# Light speed

1. Apr 23, 2004

### mee

Hello. Is it possible that light speed is the maximum speed because of a property of space time and not that of light? I.e. light can go the maximum speed in the universe as we know it but the maximum speed is not determined by light itself but by the nature of the fabric of space time: light is merely a measureable thing that happens to be able to go the maximum speed but is not the cause of the maximum speed? I may be ignorant but this is fun.

2. Apr 23, 2004

### AWolf

It is not only light that travels at 186,000 miles/sec.
The speed is attributed to a number of other things such as magnetism and gravity.

Maybe a better description would be the Speed of Energy, with light, as well as other things, having this as one of its properties.

There would appear to be an underlying reason as to why the speed is common.

3. Apr 24, 2004

### pallidin

To make a minor correction to your statement Awolf, the speed of gravity, though likely C, has not yet been determined.

4. Apr 25, 2004

### Antonio Lao

Without having to normalize rates and probabilities, we can say that the powers of light speed is the rate of transformation between matter and energy, matter and space, energy and space, also all the inverse transformations.

The inverse powers of light speed are the probabilities of all transformations.

5. Apr 25, 2004

### supernova

I would like to add that light does not always travel 186K m/s. It depends on the medium your talking about ie. speed of light thru space or a vacuum is 186K m/s. I am sure someone will come up with a concept that something else is faster than the speed of light...someday. I find it curious that all things are co-related but so unique.

Last edited: Apr 25, 2004
6. Apr 25, 2004

### Antonio Lao

The vacuum (the one and only absolute medium, some called it the ether or aether) is the seat of pure sourceless electric and magnetic field. The interaction between these force fields, the permittivity and permeability of the vacuum, fixed the speed of light as a universal constant of nature. To say that light speed can go higher is tantamount to saying that there is degree to becoming vacuum but the vacuum is absolute. There cannot be something more empty than the "emptiness" of the vacuum.

7. Apr 25, 2004

### AWolf

The speed of gravity has been measured with the help of gravitational lensing and allowing for a degree of error was approximated at the speed of light.

Since all matter IS energy, there are only two aspects that should really be considered. Energy and Space.
Energy travels at a fixed rate through space, so what ever properties are associated with Energy, must be a result of its interaction with Space.

It is accepted that at or near the centre of a blackhole, I'll refrain from calling it a singularity, that mass is extremely dense. This implies that the gravitational forces of a blackhole have the effect of increasing the density of mass. If mass becomes more dense, then space should also become more dense.
Relativity tells us that time slows due to gravity. What if this is due to the relative density of space.

If we produced a mass of a fixed length, lets say 186,000 miles long, and placed outside of any substantial gravitational field, light would take 1 second to travel along its length.
If we now placed this mass in a gravitational field with a relative density twice that of its original position, the mass would be compressed to a length of 93,000 miles. Light would still take 1 second to travel along its length.

The same rules should apply to the light as well as the mass.

8. Apr 25, 2004

### Antonio Lao

But space is really the square of energy. I meant one dimensional space that is. And this is the quadruple vector/scalar (outer/inner) product of quanta of length and two independent fundamental forces.

$$E^2 = r_E \times F_E \cdot r_B \times F_B$$

9. Apr 25, 2004

### AWolf

If the speed of light is determined by the properties of space/vacuum and that space/vacuum was in fact energy, would this not imply that the speed of light is determined by light itself ?
Light would become both the cause and the effect.

10. Apr 25, 2004

### Antonio Lao

I hope that if I write down Maxwell's equations in vacuum a better picture can be made whether light is the cause and effect of itself.

If all the derivatives of the permittivity and permeability are zero. Then,

$$\nabla \cdot E = 0$$

$$\nabla \cdot B = 0$$

$$\nabla \times E = - \frac{1}{c} \frac {\partial B}{\partial t}$$

$$\nabla \times B = \frac{\mu \varepsilon}{c} \frac{\partial E}{\partial t}$$

E is the electric field, B is the magnetic field, $\varepsilon$ is the permittivity and $\mu$ is the permeability, c is the speed of light.

11. Apr 25, 2004

### Antonio Lao

The speed of light c is given by

$$c = \frac {1}{\sqrt {\mu \varepsilon }}$$

where the permittivity and permeability are that of the vacuum.

12. Apr 25, 2004

### Antonio Lao

As you can see, without the existence of an electric field and a magnetic field there is no light. And EM field can exist in pure vacuum without the existence of matter.

13. Apr 26, 2004

### AWolf

From Maxwell's prospective, the photon having the properties of a wave, that would be consistant.
However from the view point of the photon being a particle, it would not.

Having properties of both wave and particle, depending how it observed, the photon is most likely to be both - a Waveicle.

Does the photon exist as a particle because of the existence of opposite but supporting electric and magnetic fields, or are these two fields the result of the photon being a particle ?

The speed of light is the most fundemental constant we know...currently.

Why is it that no matter what the source, be it a star or flashlight, the velocity is always constant ?

It would make more sense if the medium the light was travelling through was the controlling factor - the aether.
This would also explain how gravity - nothing to do with light - also travels at the same velocity, using the same medium.

If the controlling factor was the medium, then the photon could be both particulate and wave. The particle is transmitted through the medium and the wave properties the effect of the transmission.

14. Apr 26, 2004

### Antonio Lao

I forgot to mention that the electric field and magnetic field of the vacuum is inseparable. These fields can only be separated in matter, when and where charge and mass are both detectable empirically.

The pre-existence of an electric force and a magnetic force before charge and mass is what I'm driving at. these forces are the primary cause of the square of energy when quantum length is given, in turn, the square of energy defines mass and charge.

Waves are more properly a property for quantum mechanics (which include molecules, atoms, protons, neutrons, electrons and photons) while the nature of particles (quanta) is a property found in quantum field theory (where QED is the starting point and further classification of fermions and bosons).

15. Apr 26, 2004

### AWolf

Rather than only seperating in matter, it would seem more logical that all energy exists as a combination of the two fields. After all, any energy emmissions from matter consist of the recombination of the two fields back into a photon.

More likely, the two fields never seperate in matter, but matter is the result of a composite of bi-fields creating with it, its own properties dependant on the configuration of the matter.
The new matter, or bi-field system, would have its own properties in additiona to those of its components.

If you take an electron and a positron, both have charge and mass. If you fire them at each other, the result is two photons - massless and chargeless.
Where has the mass and charge gone. Nowhere. They were properties of the two systems/particles. The two particles only ever consisted of energy in different configurations.

16. Apr 27, 2004

### Antonio Lao

The destruction of an electron and a positron can also resulted in the creation of three photons. Nature always trying to outsmart the scientists.

17. Apr 27, 2004

### AWolf

With the mass of an electron being 0.5 MeV, I would assume that the mutual destuction could potentially create any number of photons with a total energy of 1 MeV.

The point is that when an electron and a positron are mutally destroyed, there are no other particles needed to account for the total energy. There are no mystical quarks missing from the equation explaining the presence of matter prior to the collision. It is just the energy of the two particles.

18. Apr 27, 2004

### Antonio Lao

I don't think there were any more decay product other than 2 or 3 photons. These works were done by Martin Deutsch in 1951. Deutsch's works led many other (include Feynman, Kendall, Ting) to receive the Nobel Prize except the man, himself. He died in August 2002 at the age of 85.