Speed of light may have changed recently

New Scientist ^ | 6/30/04 | Eugenie Samuel Reich

[jamaksin]

Dark matter did it - not Bush!

[keithtoo]

Setterfield Hypothesis says SOL is SLOWING

http://www.ldolphin.org/setterfield/simplified.html

[Southack]

"And in March, Flambaum claimed that the ratio of different elements left over from just after the big bang suggests that alpha(s) must have been different then compared with its value today (Physical Review D, vol 69, p 063506)."

Of course, there's that other conclusion...that the Big Bang Theory is simply wrong.

Oh no, lets pretend that the speed of Light is changing rather than throw out our precious Big Bang Theory!

< /SARCASM >

[VadeRetro]

You're forgetting what CDK claims. CDK says light was 11 million times FASTER than now, 6000 years ago.

The article says light was slower and alpha was higher by a factor of 4.5 parts in 10⁸, 2 billion years ago. Wrong magnitude, wrong timescale, wrong sign.

[Gorjus]

And didn't Einstein originally just assume the speed of light as a constant?

Here's an explanation, take it or leave it as you will.

Two scientists named Michaelson and Morley conducted an experiment to measure the speed of the earth through the 'ether' - a material characteristic to space assumed to exist. After all, 'when light waves, what waves?' In other words, what propogates light through what appears to be a vacuum? The theory said there was something called ether that existed even in a vacuum.

In their experiment, they set up a right-angled apparatus, one leg of which was aligned with the direction of the earth's motion around the sun, and the other perpendicular to it. By measuring the difference in the time it took a light pulse to travel both legs, you could get a measure of the speed of the earth through the ether which is what 'waved' when a light wave went by (since the ether would drag the light along with it).

They didn't find any difference. A host of other similar experiments showed that, regardless of the circumstances, the speed of light (in a vacuum) was always the same to the limits of accuracy of the measurement.

So, Einstein didn't 'assume' the speed of light was constant. That's what the data showed.

Two other guys names Lorentz and Fitsgerald developed a relationship that quantified how much things at very high speed behaved differently than those at normal speeds. This 'Lorentz-Fitgerald contraction' was SQRT(1 - V**2/C**2).

Einstein came along and in his 'Special' theory of relativity showed that the speed of light as measured by an observer is constant regardless of his own velocity if the rate of time passes differently for the observer based on his velocity, using the Lorentz-Fitsgeral contraction to quantify the amount of change in perceived rate of time passage.

Then Einstein extended from the 'Special Theory Relativity' to the 'General Theory of Relativity' by devloping a mathematical expression for the curvature of the universe which related linear dimensions to time, with the units worked out by combining t (time) with c (speed of light). The mathematical expression is called a 'tensor', and it's as good an example of how you can't 'speak' real science without mathematics as I've ever bumped my head up against.

One good thing about the General Theory of Relativity is that it provided an explanation for gravity. It was always a challenge to conventional physics to explain action at at distance without an interaction phenomenon. How does the earth know the sun is over there pulling on us? And how does the sun manage to grab the earth and yank it around without a string between the two? The curvature of space described by solving the Einstein tensor for local conditions offers the prediction that the earth is following an equal-value (in the tensor) line around the sun even as it changes direction. In other words, the earth goes 'straight', but 'straight' is not straight in the Euclidean sense. Instead, the 'straight' travel of a body in motion is actually to follow an equipotential line in the Einstein tensor value for space.

The other good thing about the General Theory (okay, there are lots of them, but this is already a long note) is that it predicts that light itself obeys gravity, despite having no rest mass for the conventional Newtonian model to act upon. This is provable by lots of experimental data, so the General Theory gained a lot of credibility.

Now, to wrap it up, if the speed of light is not a constant, then the Einstein tensor doesn't provide a solution to the motion of bodies in space-time. There's another variable that makes it impossible to solve. There is an awful lot of observable data that would need another explanation. (Obviously, if the speed of light is almost a constant, then the Einstein tensor is almost right, and still very useful for lots of situations.)

I don't know if this data on the natural nuclear reactor proves the speed of light is variable or not, but there are lots of challenges with a totally constant, for all time, speed of light, too (as mentioned in the article), so it'll be interesting to see what happens.

[Eastbound]

"Dark matter did it - not Bush!"

Heh heh. Yer right. The unseen forces of evil seeping in through the ruptured bladder of the universe. Bush knew, but it was too late to vulcanize the hole. It was Slick Willie's fault.

[RadioAstronomer]

My chart of the nucleotides has a section on that reactor. :-)

[Dark Wing]

ping

[OSHA]

Try this Experiment (not recommended for high school students)

Completely fill the top shelf of the refrigerator with beer.

Open the door and note how long it takes to see the front cans.

Start removing the cans one-by-one until there is just a few left in the back.

Note how long it now takes to focus on the cans in the back.

Multiply the number of missing cans by the number of days (in seconds) that you are going to miss work because of the hangover.

The result is the speed of Miller Lite.

[myword]

why dark?

[AndrewC]

Speed of light may have changed recently

The speed of light, one of the most sacrosanct of the universal physical constants, may have been lower as recently as two billion years ago

I never considered 2 billion years as recent.

[Thud]

ping

[D Rider]

You're forgetting what CDK claims. CDK says light was 11 million times FASTER than now, 6000 years ago.

That's only one of the cdk theories out there. There is a much more diverse group looking that direction than 10 years ago. And from other angles.

[mcspur]

It's ok. Just wait until light gets it's second wind. Then you will really see something!!!!

[MineralMan]

"The important thing is that science has changed its story again, thus proving right all the people who say science is wrong."

What? That's just silly. The speed of light has always been variable, depending on the medium through which it travels. If that were not so, there would be no rainbows.

Perhaps you should take a moment or two and review your freshman physics book.

[null and void]

Who asked you?

;^P

[MineralMan]

"Looser!
"

Looser! Got dictionary? Loose what?

[null and void]

Wrong magnitude, wrong timescale, wrong sign.

Yeah, but other than that, a damm fine argument...

[VadeRetro]

That's only one of the cdk theories out there.

CDK refers to the decay of "c." It cannot do what it set out to do with a speed of light that used to be slower and is speeding up. You see, what it set out to do is explain why we "think" we see objects millions or billions of years old. (They are apparently millions, even billions of light-years away. There would not have been time in a young universe for light from them to reach us in any manner unless light used to be much, much faster and not long ago.) If light had slowed down dramatically very recently, that should help cram quasars into a 6000 year old universe. If light is speeding up, the problem only gets worse.

Again, if light-speed is really changing, according to this study it has speeded up a tiny fraction in 2 billion years.