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- Path: sparky!uunet!dtix!darwin.sura.net!jvnc.net!nuscc!matmcinn
- From: matmcinn@nuscc.nus.sg (Mcinnes B T (Dr))
- Newsgroups: sci.physics
- Subject: Re: Aristotle and the Modern Physicist
- Message-ID: <1992Jul24.024619.28944@nuscc.nus.sg>
- Date: 24 Jul 92 02:46:19 GMT
- References: <mcirvin.711906105@husc8>
- Organization: National University of Singapore
- Lines: 27
-
- "you can't deny that the metric affects where they end up going..."
- I realise that I may have been a little unfair to SOME modern
- physicists. I am aware, too, that not everybody takes the "exchange of
- virtual particles" bit very seriously. But I do claim that many people
- think of gravitation as an "interaction". Which it is NOT; this being
- the main point of GR. Now without getting too philosophical about it, I
- suppose that when people say that two things "interact", they mean that
- these things end up doing something that they otherwise would not. I am
- pretty sure that, though they may protest otherwise, a lot of people
- privately think of gravitation as just another "interaction", albeit one
- with an unusually complicated classical version. But this is simply
- wrong: as Aristotle said, the Earth goes around the Sun on an
- approxiamtely elliptical orbit NOT because it is being "forced" to do
- so, NOT because it is"interacting" with the Sun, but rather because it
- is NOT interacting with the Sun. To ask, "why does the Earth go around
- the Sun?" is precisely analogous to asking Newton or Galileo why a free
- particle moves in a straight line at constant speed. What would you have
- it do? I fear...correct me if I am mistaken... that when you say that
- the "metric affects where they are going" you are thinking of the metric
- tensor as a thing that lives on Minkowski space: the particle would
- really like to follow the Minkowski geodesics, but the metric compels it
- to go elsewhere. Would you say that the Minkowski metric "interacts"
- with free particles in Minkowski space and "forces" them to move along
- straight lines ["inertons"!]? No? Well, if you do not wish to say it of
- Minkowski space, then don't say it of any other spacetime. "Gravity" was
- all a mistake, resulting from our ignorance of spacetime curvature. How
- does one quantize a mistake?
-