Tuesday, April 23, 2013

Alternative History

I recently read A Palette of Particles, another fine book by the writer and physicist Jeremy Bernstein about the history of particle physics up to the Higgs boson. Bernstein mentions one chilling near miss in physics. In Rome in 1934 an Italian team led by Enrico Fermi actually observed nuclear fission. But they misinterpreted what they saw. Bernstein asks us to imagine how world history might have been different if fission was discovered in Fascist Italy in 1934 instead of four years later in Berlin 1938. Even though fission was discovered in Germany, by that time, the fascist powers were rapidly becoming very isolated from the rest of the scientific community. Lack of scientific knowledge might have been only part of the reason the Nazis weren't able to build a bomb, but it was probably a factor. After WWII several distinguished German scientists were held together by the Allies in England (Operation Epsilon) and their conversations were secretly recorded. Several of them, including Heisenberg, seemed surprised when they learned of the atomic bomb and may have mistakenly believed that an explosion would require tons of uranium, not kilograms.

Saturday, April 06, 2013

The Variational Principles of Mechanics

I'm currently reading The Variational Principles of Mechanics by Cornelius Lanczos, the fourth edition published in 1970. From the preface to the first edition (1949):
The variational principles of mechanics are firmly rooted in the soil of that great century of Liberalism which starts with Descartes and ends with the French Revolution and which has witnessed the lives of Leibniz, Spinoza, Goethe, and Johann Sebastian Bach. It is the only period of cosmic thinking in the entire history of Europe since the time of the Greeks
The Action Principle may be the most profound principle in all of nature. The 18th century origins of the principle were colorful and controversial. Characters who were deeply involved included Émilie du Châtelet, an aristocratic lady; her lover, the writer Voltaire; and Fredrick the Great, King of Prussia! See The Berlin Academy and forgery.
Du Châtelet was a remarkable woman, her French translation of Isaac Newton's great work Principia Mathematica is still considered definitive. Café Gradot was the meeting place for intellectuals in Paris at the time, many of them her friends. When she tried to join her friends at their table, the management threw her out - women were not allowed in the cafés at the time. Undeterred, on later occasions she arrived attired as a man, and was able to participate in the discussions at the cafe without further incident.