David Bowman's problem must by now have led some to learn, as I did
only last semester, of a beautiful theorem in spherical geometry. This
gem came as a byproduct of taking my first GR course out of a text by
Hartle. Since David's problem is still out there, I will partially
withhold the name of the theorem's discoverer, but there is an elegant
proof that I had the good fortune to discover myself before seeing it
in another source. Reflexive Googling, so common these days, might
spoil the thrill for others.
Googling is really a rotten discoverer!
That discovery, and the fact that I could still make such "discoveries"
at my age, were exciting highlights of the course. Brian Pippard is
fifteen years older than I am. I have known him for more than thirty
five years. He retired from the Cavendish Chair at Cambridge more than
twenty years ago. Ten years ago he told me that he could no longer
understand contemporary physics, though it was quite clear to me that
he still felt he still had a command of the physics of his day. This
year he made the same comment about contemporary physics to me again,
though he still seems sharp to me. (He had a bicyle-auto collision
about twelve years ago that nearly killed him; it is quite remarkable
that he is even alive!)
Brian's feeling about contemporary physics seemed strange to me ten
years ago, which was before I retired. Now that I've been retired for
four years I am beginning to appreciate his point of view. My writing
of this piece now was initiated by my trying to read an article in
Physics Today entitled "Lorentz Invariance on Trial". I can understand
very little of this article which begins, as theoretical writings have
done from prehistoric times, by writing down a Hamiltonian. I would be
interested to know how many of the members of this group have read the
article and understood a fair bit of it. I know from what I did
understand that I would like to understand more of it, but I feel just
as impotent as Brian when I dig deeper. (I do feel "Physics Today"
should have more accessible articles!)
A good friend has recently been diagnosed as being in the early stage
of Alzheimer's disease. I have no indication that I have any reason to
worry about coming down with this malady myself, but my memory is
constantly failing me on items of obscure knowledge which were formerly
at my fingertips. I fear this is a result of my disuse of the
information in teaching. The New York Times Crossword is insufficiently
rigorous training for a physics professor. As a result, knowing of the
experience of one world class physicist, I do fear losing it. Sometimes
this fear even keeps me from sleeping.
Any other geezers out there share my feelings? What do you do to keep
sharp?