Statistical Fluctuations

Posted by jns on July 2, 2005

Abraham Pais, a physicist who wrote what is generally regarded as the definitive scientific biography of Einstein, said of his subject that there are two things at which he was “better than anyone before or after him; he knew how to invent invariance principles and how to make use of statistical fluctuations.” Invariance principles play a central role in the theory of relativity. Indeed, Einstein had wanted to call relativity the “theory of invariants”.
["Miraculous Visions: 100 Years of Einstein", The Economist, 29 December 2004.]

By way of explanation for the quotation: I came across it a few months ago and wanted to make note of it 1) because it’s quite true, and gives a remarkable insight into Einstein’s mode of thinking; and 2) because fluctuations loom large in my own way of looking at the physical world — because of my working experience in science — and because invariance principles are an interesting and important concept in physics. I’d like to discuss both of them sometime, but it will require far more presence of mind, and time, than I have to give it right now. So, I’ll preserve the quotation here and maybe get to it later.