form of activism.
That’s the question I tackled in a recent essay at The Philosophers’ Magazine online, prompted by a conversation over coffee with Jonathan Haidt, a social psychologist at NYU with whom I’ve had a number of disagreements about the intersection of social science, politics, and philosophy.
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Floods are inevitable. But the degree of damage that we are seeing today is the result of reckless cuts, perverse subsidies, and mindless deregulation.
First, a review of “savings” (that’s NewSpeak for “cuts”) on flood defences:Well, Labour would say that, wouldn’t they? But @LabourEoin gives fuller links; for instance, the last set of numbers comes from House of Commons Library Note “Flood spending in England”, SN/SC/5755, 19 November 2014.
Well, maybe the Government have learned better? Then why are they cutting 6700 firefighters, who are among first responders and prevention workers in floods?
Well, maybe it is necessary to save money? It would be difficult to think of a more expensive way of saving, where every £ saved costs somewhere between £6 and £24, depending on which estimate you accept. Even if you accept government forecasts of future flood damage as accurate estimates, it makes no sense that
Under the new rules brought in three years ago, the Department for Environment Food And Rural Affairs (Defra) wanted to see an average of £8 of damage avoided for every £1 they would spend on schemes.
Previously, projects were simply expected to deliver more than £1 of damage avoided for every £1 spent, with an average across all schemes of £5 of damage avoided for every £1 spent.
(Source: Rowena Mason in Guardian, commenting on the Somerset Levels floods, in 2014; h/t Jonathan Minton)
But aren’t things like this terribly rare? In that case, why do they happen so often? As Nassim Nichoas Taleb has pointed out (and become extremely rich by acting on his own insight) extremely rare events are more common than you think. That’s because we form our expectations from the commonplace, constructing something like a bell curve of expectations based on the fluctuations that happen all the time, but rare events can also arise from rare combinations of circumstances. Five year floods can be expected to happen every five years or so, butwe have little experience of the statistics of hundred year floods, and they may well happen much more often than once every hundred years.
[Update: for more on the frequency of “100 year floods”, and of ministerial obliviousness to explicit warnings, see here]
But can the Government be blamed for natural disaster? Yes, when its policies have directly and foreseeably contributed to it. See this from George Monbiot, in January 2014:
“Drowning in money: the untold story of the crazy public spending that makes flooding inevitable”
And this in February 2014:
“How we ended up paying farmers to flood our homes”
Or very recently (29 December 2015) this:
“This flood was not only foretold – it was publicly subsidised” (which – Scottish friends note – mentions grouse moors)
(And more in the same vein; Google Monbiot Flooding Guardian and you will see the case argued, consistently and coherently, again and again.)
Not only is this Government cutting back disastrously on flood protection at the very time when climate change is increasing risk; it is spending lavishly on policies that help make sure that those floods will be as damaging as possible. The challenge of flooding is unavoidable, but the degree of disaster is man-made.