Why does Light travel at the speed it does (speed of light)?

Question

Why not faster and why not slower? Why at a constant speed? Why so fast? What causes it to travel at the speed of light?

Answer 1

The speed of light is a "phenomenological parameter" of present theory. That means a free constant of the theory that can only determined by measuring it. Others include proton mass, electron charge, and such. Some future theory may change this but for now, that's just the way it is.

Answer 2

I can't help you with the part of your question 'why does light travel at the speed it does', because, frankly, I don't remember - but it was in Richard Feynman's book "Six not so easy pieces".

But I can remember the part about the constancy of the speed of light - it went something like this:
We all know that light follows the fastest path when traveling from point A to point B.
Well, it doesn't just travel straight 'through space', but also travels straight 'through space-time'.
So, if we graph the progress of a photon through space-time (let's have space parallel to the x axis and time parallel to the y axis) we find that the photon moves through space (horizontally) and also through time (vertically).
The path will have a slope that corresponds to it's speed and the graph will be straight, indicating the shortest path between the two space-time points.
If the speed varied the graph would not be straight and it would not be the shortest path.
The same wave mechanics that causes a light ray to follow a straight path through space also causes it to follow a straight path through space-time.

I just can't remember the rationale regarding why the slope is what it is.

Answer 3

No one knows. It's just one of fundamental constants of the universe. Every thing in the universe happens because of something else, or has the value it does because of something else -- except the fundamental constants.

Among these are: Planck's constant h, the gravitational constant G, the speed of light in the vacuum c, the electric constant ε0, and the elementary charge e. The Standard Model of particle physics has 25 arbitrary constants; there is no "reason" why these have the values that they do -- it's just the way things are.

Answer 4

You suggestions became incorrect approximately all means having mass. Radiation, or easy waves incorporate no mass. some human beings argue that it has an 'valuable mass' given by using the extremely some E=hf (engery=plank's consistent circumstances the frequency), yet that remains debated. Reguardless, easy has no mass, and that's the reason it may shuttle @ the cost of light c. you're suitable approximately accelerating a partlice in the direction of the cost of light could require countless quantity of means. in case you're extremely intrested look @ Lorentz variations, and you will see the extremely common why something with mass can no longer attain the cost of light.

Answer 5

The energy level of a photon is arrived at the instant it is ejected, there is no acceleration time and it designated as c because of Einsteins selection of that letter representing constant, the speed of light is the only constant in the universe.

Answer 6

Light travels at a speed that was measured relative to the same frame of reference as the Earth.
At a different frames of reference in the Universe it would travel at different speeds.
The speed that light travels is a function of the pressure density of space.
The larger a mass is the slower it moves.
Light being the smallest mass structure of the Universe that is constant. would be the fastest moving micromass of the Universe.

Answer 7

Visible light is a set of frequencies of electromagnetic radiation that can be detected by the human eye. These frequencies, and all other frequencies of electromagnetic radiation (from gamma rays to microwaves) travel through space as mutually perpendicular electric and magnetic fields. Without going into unnecessary detail, a changing magnetic field induces an electric field, and a changing electric field induces a magnetic field. So, as the magnetic field of an electromagnetic wave travels through space, it causes the propagation of an electric field perpendicular to itself, which then causes the propagation of a magnetic field perpendicular to itself, and the process goes on, like a leap-frog game between perpendicular electric and magnetic fields. These magnetic and electric fields follow sinusoidal patterns (waves).

The rate at which these fields are able to propagate in empty space (or any other medium) is known as the electric permittivity of space (for electric fields, designated as ε) and the permeability of space (for magnetic fields, designated as μ). The values of each vary between mediums, with permittivity in a vacuum being roughly 8.85 X 10^(-12) farads/meter, and the permeability in a vacuum being roughly 4π X 10^(-7) henries/meter.

There are a set of equations, derived by James Clerk Maxwell, that describe the behavior of electric and magnetic fields. Once again, without going into a lot of annoyingly complex mathematical detail, the velocity of electromagnetic waves, as given by Maxwells equations is:

v = [ε*μ]^(-1/2), which, in the case of a vacuum, happens to be c, or 3 X 10^8 meters/second. In other mediums (such as air, or water) with particles for the electromagnetic waves to bounce into, etc, the speed decreases, although in the case of air, this decrease is so small that for most purposes, it's negligible.

So, in summary, to answer your question, the speed of light (and other electromagnetic radiation) seems to be determined by the intrinsic properties of the universe. Why at a constant speed? Because if traveling through empty space, there's nothing for the waves to run into (or nearly nothing), so what would cause them to change their speed? Why so fast? Well, that's a philosophical question - another valid question would be "why do WE travel so slow?"

Hope this helps. If you're interested in Maxwell's equations, do a search on Wikipedia or check out a physics textbook.

Answer 8

acording to Albert Einstain you cant travel faster then the speed of light, as you get closer your mass will get biger so you will nedd more energy to accelerate. at 99% of speed of light your mass will be so big that you almost wont be able to accelerate.

Answer 9

Anything massless travels at c, not just light. But why is c c? *shrug* I don't know. Ask the philosophers.