Re: Evidence for "Big Bang Theory"

Carl J Lydick (carl@SOL1.GPS.CALTECH.EDU)
26 Apr 1995 03:53:53 GMT

In article <3nk6f7$>, (Dan Drake) writes:
=>The current consensus is that photons do not have mass, but I've heard of
=>ongoing research that asserts that photons may have a miniscule amount.
=> james
=Does anyone have a reference for this? It is literally incredible and
=completely inconsistent with fundamental physics. I think.

A scientific theory is evaluated on how closely it matches observations, not
the other way around.

=Light travels at the speed of light (amazing!) and by simple relativity
=theory can not have a non-zero rest mass.

The speed of light in a vacuum is constant, TO WITHIN THE PRECISION OF OUR
MEASUREMENTS. Our measurements, needless to say, do not have perfect
precision. However, the working assumption, based on our observations, is that
the speed of light in a vacuum is, indeed, constant. There's still the
possibility that that working assumption is false. That's one reason why
whenever someone comes up with a more precise way of measuring light speed,
that technique is used to check to see whether, with the higher precision,
variations in light speed can be detected. Thus far, they haven't been.
Howeveer, if such variations in light speed were found, then one of the
fundamental premises of the special theory of relativity would be invalid, as
would its prediction that photons have zero rest mass.

Yes, the special theory of relativity has made quite a few very good (and
counterintuitive) predictions, and we've yet to find its predictions being
violateed in situations where the assumptions of special relativity (inertial
frame of reference in flat space-time; if you violate either of these
assumptions, you've got to use general relativity instead of special
relativity) hold. On the other hand, the same thing could be said, in the
mid-nineteenth century, of Newtonian mechanics (well, actualy, I'm not sure
exactly when the precession of Mercury's orbit became a problem for Newtonian

Disclaimer: Hey, I understand VAXen and VMS. That's what I get paid for. My
understanding of astronomy is purely at the amateur level (or below). So
unless what I'm saying is directly related to VAX/VMS, don't hold me or my
organization responsible for it. If it IS related to VAX/VMS, you can try to
hold me responsible for it, but my organization had nothing to do with it.