Friday, May 30, 2008

Ben Stein gets an F.

It is a behavior we see rather often, usually in the context of the faux "debate" over anthropogenic global warming, and we ought start condemning it loudly until it is universally considered shameful: people who refuse to learn even the basics of a scientific theory not only feel entitled to have an opinion on it (as if that isn't bad enough!) but also to express that opinion publicly as though it is of equal merit, and to slander, implicitly or explicitly, the experts.

Ben Stein and his writing and production team didn't bother to learn what every high-school graduate should know about the modern theory of evolution, rendering an already poorly-produced film not only wrong, but bad. My review of their film Expelled is now (belatedly) posted on

Thursday, May 29, 2008

More insight on the Mentos eruption

The June issue of the American Journal of Physics (the AAPT's flagship publication) contains a report by Tonya Shea Coffey of Appalachian State University on an undergraduate class project concerning one of the Youtube-era Internet's favorite kids' pranks: the Mentos eruption.

Fruit Mentos and Mint Mentos were found to cause nearly equal emptyings of Coke bottles. Playground sand, among other things, was an adequate substitute. Diet Coke and Coca-Cola were nearly equally emptied by the Mint Mentos. Differences between Diet Coke and Caffeine Free Diet Coke were not clearly statistically significant.

The Diet Coke-Fruit Mentos combination, however, produced the longest jet, followed by the classic Caffeine Free Diet Coke-Mint Mentos pairing. Further investigation by Coffey and her students showed from photographic evidence that aspartame reduces the work needed to form a critical bubble compared to plain seltzer water and that less work is needed to form a bubble in Diet Coke than in plain Coca-Cola. SEM study found that Fruit Mentos and Mint Mentos are nearly equally rough. Moreover, unlike a wax coating previously applied by the "Mythbusters", Fruit Mentos' coating dissolves rapidly in soda water. The researchers speculate about Mentos having a surfactant component but take no measurements.

Fairly useless research, yes, but it gets students thinking about questions more subtle than those found in introductory textbooks, provides a means of introduction to surface science intersting to the common eighteen-year-old, and it's more practical than quite a bit of what ends up getting funded by DARPA.

HT: Chronicle of Higher Education

Wednesday, May 21, 2008

Porter Hypothesis now on sound footing, but does it apply to our world?

As a physical scientist, I take a very negative view of the "talk arguments" still common in economics. Qualitative explanation is nice, but one cannot prove or argue anything with mere qualitative work. There is no qualitative scientific methodology.

Michael Porter put forth a few years ago an idea with great appeal: under some circumstances, strict environmental regulations can be a win-win situation, both reining in the negative externality and inducing firms to eliminate waste and innovate, simultaneously increasing profits and R&D spending.

More recent work by Stefan Ambec and Philippe Barla puts this onto more solid footing. Note that the result is parameter-dependent. One would have to be a slob to say that the Porter Hypothesis (which really should now be called the Ambec-Barla Theorem) implies that there is no such thing as a bad environmental regulation.

In a recent review, Ambec and Barla appraise the empirical evidence, and find that, while case studies can be found on either side, most of the time there are no Porter effects. Whether this is an artifact of the existence of pollution havens is one of many open questions.

Win-win environmental regulations remain a tantalizing possibility but not an everyday reality. Perhaps we'll never be able to "have our cake and eat it too". Science, including economics, should inform our policy decisions to the greatest reasonable extent, but problems such as this make it clear that we'll always be caught with value judgements and shades of grey.

Tuesday, May 20, 2008

Why would-be climate skeptics are treated poorly by scientists.

Consider the following: You or your colleagues put more time and effort than nonscientists can usually understand into bettering our understanding of nature, present your work at conferences before the world's most genuinely skeptical audiences, write it into papers, revise papers to satisfy editors, and begin the cycle anew.

A journalist, an ideologue, or an "eminent historian" comes along, decides he'd rather your result be false, and writes, to the general public, without filtering his thoughts through the baloney check called "peer review", that you don't know what you're talking about. His justification: two minutes' work finding a question he can't answer for himself due to his own ignorance. A variation on the classic "argument from incredulity": I don't know, therefore the experts don't know, either.

What, specifically, am I talking about? Take for instance "respected", "eminent", etc. historian Don Aitken , being interviewed in The Australian:

He says an increase in atmospheric levels of carbon dioxide over the past century is agreed, some of it due to fossil fuels, cement-making and agriculture. However, normal production of CO2 is not known, and it makes up only a tiny part of the atmosphere. "How does a small increase in a very small component have such a large apparent effect? The truth is that no one has yet shown that itdoes."

The truth is that the Greenhouse Effect has been understood for decades, and is noncontroversial.

Forget being polite and gentle with the lay public. I'm going to stick my head out the window and yell like Howard Beale the anchorman in Network advised. I'm mad as hell. If you are too lazy to learn the basics, you have no business having an opinion on a scientific matter, let alone expressing it publicly.

Friday, May 16, 2008

Willis Lamb, RIP

Willis Lamb, a major contributor to atomic physics and laser theory and recipient, (split with Polykarp Kusch), of the 1955 Nobel Prize in Physics for measurements of hydrogen fine structure (including his eponymous shift) died today from complications of a gallbladder disorder. He was ninety-four years old.

Lamb's career arc is quite interesting. He performed his PhD work under the direction of Robert Oppenheimer performing neutron scattering experiments to probe the electrical properties of the atomic nucleus. He went on to become a pioneer of microwave spectroscopy; his measurements (largely in collaboration with Robert Retherford) of the electronic fine structure of hydrogen provided an early test for quantum electrodynamics.

Note the short length, relaxed language, and fast turnaround at Physical Review sixty years ago. Some things have not changed for the better!

Later in his career he shifted somewhat to being a theorist, becoming a major contributor to the theory of lasers, including the now ubiquitous ring laser gyroscope. In his many later years he also became in many ways the official curmudgeon of quantum optics and the University of Arizona's Optical Sciences Center, infamously offering "licenses" for use of the term "photon". Most of his theoretical work was done in a semiclassical formalism; some of it would almost seem to imply that he was never quite comfortable with quantization of the light field and sought to avoid it if possible, but his 1994 essay in Applied Physics B, "Anti-Photon", is right on the money and worthwhile reading for anyone interested in fundamental physics. "Photon" is not a synonym for "light" or "radiation", the electromagnetic field cannot be considered to be like bowling balls or an atom beam, and one certainly should not be able to claim with a straight face, especially after even a few hours studying quantum optics, that lasers "produce vast numbers of particles of exactly the same energy and wavelength."

Lamb is survived by his wife Elsie, his brother Perry, and many former students and collaborators. An official obituary can be found on the University of Arizona website.

Thursday, May 15, 2008

Connections in physics, 21st-century style

Spectators of science often miss what working scientists consider "cool", instead being dazzled by counterintuitive results and "gee, they can really do that?"

To physicists, finding relations between quantities previously seen as independent--the canonical example being the relationship between coupling constants and particle masses--being thus able to indirectly measure things of interest, is one of the joys of the field. "Connections in physics"--finding that different phenomena are governed by similar laws--is yet another.

In March's Physical Review E, Northwestern University biophysical theorists Houyin Zhang and John Marko derive analogues of the Maxwell relations familiar to science undergraduates, allowing experimenters to (among other things) find the number of proteins bound to a nucleic acid molecule from force-extension measurements, without a microphysical model for the mechanism of binding.

From the point of view of someone who works daily with optical tweezers: very cool.