Speed of light is limited by what?

[EWright]

OK, let's get to the heart of the matter here. The speed of light is limited by what physical property of the physics of the universe???

[Erasmus00]

OK, let's get to the heart of the matter here. The speed of light is limited by what physical property of the physics of the universe???

 

An excellent article by N. David Mermin, titled "Relativity without Light" appeared in the February, 1984 edition of the American Journal of Physics. In it, he shows that the first postulate of relativity (i.e., the laws of physics are the same in any inertial frame) implies a universal speed limit. This constant can be discovered through careful experiments.

 

Also, Maxwell's equations show that interacting E and B fields can create travelling wave at speed c. Given that these equations are valid in any inertial frame, it implies that these em waves (light) travel at speed c, regardless of the frame. This constant can be built out of quantites known as the permeability and permittivity of space.

 

These are just two of I'm sure many avenues of thought that lead to the existance of a universal speed limit, i.e. speed of light.

-Will

[EWright]

Perhaps I wasn't clear. I am not arguing that current physics implies the speed of light barrier. I am asking what specific physical property of physics or the universe IMPOSES the limit at this specific speed. I can answer this; can any of you? SR bases everything around this notion but does not account for the cause of it, or at least not that I have read. My theory does identify the physical property(ies) that limit light and gravity to this speed, so to speak. I am interested in the explanation of current physics for the limiting factor, as I am admittantly ignorant of the current explanation.

[Erasmus00]

Perhaps I wasn't clear. I am not arguing that current physics implies the speed of light barrier. I am asking what specific physical property of physics or the universe IMPOSES the limit at this specific speed. I can answer this; can any of you? SR bases everything around this notion but does not account for the cause of it, or at least not that I have read. My theory does identify the physical property(ies) that limit light and gravity to this speed, so to speak. I am interested in the explanation of current physics for the limiting factor, as I am admittantly ignorant of the current explanation.

 

The electric properties I cited above define the speed of light quantity. Also, if you are not willing to discuss your theory, stop bringing it up.

-Will

[EWright]

The electric properties I cited above define the speed of light quantity. Also, if you are not willing to discuss your theory, stop bringing it up.

-Will

 

I'm working on completing and revising it right now. I hope to discuss it soon enough, but probably not directly in this forum. However, the more I learn about physics, the more I see ways to tie my theory into such factors at quantum theory, etc.; so it seems to be a growing task.

[EWright]

The electric properties I cited above define the speed of light quantity. Also, if you are not willing to discuss your theory, stop bringing it up.

-Will

 

EM properties, eh? Hmmm... then does gravity share these exact same properties, causing it to travel at the same speed as light? :xx: I think not. What property then causes gravitational waves to assume the same speed as light? I'll let you answer before giving you a hint.

[UncleAl]

1) Permeability and permittivity of the vacuum

 

http://scienceworld.wolfram.com/physics/PermeabilityofFreeSpace.html

http://scienceworld.wolfram.com/physics/PermittivityofFreeSpace.html

 

2) Scharnhorst effect

 

http://arXiv.org/abs/gr-qc/0107091

http://arXiv.org/abs/quant-ph/0010055

Phys. Lett. B236 354 (1990)

Phys. Lett. B250 133 (1990)

J Phys A26 2037 (1993)

Andrew Gould (Princeton, Inst. Advanced Study). IASSNS-AST-90-25

[EWright]

1) Permeability and permittivity of the vacuum

 

http://scienceworld.wolfram.com/physics/PermeabilityofFreeSpace.html

http://scienceworld.wolfram.com/physics/PermittivityofFreeSpace.html

 

2) Scharnhorst effect

 

http://arXiv.org/abs/gr-qc/0107091

http://arXiv.org/abs/quant-ph/0010055

Phys. Lett. B236 354 (1990)

Phys. Lett. B250 133 (1990)

J Phys A26 2037 (1993)

Andrew Gould (Princeton, Inst. Advanced Study). IASSNS-AST-90-25

 

I looked at your links unc; can you explain it in plain english since I don't have the cash to pursue another degree?

[Erasmus00]

EM properties, eh? Hmmm... then does gravity share these exact same properties, causing it to travel at the same speed as light? :xx: I think not. What property then causes gravitational waves to assume the same speed as light? I'll let you answer before giving you a hint.

 

Postulate one of SR implies a speed limit that is a fundamental contant of nature. Thus far, the only way to get a numerical value for this speed is to measure it, which we have done. Having established this speed limit, it seems natural that forces travel at this max. speed. This speed limit then, sets the electro/magnetic properties of space.

 

Now, as to your "I don't want to pay for another degree" comment. You don't have to. However, if you want to discuss physics, you have to learn some physics. Someone else on the forum posted a link to these books http://www.lightandmatter.com/. Start here, learn some intro physics. If you know calculus already, start with "Intro to Mechanics" by Kleppner and Kolenkow. You'll find they even have a nice treatment of SR at the end.

-Will

[EWright]

Postulate one of SR implies a speed limit that is a fundamental contant of nature. Thus far, the only way to get a numerical value for this speed is to measure it, which we have done. Having established this speed limit, it seems natural that forces travel at this max. speed. This speed limit then, sets the electro/magnetic properties of space.

-Will

Your "science" just went down the tubes. See below and then extrapolate.

 

Postulate:

1. To assume or assert the truth, reality, or necessity of, especially as a basis of an argument.

2. To assume as a premise or axiom; take for granted.

3. Something assumed without proof as being self-evident or generally accepted, especially when used as a basis for an argument.

 

Axiom:

1. A self-evident principle or one that is accepted as true without proof as the basis for argument; a postulate.

[Qfwfq]

OK, let's get to the heart of the matter here. The speed of light is limited by what physical property of the physics of the universe???

The Minkowskian geometry of space-time.

[Erasmus00]

Your "science" just went down the tubes. See below and then extrapolate.

 

Postulate one of SR, the one you state flushes "my" science down the toilet, states that the laws of physics should be the same in any inertial frame. If you can demonstrate that postulate false you'll overturn quite a few branches of physics.

-Will

[UncleAl]

Empirical magnetic (permeability) and electrical (permittivity) properties of the vacuum set lightspeed to a given value through Maxwell's equations. We must then also postulate that space is homogenous (the same everywhere) and isotropic (the same in every direction) over all time (homogeneity of time). This all gets lumped into Lorentz invariance. If you find a reproducible instance of Lorentz symmetry breaking, all bets are off. Three comments,

 

1) Folks are looking for Lorentz violations, e.g.,

 

http://www.physics.indiana.edu/~kostelec/faq.html

http://www.npl.washington.edu/eotwash/publications/cpt01.pdf

 

2) General Relativity does not contain globally conserved properties. Locally we expect conservation of mass-energy, linear and angular momenta to be valid to very great sensitivity.

 

Despite all the potential slack in the system, observational physics remains utterly rigorous to date in all venues at all scales at all redshifts. Lightspeed appears identical within experimental error in all elsewheres and all elsewhens. The Scharnhorst effect has never been observed.

 

3) Uncle Al is currently running an Equivalence Principle (and Lorentz Invariance) violation experiment with an academic group in PR China; qz.pdf below. After some three weeks of running we know that EP parity violation is not more than 10 parts-per-trillion difference/average. The run terminates in mid-September with an overall sensitivity of 0.1 parts-per-trillion.

[Raelian1]

Light is not the fastest entity in the universe. There are things that go faster than light.

[infamous]

Light is not the fastest entity in the universe. There are things that go faster than light.

Would you like to expound upon that idea?

[Bobby]

Perhaps I wasn't clear. I am not arguing that current physics implies the speed of light barrier. I am asking what specific physical property of physics or the universe IMPOSES the limit at this specific speed. I can answer this; can any of you? SR bases everything around this notion but does not account for the cause of it, or at least not that I have read. My theory does identify the physical property(ies) that limit light and gravity to this speed, so to speak. I am interested in the explanation of current physics for the limiting factor, as I am admittantly ignorant of the current explanation.

 

 

The speed of light is equal to the square root of the permittivity of free space and the permeability of free space. The permittivity of free space is essentially a restatement of Coulomb's Law which gives the force between two electric charges. The permeability of free space is a restatement of the definition of an Amphere. Since magnetism is associated with electric charge, it would not be incorrect to say that the speed of light is determined by the force (strength) of electric charge.

 

The other consideration is the medium through which the light is traveling. Some substances such as water and glass slow the over all speed of light because the light (photons) are continually being absorbed and emitted and this takes some time. Depending on how you want to look at it, gravity is also a medium. This medium would not be the same as glass or water because the photons are not being absorbed and emitted, rather they are being generated and regenerated due to the interplay between electric fields and magnetic fields.

 

It appears to me that the speed of light is always determined by the magnitude of the electric force and the medium through which it travels. In the case of "empty" space, electric charge seems to be the measurement of electric charge within a gravitational field.

[EWright]

The speed of light is equal to the square root of the permittivity of free space and the permeability of free space. The permittivity of free space is essentially a restatement of Coulomb's Law which gives the force between two electric charges. The permeability of free space is a restatement of the definition of an Amphere. Since magnetism is associated with electric charge, it would not be incorrect to say that the speed of light is determined by the force (strength) of electric charge.

 

The other consideration is the medium through which the light is traveling. Some substances such as water and glass slow the over all speed of light because the light (photons) are continually being absorbed and emitted and this takes some time. Depending on how you want to look at it, gravity is also a medium. This medium would not be the same as glass or water because the photons are not being absorbed and emitted, rather they are being generated and regenerated due to the interplay between electric fields and magnetic fields.

 

It appears to me that the speed of light is always determined by the magnitude of the electric force and the medium through which it travels. In the case of "empty" space, electric charge seems to be the measurement of electric charge within a gravitational field.

 

Hmmm... grreat posts so far Bobby. Relatively easy to understand and you actually address the issue at hand, unlike many responses.

 

I am however, still not satisfied with the idea that there are properties of space that limit the speed of light. I understand that light travels at different speeds through water, glass or a gravitational field, but that is not the question at hand.

 

 

The above statement comes about the closest I've heard to making sense. However, if light is determined by properties of its own electomagnetism, that has nothing to do with the permiability of empty space. I would have to say the same for restructuring of formulas pertaining to the Amphere or Coulomb's law (are we talking inverse square here?). Since physicists still don't know exactly what empty space is made of yet, it doesn't make sense to say that there is a property of space itself that limits the speed of light.