What limits the speed of light?

Answer 1

The speed of light is determined by the electrostatic permittivity and the magnetic

permeability of free space. That's why it was possible to predict it long before it

was measured. Once you have those two numbers for free space, the speed of

light is the square root of the reciprocal of their product.

Answer 2

if a ray of light is travelling,That ray can be divided into three parts.

1. Intensity part
2. The part that maintains the speed of light
3. The part that maintains the wavelength/frequency of light

• The intensity part supplies a constant energy instantaneously into the part that maintains Speed of lightand the part that maintains the wavelength.....
• Hence as the gravitational force increases,Intensity of light decreases and at last the ray vanishes but there is no change in its speed of light....
• But if we consider any medium other than vacuum,There is constant change in the energy supplied by the intensity part to the speed of light part as a result of which,speed of light changes which results in change of frequency but to maintain frequency constant, its wavelength alters....

At last I conclude that the speed of light is limited to a constant value as the energy supplied by the intensity part of the light ray to the speed of light part is a constant for a given medium.

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OK. Very nice. Try this:

The speed of any wave is determined by the properties of the medium through which

it's traveling.

The speed of sound ... a mechanical wave ... is determined by the mechanical

characteristics of the medium, mainly the density: Sound travels slowest in thin

air, faster in normal air, faster in water, faster in steel and rock.

The speed of light ... and all other electromagnetic waves ... is determined by the

electrical characteristics of the medium. These are quantities that most people have

never heard of. But if you look up the static permeability of vacuum and the magnetic

permittivity of vacuum, multiply those two numbers, take the square root of the product,

and then do 1 over that number (the reciprocal), you come out with a number that

you recognize as the speed of electromagnetic waves in vacuum ... determined by

the electrical properties of that medium.

Answer 3

Light (and the other electromagnetic things) is a traveling combination of electric

and magnetic fields. Its speed is determined by the electrical characteristics of the

stuff it's traveling through. It turns out that the stuff with electrical characteristics

that produce the highest speed happens to be vacuum ... empty space with no stuff

in it at all. Those electrical characteristics produce a speed of 299,792,458 meters per

second. Introducing any kind of stuff into the space changes the electrical characteristics

to numbers that produce a lower speed. Maybe there's some kind of stuff that you could

spray into empty space that would have electrical characteristics that would produce a

higher speed, but none has ever been found.

Answer 4

Either -

The density of the medium through which it is passing.

or

The nature of space itself.

Answer 5

299,792,458 metres per second