Re: Letter to Dirk Van de moortel

From: Eric Gisse (jowr.pi_at_gmail.com)
Date: 03/06/05 

Date: 6 Mar 2005 03:29:26 -0800

César Sirvent wrote:
> > An aproximation cannot be a subset of a more global theory.
>
> >Assume v << c.
>
> Oh, even then there are relativistic effects. For example, Hafele &
Keating
> experiment.

Duh.

> Still, you have an approximation. Remember than in Classical
Mechanics you
> are allowed to have speeds 10000 greater than c or more...
> So, that part of Classical Mechanics is outside your condition...

I guess I was not explicit enough for you.

In the low-velocity limit, SR reduces to Newton. If v << c, v^2/c^2 is
sufficiently close to zero that you can assume gamma = 1. Along the
same lines, another popular approximation is assuming that for theta
sufficiently small, sin(theta) = theta by taking the first part of the
series representation of the sin function. Hense "approximation".

If you wish to argue the approximation sin(theta) = theta is invalid,
or gamma = 1 for v << c, you will be fighting a very steep uphill
battle. Everyone *KNOWS* that it isn't perfect, but it is "close
enough" sometimes.

[snip]

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