Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!harpo!seismo!hao!hplabs!sri-unix!gwyn@brl-vld From: gwyn%brl-vld@sri-unix.UUCP Newsgroups: net.physics Subject: Re: Re: eV Revisited - (nf) Message-ID: <16831@sri-arpa.UUCP> Date: Sat, 18-Feb-84 20:13:08 EST Article-I.D.: sri-arpa.16831 Posted: Sat Feb 18 20:13:08 1984 Date-Received: Tue, 21-Feb-84 04:04:59 EST Lines: 36 From: Doug Gwyn (VLD/VMB)The reason you don't get the same conversion factor for mass<->distance working it out two ways is that in one of them you have tried to mix a relativistic fundamental equivalence (E=mc^2) with a Newtonian formula (E=Fs) that is not appropriate. One should not just toss a bunch of formulas together at random; your equations should be describing some single THING or SITUATION in order for them all to apply at once. It is true that if sufficient care is taken one can reduce the number of "fundamental" physical units (standards of measurement). Instead of separate time and space units, one can use the fundamentals of special relativity to relate the units to each other via the speed of light. (A careful treatment of this would require discussion of canonical forms of the metric tensor and their physical interpretation.) Similarly, other types of physical quantity have fundamental relations that let one interconvert what appear to be different aspects of an object or situation. The interesting question is, how FEW independent standards of physical measurement are there? From the standpoint of geometrical theories of physics such as relativity, there would appear to be only one basic unit (could measure any non-pure-number attribute, e.g. unit of length, or of mass, or of time, ...). Amazingly, according to Einstein-Schr"odinger unified field theory, there are NO inpendendent measurement standards. This is a consequence of the closure of the theory; it is sometimes phrased "the universe is self- gauging". A more usual way of looking at this would be to allow one unit (say length) in terms of which the natural curvature of the universe would be expressed (the reciprocal of a very large number, using "laboratory size" units), instead of the theoretically preferable approach of using the inherent curvature as a "natural" unit. (In this theory, the local metric is intimately related to the large-scale structure of space-time via a non-zero CONSTANT that spontaneously occurs in the development of the theory [think of it as a constant of integration if you wish].)