- #1

cDimino

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http://arxiv.org/abs/astro-ph/0305457

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- Thread starter cDimino
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- #1

cDimino

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http://arxiv.org/abs/astro-ph/0305457

Thanks

- #2

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The author in my opinion does make a few good philosophical points, but it would be unwise to treat his theory as being a good representation of reality.

As far as the speed of light goes, according to current theory (General Relativity) wherever you are, the speed of light is 'c', and wherever you go, the speed of light will also be c. You may think that the speed of light is not equal to 'c' someplace else far away from you, but if you actually go there and measure it, you'll find that it's equal to 'c'.

This may sound odd, but that's the way it works according to current theory. Details of calculating the "apparent speed of light" far away from you are highly technical, and depend on the exact coordinate system used. Philosophically, one can view the speed of light as being always constant, and the coordinate systems themselves as being warped - this is more or less the standard view.

Mathematically, given a pre-defined coordiante system, the path of light must obey certain equations, called geodesic equations, the path that light takes is one particular form of geodesic called a "null geodesic".

- #3

ohwilleke

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- #4

turbo

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There is a caveat here, if we believe that quantum theory is correct. Quantum physics predicts that the vacuum of "empty space" is anything but empty and is in fact a seething field of virtual particle pairs. If light has to cross this medium and the medium's density is NOT absolutely uniform, we must have to consider that the speed of light in a "vacuum" is not absolute and is not constant. Light slows and is refracted as it enters denser transmissive media, in accord with classical optics.ohwilleke said:

If "empty" space is not empty, the "speed of light in a vacuum" is a theoretical ideal that can never be met, and the universe is a lot messier than envisioned in GR.

- #5

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turbo-1 said:There is a caveat here, if we believe that quantum theory is correct. Quantum physics predicts that the vacuum of "empty space" is anything but empty and is in fact a seething field of virtual particle pairs. If light has to cross this medium and the medium's density is NOT absolutely uniform, we must have to consider that the speed of light in a "vacuum" is not absolute and is not constant. Light slows and is refracted as it enters denser transmissive media, in accord with classical optics.

If "empty" space is not empty, the "speed of light in a vacuum" is a theoretical ideal that can never be met, and the universe is a lot messier than envisioned in GR.

But I could also play the game in a different way. You are making an explicit assumption of a normal, dispersive medium. There's nothing here to indicate that this "exotic medium of virtual particles" cannot be an anomolous, non-linear medium. We already have such stuff today with regular materials, exhibiting negative permitivity and permeability. Such medium doesn't follow the normal rules that light (at least the phase velocity) has to slow down in a medium.

Furthermore, your scenario immediately would need to reconcile with the fact that we DO measure a constant value for c. If there are such variations due to what you describe, one would expect the value of c to deviate by a very large amount the further that light has travelled. Has this been observed? Over a large frequency spectrum?

Zz.

- #6

Berislav

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