On Thursday 2003 February 27 13:55, Terry Simpson wrote:
> I heard an article on the radio about theoretical researchers suggesting
> (again) that light might not have constant speed. This would be interesting
> for metric definitions.
>
> Unfortunately I can't find a link to the article.
Terry Simpson wrote:
>
> I heard an article on the radio about theoretical researchers suggesting
> (again) that light might not have constant speed. This would be interesting
> for metric definitions.
>
> Unfortunately I can't find a link to the article.
We had a speaker in last year, Dr. Fillopenko (spelling?), who is one of the
big names in cosmology. His talk included many uses of "standard candles" (an
astronomical term and not the old candela predecessor), some of which depend
on doppler shifts and thus on the speed of light all the way back to a very
young universe. I asked how certain we were about the constancy of the speed
of light and he came to life! Turns out that this is a big discussion point
and somehow it relates to "dark energy" and the expansion of the universe.
(Don't bother asking me for an explanation!) What caused the question to
occur to me is that (I believe I have read) the general theory of relativity
predicts very slow changes in universal constants over extremely long periods
of time and that this relates to the "cosmological constant" that Einstein
first put in and then denigrated.
However, whether or not these things change, this is nothing we need to worry
about in metrology over a lifetime, or perhaps even over a millenium. It's a
very, very slow change that takes place; at least that's my impression.
Jim
--
James R. Frysinger
Lifetime Certified Advanced Metrication Specialist
Senior Member, IEEE
http://www.cofc.edu/~frysingj
[EMAIL PROTECTED]
[EMAIL PROTECTED]
Office:
Physics Lab Manager, Lecturer
Dept. of Physics and Astronomy
University/College of Charleston
66 George Street
Charleston, SC 29424
843.953.7644 (phone)
843.953.4824 (FAX)
Home:
10 Captiva Row
Charleston, SC 29407
843.225.0805
