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From: ethan@utastro.UUCP (Ethan Vishniac)
Newsgroups: net.sf-lovers
Subject: Re: FTL Travel
Message-ID: <436@utastro.UUCP>
Date: Sun, 28-Jul-85 17:24:36 EDT
Article-I.D.: utastro.436
Posted: Sun Jul 28 17:24:36 1985
Date-Received: Thu, 1-Aug-85 21:45:25 EDT
References: <2702@topaz.ARPA> <1622@orca.UUCP> <813@ncoast.UUCP>
Organization: U. Texas, Astronomy, Austin, TX
Lines: 32

> I think it's legitimate to throw up my hands
> | and say that infinite mass is impossible.
> +---------------
> 
> But one message on here said that the mass equation was just a way of keeping
> F=ma legit at high speeds.  So?  What if it isn't so?  What if the physicists
> did it to themselves again -- preserved their prejudices and thereby got the
> wrong result?
> 
> Any comments?
> -- 
> Brandon Allbery, Unix Consultant -- 6504 Chestnut Road, Independence, OH 44131

Sure.  The theory of relativity says that it takes infinite energy to 
accelerate a particle up to the speed of light.  Whether one chooses to
regard this as infinite mass as well is a matter of formalism.  In many ways
it is convenient to restrict one's definition of mass to "rest mass", but
this is a trivial point.  The important point is that the effects of
SR can be seen, and are seen, in particle accelerators whenever the particle
energy becomes comparable to the particle rest mass.  This shows up both
in time dilation (the apparent half-life of particles increases) and in
the increasing amount of energy necessary to add to a particle's velocity.
SR is certainly correct in the sense that Newtonian dynamics is correct, ie.
correct in the regime in which it is normally applied.  FTL enthusiasts had
better hope for an extension of physics that allows FTL, not a revocation
of SR.
-- 

"Don't argue with a fool.      Ethan Vishniac
 Borrow his money."            {charm,ut-sally,ut-ngp,noao}!utastro!ethan
                               Department of Astronomy
                               University of Texas