Friday, July 8, 2011

Unmoved by considerations of beauty

Arthur I. Miller reviews Quantum Man: Richard Feynman's Life in Science, by Lawrence Krauss:
Krauss argues persuasively for the importance Feynman placed on experimental data at every stage in his theoretical work. However, I must disagree with his claim that Feynman was unmoved by considerations of beauty, or that data were all that mattered. In 1957 Feynman and Gell-Mann worked out a theory of the weak interaction that conflicted with key experimental data. Feynman insisted, along with Gell-Mann, that the data were wrong: "There was a moment when I knew how nature worked. [Our theory] had elegance and beauty." The experiment was redone and the data indeed turned out to have been wrong. This was a bold move with few precedents, although Einstein, with a similar aesthetic bent, had asserted in 1907 that data conflicting with the special theory of theory of relativity were incorrect. He was right too.
Miller thinks that there is some sort of virtue in a scientist ignoring the data.

Lorentz and Poincare explained why their relativity theory was better than the competing theories, but had to admit that it could be proved wrong by experimental data. Einstein did not even pay much attention to experiments, according to historians like Miller.

Einstein's 1907 comment was:
It will be possible to decide whether the foundations of the relativity theory correspond with the facts only if a great variety of observations is at hand... In my opinion, both [the alternative theories of Abraham and Bucherer] have rather slight probability, ...
Here, Einstein is defending Lorentz's theory. Lorentz got the 1902 Nobel Prize, and had the more established and accepted theory at the time.

In 1907, the aesthetically preferred version of relativity was the spacetime geometry theory of Poincare and Minkowski. However, Einstein did not even understand it, and did not mention it in his relativity review paper.

At that time, Einstein's relativity was nothing more than an exposition of Lorentz's theory, along with Poincare's clock synchronization. That is how everyone understood it at the time. Not even Einstein claimed that it was anything more. Einstein did not need to consider the experimental data, because he trusted Lorentz's analysis of the experiments.

Miller and many of his fellow historians and philosophers are promoting a crazy idea of science. Krauss has a much more sensible view. I've read the first couple of chapters of Krauss's new book, and I like it better than his previous books.

Miller is a big Einstein idolizer:
The most important scientist of the 20th century, Albert Einstein, and its most important artist, Pablo Picasso, went through their period of greatest creativity and achievements around the same time, and in similar circumstances. In 1905 Einstein discovered his theory of relativity and in 1907 Picasso discovered Les Demoiselles d’Avignon, the painting that brought art into the 20th century and that contains the seeds of cubism. Even though they did not know about each other, they were both – each in his own way – identifying connections across the so-called “two cultures" of science and art, and striving to find a solution to the question of how to represent the nature of space and time in a more satisfying manner.

At the beginning of the 20th century, it was in the air that revolutionary changes were about to occur in many fields. Yet some of the greatest thinkers of the period bucked this tide. The great French philosopher-scientist Henri Poincar√© was one of them. To my surprise, he turned out to be a common denominator between Einstein and Picasso. Both men were inspired by his book, Science and Hypothesis. Poincar√© failed because he was unable to rid himself of the notion that time was an absolute and not a relative quantity. Just the opposite of what Einstein found when he combined space and time into a single continuum – space–time – and what Picasso did in his cubism, when he represented multiple perspectives all at once on a single canvas. Einstein studied temporal simultaneity, Picasso spatial simultaneity.
Miller is quite wrong about this.

Here is what Poincare says in chapter 6 of Science and Hypothesis:
1. There is no absolute space, and we only conceive of relative motion; and yet in most cases mechanical facts are enunciated as if there is an absolute space to which they can be referred.

2. There is no absolute time. When we say that two periods are equal, the statement has no meaning, and can only acquire a meaning by a convention.

3. Not only have we no direct intuition of the equality of two periods, but we have not even direct intuition of the simultaneity of two events occurring in two different places. I have explained this in an article entitled "Mesure du Temps."
It was Poincare who combined space and time into a single continuum, and Einstein who publicly complained that he did not see any value to it.

No comments:

Post a Comment