Posted on 08/08/2002 9:06:23 AM PDT by Momaw Nadon
SYDNEY (Reuters) - A team of Australian scientists has proposed that the speed of light may not be a constant, a revolutionary idea that could unseat one of the most cherished laws of modern physics -- Einstein's theory of relativity.
The team, led by theoretical physicist Paul Davies of Sydney's Macquarie University, say it is possible that the speed of light has slowed over billions of years.
If so, physicists will have to rethink many of their basic ideas about the laws of the universe.
"That means giving up the theory of relativity and E=mc squared and all that sort of stuff," Davies told Reuters.
"But of course it doesn't mean we just throw the books in the bin, because it's in the nature of scientific revolution that the old theories become incorporated in the new ones."
Davies, and astrophysicists Tamara Davis and Charles Lineweaver from the University of New South Wales published the proposal in the August 8 edition of scientific journal Nature.
The suggestion that the speed of light can change is based on data collected by UNSW astronomer John Webb, who posed a conundrum when he found that light from a distant quasar, a star-like object, had absorbed the wrong type of photons from interstellar clouds on its 12 billion year journey to earth.
Davies said fundamentally Webb's observations meant that the structure of atoms emitting quasar light was slightly but ever so significantly different to the structure of atoms in humans.
The discrepancy could only be explained if either the electron charge, or the speed of light, had changed.
IN TROUBLE EITHER WAY
"But two of the cherished laws of the universe are the law that electron charge shall not change and that the speed of light shall not change, so whichever way you look at it we're in trouble," Davies said.
To establish which of the two constants might not be that constant after all, Davies' team resorted to the study of black holes, mysterious astronomical bodies that suck in stars and other galactic features.
They also applied another dogma of physics, the second law of thermodynamics, which Davies summarizes as "you can't get something for nothing."
After considering that a change in the electron charge over time would violate the sacrosanct second law of thermodynamics, they concluded that the only option was to challenge the constancy of the speed of light.
More study of quasar light is needed in order to validate Webb's observations, and to back up the proposal that light speed may vary, a theory Davies stresses represents only the first chink in the armor of the theory of relativity.
In the meantime, the implications are as unclear as the unexplored depths of the universe themselves.
"When one of the cornerstones of physics collapses, it's not obvious what you hang onto and what you discard," Davies said.
"If what we're seeing is the beginnings of a paradigm shift in physics like what happened 100 years ago with the theory of relativity and quantum theory, it is very hard to know what sort of reasoning to bring to bear."
It could be that the possible change in light speed will only matter in the study of the large scale structure of the universe, its origins and evolution.
For example, varying light speed could explain why two distant and causally unconnected parts of the universe can be so similar even if, according to conventional thought, there has not been enough time for light or other forces to pass between them.
It may only matter when scientists are studying effects over billions of years or billions of light years.
Or there may be startling implications that could change not only the way cosmologists view the universe but also its potential for human exploitation.
"For example there's a cherished law that says nothing can go faster than light and that follows from the theory of relativity," Davies said. The accepted speed of light is 300,000 km (186,300 miles) per second.
"Maybe it's possible to get around that restriction, in which case it would enthrall Star Trek fans because at the moment even at the speed of light it would take 100,000 years to cross the galaxy. It's a bit of a bore really and if the speed of light limit could go, then who knows? All bets are off," Davies said.
Another point here. Take a light wave today. Its speed c is a product of its wavelength and frequency, since you can think of it as a little sine wave flying by you with peaks and valleys. Each peak/valley pair going by is a "cycle." The "cycles-per-second" (frequency) times the physical length of a cycle must yield the overall speed of the stream of ups and downs.
Now imagine it's a Barry Setterfield universe and it's 6000 years ago. The stream is flying by 11 million times faster than the modern value. Your proposal is that the wavelength of the light is unchanged. That forces the frequency up (way up), making all the solar photons ultra-blue. (Probably gamma ray but I'm too lazy to check.)
In fact, Setterfield went the other way, deciding that solar photons are redder, not bluer. (This happens because all the photon generating reactions are operating with less mass. The universe is light as a feather but you can't tell because gravity is very much stronger than now.)
Anyway, your version still has the same problem as Setterfield's. If Adam is in the Garden of Eden on Day 6, he can't see the solar photons. His eyes are tuned to the wrong part of the band. He's blind. And he's cooking.
Well, that would depend on what the real objective is.....
;-)
Except I don't think X-ray and above penetrate the atmosphere too well. So maybe he's freezing, except he's got a real storm of alpha particles from nuclear reactions in the earth to keep him warm.
You don't think he was expecting a Nobel?
What do creationists award for the best CS paper of the year? The Gold Keyboard? (There's no laboratory required for CS work.)
I'm lazier than you, but I think you'd have cosmic rays. Whatever.
Me too. I still think it would be nice if medved switched to blue.
This is true for any medium where the dielectric constant is greater than 1.0. But this is a different case since we are talking about the dielectric constant of the vacuum. That is the problem. Could a pure vacuum have a propogation velocity that is frequency dependent? If so, you are right, things would look very odd. Everything would be rainbow. But I don't think a pure vacuum could behave that way even if the propogation factors were different than we now believe.
But I am just guessing.
RightWhale said: They shouldn't have been. Jupiter's rings were reported in Sky & Telescope in the 50s.
"The ring around Jupiter, discovered by the Voyager I spacecraft in 1979, is a thin, tenuous, almost invisible band of smokelike dust...Jupiter's ring, wherever it comes from has to be replenished regularly. The dust particles of the ring are so small (millionths of an inch) that radiation effects and the planet's magnetic field cause them to spiral down into the planet very quickly." Science 83, 3/83, p. 112. ("Mysteries: Why Do Planets Have Rings?") Are you sure you know the difference between Jupiter and Ur-
anus?
I just report. Jupiter's ring was reported in Sky & Telescope in the late 50s.
When you are refering to gamma radiation, or ultra-blue photon's you're referring to wavelenght. Inherently in the equation is a frequency based on some arbitrary value of 'c'..
It would appear, nonetheless, that changing the speed of light could have an adverse impact on optics, in that the relative index of refraction would be changed. However, according to Snell's law it is the ratio of the velocities of an incident waveform and the velocity of the waveform transmitted through a different medium (part of the incident waveform being reflected). What evidence is there that the relative index of refraction wouldn't be the same regardless of 'c'? We know that the wave frequencies of both incident and transmitted waveforms are identical, but their wavelengths change. Does this mean that if 'c' itself changes, that the relative index of refraction needs to change somehow?
If that is not so, why would Adam be blind if the speed of light (and associated frequency was higher)? Have you gone through the math yourself?
Furthermore, I see no issue with regards to functionality of diffraction with respect to the speed of light (frequency plays no part in it). Constructive and destructive interference also do not seem to be affected by differing frequencies (that behavior of light is entirely predicated on the wavelength of the light. When one examines polarization of light, it pertains to transverse electric vector viewed along the direction of the waveform propagation - polarization by reflection, refraction, selective absorption or scattering - so again frequency doesn't come into play.
Ah ha! You'll state that the frequency of light will affect Rayleigh Scattering (why the sky is blue). The closer the frequency of of the light wave is to the natural frequency of the electron of the predominant gas in the atmosphere (nitrogen), the greater the amplitude of vibration and the greater the scattering of the light wave. Thus the components of light having shorter wavelengths are scattered moreso than those with longer wavelengths. It has been shown that this scattering is proportional to the inverse of lambda to the fourth power. Even so, it appears that light is scattered according to wavelength, it actually occurs as a property of incident light (frequency) and interspersed atom's natural electon resonance (frequency). In accordance with Setterfields postulation, the fundemental resonant frequency of an atom's electrons is proportional to 'c'. Basicly I don't see a problem. Back to your Evolution pamphlets.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.