speed of light decreasing?
Paul Pick
I recently read the following letter and wanted to get some opinions
on it ( I had never heard about C decreasing... ).
<********************************************>
With regards to the speed of light being non-constant. I believe
that people are refering to the paper by Norman T. and Setterfield, B., 1897
'The Atomic Constants, Light and Time'. It was originally put out by the
School of Mathematical Science, Flinders University, South Autralia.
The paper states that when all the known measurements of the speed of light
from the last 300 years are plotted out, it show the speed is not constant
but slowly declining. It seem to have leveled off at about 1960, about the
time that they switched to using the atomic clock for such measurements.
Since light is mathematically linked to many atomic processes, it is
possible that we cannot detect any change with our modern equipment.
There were also several papers published by the scientific community during
the 1930's and 40's commenting on the apparent downward trend in the
speed of light.
<********************************************>
If you would please send me your thoughts via email, instead of posting
them ( I don't read this group ), I would appreciate it.
Thanks,
- Paul
--
/---------------------------------------------------------------------\
| Paul A Pick | "Though this be madness, yet there is |
| 871...@dragon.acadiau.ca | method in't" - Hamlet, Act II, Scene II |
\---------------------------------------------------------------------/
Joel Polowin
>I would expect the speed of light to *increase* rather than decrease over
>time: as the universe expands, the fabric of space stretches, the tension
>in that fabric must be going up and as the consequence, the speed of light
>should be increasing too.
<*blink*> You mean that the luminiferous aether is approaching its elastic
limits?
Joel Polowin
pol...@silicon.chem.queensu.ca, pol...@chem.queensu.ca,
polo...@qucdn.queensu.ca
Erik Max Francis
> I would expect the speed of light to *increase* rather than decrease over
> time: as the universe expands, the fabric of space stretches, the tension
> in that fabric must be going up and as the consequence, the speed of light
> should be increasing too.
Interesting concept, but the speed of light is not merely the speed of
sound in the "fabric" of spacetime.
Erik Max Francis, &tSftDotIotE ...!uuwest!alcyone!max m...@alcyone.darkside.com
USMail: 1070 Oakmont Dr. #1 San Jose, CA 95117 ICBM: 37 20 N 121 53 W __
AGCTACTGTACGTACGTTTGCACGTATGCTGTGCAXTGCATACTGACATCGTGACTGATCTGCATGACTTGCA / \
"Omnia quia sunt, lumina sunt." (All things that are, are lights.) \__/
Robert Cain
>gus...@arp.anu.edu.au (Zdzislaw Meglicki) writes:
The quote deals with the speed of light increasing as the tension in the
"fabric" of space-time increases...
>>...the fabric of space stretches, the tension in that fabric must be going
>>up...
Can it even be thought that space-time would have a property analagous to
tension? Distortion, yes. But, tension? If the tension analog does not exist
then the thrust of Meglicki's argument is lost. Tension could be
accounted for only if space-time was fixed at a certain point and (as the
universe expanded) space-time was pulled along with the universal boundary
(like a rubber sheet being pulled in all directions). What if, as the
universe expands, matter just moves over the surface of space-time? In
other words, the sheet of rubber is already there. Then all the matter would
do is distort the "fabric," and no true global tension would result.
Zdzislaw Meglicki
|> >I would expect the speed of light to *increase* rather than decrease over
|> >time: as the universe expands, the fabric of space stretches, the tension
|> >in that fabric must be going up and as the consequence, the speed of light
|> >should be increasing too.
|>
|> <*blink*> You mean that the luminiferous aether is approaching its elastic
|> limits?
Something like that - although this is totally beyond our current understanding
of physics. If speed of light was to vary with time the reason for that
variation could be associated with the expansion of the universe. The speed
of light would then depend on some elastic (?) properties of space
itself (note that although ether was demonstrated to be unnecessary by
Einstein, it was also demonstrated to be undetectable by Lorentz, so, after
all it might exist, who knows). The expansion of the Universe could be accompanied by stretching of ether or could result from ether somehow
multiplying itself (or being injected into the Universe from the outside).
Depending on the scenario the speed of light might be affected in various
ways. If ether was to stretch, speed of light should increase, but then would
we be able to detect it in any way? - unless through observations of very
distant objects: light emitted a very long time ago would still remember
having a lower speed - it should thus arrive redshifted. Now you see that
we have another complication: the galactic redshift in this scenario would
be only partly due to the expansion of the universe and the rest of it
could be caused by the changes in the local speed of light over time.
Another way to fantasise about it would be to hypothesise that the God
particle (i.e., the Higgs field) is the modern equivalent of ether and that
it may have also some influence on the speed of light (I wonder what that
would do to the notion of covariance...). Then as the Universe expands, the
Higgs field would thin down everywhere and that might cause the speed of light
to fall, if the latter was to be, say, increasing with the density of
the Higgs field.
Lots of possibilities here...
--
Zdzislaw Meglicki, Zdzislaw...@cisr.anu.edu.au,
Automated Reasoning Program - CISR, and Plasma Theory Group - RSPhysSE,
The Australian National University, Canberra, A.C.T., 0200,
Australia, fax: +61-6-249-0747, tel: +61-6-249-0158
Zdzislaw Meglicki
|> max@alcyone (Erik Max Francis) writes:
|> Can it even be thought that space-time would have a property analagous to
|> tension? Distortion, yes. But, tension?
I did not claim that space or space-time has "tension" - but I merely
hypothesised that if speed of light were to vary in time, this could
feasibly be explained by assuming that space has also tension apart from
curvature. Note that once upon a time nobody would even think of space
being curved in the first place. It took Riemann and Einstein to introduce
this notion to physics and explain gravitation with it.
The classical Palatini action for General Relativity contains only
the fully contracted Riemann tensor. It would be a natural extension of the
theory to also add some tension terms and see what it does to the resulting
physics. Einstein's nonsymmetric field theory was an attempt to enrich
the original structure of GR and get it to describe more than just gravity.
There are various ways of doing that. For example you can add one more
dimension: this is the Klein-Kaluza theory and it actually works.
You can also make the basic tensor of the theory (the metric) nonsymmetric.
It's been shown only relatively recently 70s and 80s (e.g., Klotz and
Johnson) that such a theory can work too and it even predicts a very
interesting cosmology. Still, nowadays such attempts are just a mathematical
curiosity, since it is currently *believed* that the physical world does
not work like that. Alas, the views of the physicists tend to follow
various fashion trends and every now and then they take a rapid turn.
It may yet turn out in due course that there are many ways to describe
physical phenomena apparently different and incompatible and yet
in some way equivalent. If Einstein knew about solitons and chaos in
classical systems he would probably be very encouraged.
Eric Cain
misinterpreted you viewpoint (the reason for the misinterpretation could be
because I was responding to a quote from your article rather than the whole
thing).
-E.Cain Where IS the particle when no one is looking?
/\ It definitely isn't in Kansas.
I<>I (4n+2)pi e-
\/
Phil Gibbs
>
> I recently read the following letter and wanted to get some opinions
> on it ( I had never heard about C decreasing... ).
>
> <********************************************>
>
> With regards to the speed of light being non-constant. I believe
> that people are refering to the paper by Norman T. and Setterfield, B., 1897
> 'The Atomic Constants, Light and Time'. It was originally put out by the
> School of Mathematical Science, Flinders University, South Autralia.
> The paper states that when all the known measurements of the speed of light
> from the last 300 years are plotted out, it show the speed is not constant
> but slowly declining. It seem to have leveled off at about 1960, about the
> time that they switched to using the atomic clock for such measurements.
> Since light is mathematically linked to many atomic processes, it is
> possible that we cannot detect any change with our modern equipment.
> There were also several papers published by the scientific community during
> the 1930's and 40's commenting on the apparent downward trend in the
> speed of light.
>
It may surprise many to be told that if you propose a varying speed of
light and then try and predict an observable affect resulting from it
you will not find one.
To be more precise take the combined equations of general relativistic
electromagnetism and gravity. In these equations the constant "c" known
as "the speed of light" will appear in several places, (assuming it has
not already been removed by setting it to one). Now replace c in the
equations by any (positive C2) function of space time you care to think
of. What you will find is that this function can be absorbed into the
gauge invariance of the gravitational field metric. It is therefore
impossible to find any observable effect of the speed of light changing.
ph...@strauss.eurocontrol.fr = Phil Gibbs
_____ __________ __________ __________ __________ __________ __________ ________
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____\_\/ /_____\_\/ /_____\_\/ /_____\_\/ /_____\_\/ /_____\_\/ /_____\_\/ /____
________/__________/__________/__________/__________/__________/__________/_____
"My thoughts are not your thoughts, |
neither are your ways my ways. |
As the heavens are higher than the Earth, | "Bullshit!" Anonymous
so are my ways higher than your ways |
and my thoughts than your thoughts" God. |
Matt McIrvin
>It may surprise many to be told that if you propose a varying speed of
>light and then try and predict an observable affect resulting from it
>you will not find one.
>To be more precise take the combined equations of general relativistic
>electromagnetism and gravity. In these equations the constant "c" known
>as "the speed of light" will appear in several places, (assuming it has
>not already been removed by setting it to one). Now replace c in the
>equations by any (positive C2) function of space time you care to think
>of. What you will find is that this function can be absorbed into the
>gauge invariance of the gravitational field metric. It is therefore
>impossible to find any observable effect of the speed of light changing.
It depends, of course, on what you hold constant. If you use
atomic units in which the speed of light is the inverse of the fine
structure constant, then by "varying the speed of light" you're
actually varying the fine structure constant, and a particle
physicist like me would describe that as "varying the strength
of electromagnetic coupling" instead. This is, of course, different
from what you've described, which would indeed have no effects.
Twiddling constants of nature is a tricky business.
--
Matt 01234567 <-- The original Indent-o-Meter
McIrvin ^ Someday, tab damage will light our homes!
benjamin franz
Eh? I know that a number of QM equations depend in high order non-linear
ways on the value of C. (C to fractional powers and sixth or eighth
powers). Dammit - where did I leave that reference...
Here it is:
_V. S. Troitskii, "Physical Constants and the Evolution of the Universe", in
Astrophysics and Space Science, Vol. RN>139, pp. 389-411, Dec. 1987._
He was exploring the theoretical consequences of the speed of light
varying slowly over the lifetime of the universe. The value of variation he
came up with as being not inconsistent with the universe as we see it was only
2 centimeters per second per year.
Phil Gibbs
In article <2jqo15$i...@u.cc.utah.edu>, bf6...@u.cc.utah.edu (benjamin franz) writes:
> Phil Gibbs (ph...@eurocontrol.fr) wrote:
> : In article <1994Feb1.0...@relay.acadiau.ca>, 871...@dragon.acadiau.ca (Paul Pick) writes:
> : >
> : > I recently read the following letter and wanted to get some opinions
> : > on it ( I had never heard about C decreasing... ).
> : >
>
> : It may surprise many to be told that if you propose a varying speed of
> : light and then try and predict an observable affect resulting from it
> : you will not find one.
>
> : To be more precise take the combined equations of general relativistic
> : electromagnetism and gravity. In these equations the constant "c" known
> : as "the speed of light" will appear in several places, (assuming it has
> : not already been removed by setting it to one). Now replace c in the
> : equations by any (positive C2) function of space time you care to think
> : of. What you will find is that this function can be absorbed into the
> : gauge invariance of the gravitational field metric. It is therefore
> : impossible to find any observable effect of the speed of light changing.
>
> Eh? I know that a number of QM equations depend in high order non-linear
> ways on the value of C. (C to fractional powers and sixth or eighth
> powers). Dammit - where did I leave that reference...
>
... a moments pause ....
Ok, I am going to try and wriggle out of this one as follows:
I mentioned General Relativity, you mentioned Quantum Mechanics. The two
have not yet been unified into a complete theory. When they are it is
likely that the theory will predict the masses of particles and when you
write down the equations for the masses you will see that the constant
c appears in the equations. The equations you mention in QM all have
various particle masses in them so there are hidden ways in which the
constant c appears and, of course, these cancel the visible ones.
( ( (: ( ( ( ( ( ( ( ( ( ( ( ( (
) ) ) ) ) ) ) ) ) :) ) ) ) ) ) )
( ( ( ( (: ( ( ( ( ( ( ( ( ( ( (
) ) ) ) ) ) ) ) ) ) ) ) ) :) ) )
ph...@strauss.eurocontrol.fr = Phil Gibbs
Richard A. Schumacher
and ignoring error bars to get his desired result. Even the Institute for
Creation Research, which would dearly love to find proof that the universe
is young, has withdrawn acceptance of Setterfield's work.
Mark Hopkins
for God's sake! That like saying the "speed of mile" (5280 feet per mile)
can change.
Things that change or not change: pure numbers, like the fine structure
constant (which, by the way, what most people are REALLY referring to
when talking about c changing).
###
Hartmut Frommert
ma...@freenet.uwm.edu (Mark Hopkins) writes:
>The speed of light can't increase or decrease, it's a conversion factor,
>for God's sake! That like saying the "speed of mile" (5280 feet per mile)
>can change.
Though the natural constant "c" which is usually called the vacuum light
velocity (or speed) can only be changed by re-definition of units (as any
conversion factor), the (actual) speed of (the propagation of) light
(photons !) is NOT constant, e.g. in a gravitational field (see any textbook
on elementary General Relativity).
-
Hartmut Frommert | Russia HAS a Space Station !
<phf...@nyx.uni-konstanz.de> | Mars Observer 2 would have survived.
john baez
>Though the natural constant "c" which is usually called the vacuum light
>velocity (or speed) can only be changed by re-definition of units (as any
>conversion factor), the (actual) speed of (the propagation of) light
>(photons !) is NOT constant, e.g. in a gravitational field (see any textbook
>on elementary General Relativity).
This is darn misleading. The speed of light is constant in GR, it's
just that the spacetime the light is moving around in is a bit wiggly.
Of course, one *could* think of it the way you suggest, but one would
have to say, not just that the speed of light was different in a
"gravitational field," but that all other laws of physics were different
too, in a fairly complicated manner.
Hartmut Frommert
>phf...@nyx.uni-konstanz.de (Hartmut Frommert) writes:
>>[..] the (actual) speed of (the propagation of) light
>>(photons !) is NOT constant, e.g. in a gravitational field [..]
>This is darn misleading. The speed of light is constant in GR, it's
>just that the spacetime the light is moving around in is a bit wiggly.
>Of course, one *could* think of it the way you suggest, but one would
>have to say, not just that the speed of light was different in a
>"gravitational field," but that all other laws of physics were different
>too, in a fairly complicated manner.
Ok, that's a relative standpoint :)
Of course there's a straightforward way to identify the (semiclassical)
trajectories of light (you know that all, of course): Riemannian Null
geodesics, so the constant "4-length" Null for the 4-velocity. Splitting in
3+1 (space+time), both the choice of coordinates and the gravity-dependent
metric components enter, and may be adjusted so that "|v_3|=c". But this is
usually not done, e.g.
Schwarzschild coordinates (radial) -> |v_3| = [1 - 2(G/c^2)(M/r)] c,
linearized theory -> |v_3| = [1 - 2 |U_N|] c
(U_N: Newtonian gravitational potential). As you seem to propose, one may
however view these values as indicators for the insufficience of the
coordinates under consideration, and of the 3+1 splitting.
Dave Griffiths
Not sure I understand you. It takes a certain amount of time for a light
pulse to leave me, hit the moon, and bounce back again. I could measure
that time in heartbeats (just to get away from more confusion over what a
"second" is). Let's say it normally takes eight heartbeats. Is it possible
for the speed of light to halve, such that the round trip now takes
sixteen heartbeats, or does the speed of light "cancel out" in all
equations so that although the light is going slower, the atoms and
electrons that make up my body are communicating more slowly resulting in
my heart beating slower resulting in no perceivable difference?
In other words, is the speed of light a bit like Pi?
Dave Griffiths