weemba@brahms (Matthew P Wiener) (11/08/86)
Summary: Expires: Sender: Distribution: Keywords: In article <240@sri-arpa.ARPA> KFL@MX.LCS.MIT.EDU writes: > I doubt that it is possible to design an experiment whose results could > require reverse causality for their explanation. [Frank Adams] > > I don't think there is any reverse causality, and if there is, I >think it is much more likely to be discovered by peering at an >oscillosope in a high energy physics lab than by peering at cards with >mystical symbols on them by candlelight, Here here! > HOWEVER, I think experiments >CAN and HAVE been designed which would require reverse causality to >explain a possible outcome of. Could you go into detail on this? That "require" seems a bit strong. I would say that Frank Adams' assertion is on par with Poincare's famous claim that given a choice between a physical theory using non-Euclidean geometry and its mathematically equivalent embedding in a Euclidean space, physicists would of course opt for the latter. I for one cannot think of a physical theory where reverse causality is the preferable explanation. Nor have I tried. > Saying that no such experiment is >possible is saying that belief in forward-only causality is non- >scientific. All scientific beliefs are in principle falsifiable by >experiment. Yes and no. I'd say a lot of so called "scientific beliefs" are in the category of semantic conventions. For example, does the earth go around the sun, or vice versa, or around their mutual center of gravity, etc? All those questions are answered "yes" in an appropriate frame of refer- ence. One can trivially come up with coordinate systems where the earth is "hollow", etc. The modern attitude is that while certain frames are clearly more natural, and our terminology reflects those frames, the ac- tual physical "reality" lies above particular reference frames. According to Martin Gardner, people used to get in intense flame wars over the question of whether the moon rotates or not. Willard Quine and others would go further and maintain that NO scientific beliefs are falsifiable in principle. ucbvax!brahms!weemba Matthew P Wiener/UCB Math Dept/Berkeley CA 94720 "Do not believe astrophysical observations until confirmed by theory."