A great movie cliche debunked. According to scientist Daniel Bonn in Nature, quicksand cannot suck you under. You will not sink out of sight. However, because the basement of quicksand is clay, you cannot simply be pulled out, either.
Note – the list in the first link is text, but given that quicksand scenes are frequently played for titillation, there is an 18+ warning on the visuals on the site.
From Science, May 27, 2005, an intriguing article on “Physical Limits and Design Principles for Plant and Fungal Movements” (Jan M. Skotheim, L. Mahadevan). Most plants move slowly; some move swiftly – Hura crepitans shoots out seeds at up to 70 m/s, Venus flytrap catches insects in ca 0.2 s, and the fungus Dactylara brochopaga swells to trap nematodes in 0.1 s. Other examples of quick-moving plants: the fungus Philobulus, Catasetum orchids and Stylidium triggerplants, Mimosa. The plants exploit the large internal pressure (turgor) that having a cell wall allows them to have, and motion is determined by the rate of fluid transport. The authors publish a colorful plot of time scale versus the smallest macroscopic dimension of the moving part, and group the types of movements into swelling/shrinking (durtion limited by fluid transport), snap-buckling, and explosive fracture, the latter two being a result of elastic instabilities. The biggest, fastest movements are made by Hura crepitans, and Eclallium elaterium – if I’m reading the colours on the chart right, and they’re less than 10 mm in 0.001 – 0.0001 s, which alas means all our favourite big nasty plants fall in the section of the plot marked “Physically impossible movements”, at least if they’re restricted to using water pressure. The authors contrast the Venus flytrap (0.2 s) and Aldrovanda (0.02 s): an Aldrovanda leaf is about 1/10th the size of a Venus flytrap leaf, which should translate to about 100 times the speed, but the design of the Venus flytrap leaf includes a reversal of curvature and a snap. If you want to see pictures, then the (unrelated) site Plants in Motion has Quick Time movies of a Venus flytrap closing, and a Mimosa leaf curling up like a blind when the tip is warmed.
Here is something I really appreciate, because it was something I set out to do in my earlier days – crystallize an ion channel. Went about it all the wrong way, so never got as far as I might, but somebody did, and now Roderick McKinnon has received the 2003 Nobel prize for Chemistry for a series of gorgeous, elegant experiments that led to a series of revelatory structures of ion channels, including a blow-the-paradigm visualization of the switch that senses changing voltage in voltage-dependent channels. His work is described in a long interview done at the time (1999) he won the Lasker, and also in a series of detailed press-releases put out by the Howard Hughes Medical Institute, where he works (see the links in the HHMI announcement of his Nobel). For the papers themselves, if you have access to Nature, they have a focus page on Ion Channels: Structure and Function. To someone who has tried expression and crystallization, the sheer physical labor, endless repetitions, and inevitable frustration that can be read between those lines are awe-inspiring. As a historical note, in 1988 Hartmut Michel, Johan Deisenhofer and Robert Huber won the Nobel prize for solving the three dimensional structure of a photosynthetic reaction center; it was the first membrane protein crystallized.
“For a generation now, the academic left has been engaged in a war against science as we know it: propagating the notion that science is an inherently Western concept, that it is culturally perspectival, but most of all, after Werner Heisenberg, that it is an imperfect and thoroughly flawed ‘discourse’.” … Patrick West’s argument is that the postmodernist insistance that “there is no such thing as truth; there is only interpretation”, and their readiness to interpret the (sexy) metaphors of uncertainty, chaos and relativity as the reality, while disregarding the mathematical and theoretical underpinnings of all of those, have led to an erosion of understanding of the absolutes of science. Add to that the various political movements – of varying degrees of self-servingness and idealism – trying to qualify or undermine the actual or perceived supremacy of science in our culture, and there are a number of converging philosophies and fields of thought arguing that science is just another belief-system. Add to that the fact that, although technology may be privileged, science actually isn’t – or there would not be such wisespread innumeracy and scientific illiteracy as there is – and, to paraphrase the very famous line, we’ve got a problem.
Last months’ Scientific American had an article on the teaching of evolution in US schools. Highly variable, and in places – actually, in some unlikely places – appalling. I have no idea what Canada is like. I suspect, unhappily, that it may be akin to the liberal states, prepared to sacrifice science to social and cultural inclusiveness. (You can tell I’m in the 37% who are of the opinion that creationism does not deserve any mention in a science class, can’t you … which by the way may be a minority but is not a small number.)
Last line: “Many who are indifferent to conservative theology give creationism some support, perhaps because, as mathematician Norman Levitt of Rutgers University suggests, the subject of evolution provokes anxiety about the nature of human existence, an anxiety that antievolutionists use to promote creationist ideas.” Note that whose anxiety is never said. Evolution is quite clear about the nature of human existance. People just don’t care for its interpretation. It doesn’t just knock God off his plinth, it knocks man off his pedestal. It raises questions. People who wish to control – others beliefs or freedoms, or the natural world – are threatened by questions.