Hal Lewis quits APS

10/10/2010

Climate Change – News & Comments

Prof. Hal Lewis resigns from the American Physical Society

Going along with Anthony Watts’ suggestion that this should be posted on every science blog, I have merely added a photo,  some emphasis, and some bulleting.

From: Hal Lewis, University of California, Santa Barbara

To: Curtis G. Callan, Jr., Princeton University, President of the American Physical Society

6 October 2010

Dear Curt:

When I first joined the American Physical Society sixty-seven years ago it was much smaller, much gentler, and as yet uncorrupted by the money flood (a threat against which Dwight Eisenhower warned a half-century ago).

Indeed, the choice of physics as a profession was then a guarantor of a life of poverty and abstinence—it was World War II that changed all that. The prospect of worldly gain drove few physicists. As recently as thirty-five years ago, when I chaired the first APS study of a contentious social/scientific issue, The Reactor Safety Study, though there were zealots aplenty on the outside there was no hint of inordinate pressure on us as physicists. We were therefore able to produce what I believe was and is an honest appraisal of the situation at that time. We were further enabled by the presence of an oversight committee consisting of Pief Panofsky, Vicki Weisskopf, and Hans Bethe, all towering physicists beyond reproach. I was proud of what we did in a charged atmosphere. In the end the oversight committee, in its report to the APS President, noted the complete independence in which we did the job, and predicted that the report would be attacked from both sides. What greater tribute could there be?

How different it is now. The giants no longer walk the earth, and the money flood has become the raison d’être of much physics research, the vital sustenance of much more, and it provides the support for untold numbers of professional jobs. For reasons that will soon become clear my former pride at being an APS Fellow all these years has been turned into shame, and I am forced, with no pleasure at all, to offer you my resignation from the Society.

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Self-organizing colours of butterflies

17/06/2010

Updating Magic Universe

Self-organizing colours of butterflies

The papilionid Emerald-patched Cattleheart, Parides sesostris. Source: Richard Prum

A multi-disciplinary study at Yale, by evolutionary biologists, physicists and various kinds of engineers, aided by X-ray scattering specialists at the Argonne National Laboratory, has clarified the way in which butterfly wings generate shimmering colours. The wings employ a physical trick of the light that’s more influential than any chemical pigments. The team, led by biologist Richard Prum, has published the findings in this week’s on-line issue of the Proceedings of the National Academy of Sciences.

A gyroid, as visualized by Alan Schoen. Image from NASA

Complex curved assemblies of molecules called gyroids do the trick, by scattering light in distinctive ways that depend on the dimensions of the gyroids, the slant of incoming light, and the angle of view. Digging a little, I find that a mathematician, Alan Schoen, discovered gyroids as possible shapes, long before their biological role was known. In 1970, while at the Electronics Research Center in Cambridge, Massachusetts, Schoen wrote a paper for NASA that began: “A preliminary account of a study of the partitioning of three-dimensional Euclidean space into two interpenetrating labyrinths by intersection-free infinite periodic minimal surfaces …” Key words there are “labyrinths” and “periodic”.

But how does a butterfly, however mathematically astute, set about building its gyroids?  According to Prum and his chums, the outer membrane of a cell in the butterfly’s wing folds into the cell’s interior from above and below to make a double gyroid. Then starchy chitin forms on the outer gyroid to solidify it before the cell dies – leaving the colour-generating crystal form on the surface of the wing.

Here’s the most relevant story in Magic Universe. It’s called “Molecular partners: letting natural processes do the chemist’s work”.

Strasbourg or Strassburg lies in the rift valley between the Vosges and the Schwarzwald, down which the Rhin or Rhein pours. The city is closer to Munich than to Paris, and repeated exchanges of territory between the French and the Germans aggravated an identity problem of the people of Alsace. It was not resolved until, after restoration to France in 1945, Strasbourg became a favoured locale for Europe-wide institutions. But history left the Alsatians better able than most to resist the brain drain to Paris, and to pursue their own ideas, whether with dogs, pottery or science.

As a 28-year-old postdoc in Strasbourg, Jean-Marie Lehn embarked in 1967 on a new kind of chemistry that was destined to become a core theme of 21st-Century research worldwide. It would straddle biology, physics and engineering. As it concerned not individual molecules, made by bonding atoms together, but the looser associations and interactions between two or more molecules, he called the innovation supramolecular chemistry.

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