doug (08/12/82)
reply to Don Chan replying to me about the spinning ant We are quickly leaving behind my understanding of the subject! Anyway, according to Dr. Davies, Ernst Mach attempted (unsucessfully says Davies) to promote the so-called relationist view that the spinning ant would experience inertial forces because it was spinning relative to the whole rest of the universe - a universe which cannot possibly be eliminated in any experiment! Davies says that modern physics says the fact that the ant experiences the inertial forces can be taken as "evidence of the physical reality of space." He maintains that Mach's view is not accepted by the mainstream of physics. Einstein was very influenced by Mach's thesis. The question is - if we *could* completely eliminate the rest of the universe from the experiment would the poor ant *still* experience inertial forces. Davies maintains it would.
donald (08/14/82)
Re: Doug's reply to my reply to my reply... Who is this Davies person??? As far as I can tell, many physicists accept the General Theory (although the subject is far from closed), which incor- portates Mach's Principle. In every General Relativity text I've seen (layman's and technical) the problem of Newton's bucket (a.k.a. the spinning ant) is explained in terms of Mach's Principle, i.e. the inertial forces on the water/ant are due to gravitational potential caused by the rest of the cosmos spinning. In the last century Mach's Principle was a more or less qualitative argument, but with the advent of General Relativity and Sciama in the 50's, it was put on a quantitative basis. As an aside, does everybody think that exchanges such as these replies to replies to replies should be conducted via mail? It seems that a lot of network traffic is being devoted to issues which are better solved by referring to physics texts, and perhaps not everyone is interested in spinning ants? Don Chan