come_to_think

Reading (well, browsing --- I'm too old to follow the math):  R. Peierls, Surprises in Theoretical Physics.

As Robert Heinlein said, "a nine days' wonder is taken as a matter of course on the tenth day".  A spectacular example is what has happened to the general theory of relativity in my lifetime.  WIWAL, it was always held up as "a significant monument to the intellect of mankind".  So said R. B. Leighton in my undergraduate textbook Principles of Modern Physics.  But it only got 3 of the 800 pages in that book.  Its three famous experimental confirmations (an otherwise unexplained bit of the precession of the perihelion of Mercury, the shift in the apparent position of a star near the Sun in the sky, and the shift in frequency of a photon climbing up in the Sun's gravitational field) were tiny effects that it took strenuous efforts to observe, and that had no connection with everyday life even among physicists.  (I was gratified, back in the '60s, when the Mössbauer effect made it possible to measure the third one precisely by watching a photon climb upstairs.)  There was, however, an amusing connection (treated in Peierls's book) with the rest of theoretical physics:  When Einstein was still trying to shoot quantum mechanics down, he invented a thought experiment that seemed to mean that one could measure the size & the time of an energy transfer simultaneously.  The flaw turned out to depend on general relativity.  Hoist with his own petard!

These days, of course, general relativity is in the news every day.  We couldn't have black holes without it.  But it also is in the nonnews.  The GPS, which we would be lost without, depends on the synchrony of fantastically accurate clocks ("milliseconds per millennium", I read somewhere) in satellites.  Satellites are going at quite a clip, so in calculations involving signals from them, special relativity is required.  But they are also in free fall and significantly above us in the Earth's gravitational field, so general relativity has to be taken into account.  From being an intellectual monument, it has become something that the programmers of a public utility (in historical terms, lighthouse keepers) need to know about.  If they didn't pay attention to Einstein, busses would announce the wrong stops.

https://twitter.com/phalpern/status/897985573268463621/photo/1

This morning I was rereading a manuscript novel by an old friend of mine, of blessed memory, who was a year ahead of me at Caltech in the '50s.  It was one of two that he had sent me for comment about 10 years after we graduated, when he had become a physicist & I an assistent editor at the Physical Review.  Toward the end of the novel, the main character, who is also a physicist, goes to a summer school in Sicily, and the hot topics he learned about are listed:

current algebras, broken symmetries, resonance phenomenology, particle supermultiplets, and Regge poles

Not that I know what most of those things are, but it took me right back:  Regge poles!  What ever became of Regge poles?  Phys. Rev. was full of them in my day, but they haven't been in the news recently.  Suddenly, a thought came into my head, fifty years after:  They are poles in the scattering amplitude as a function of angular momentum continued into the complex plane.  Wikipedia has an article on Regge theory, and damned if it isn't so!  Physicists still learn about the subject, but it has become embedded in far vaster developments.

I was critical of both MSs, and in fact they never got published.  However, after he became a professor, he did publish a book, about the campus politics of his university, and it caused some scandal.  (I must look it up.)  Then he had a heart attack on the tennis court & died.  He is one of a number of people I wish I could donate my superfluous years to.

Many times a day I am reminded of things from a long time ago, as far back as childhood (70 years).  But this one was exceptional in that it was not of something I was ashamed of.