Since there is a speed of light, what is it's acceleration?

Answer 1

In quantum mechanics things are grainy and even a bit fuzzy. The energy level of an electron changes and a photon zips off at the speed of light. So you may assume that the photon was just resting on the electron or maybe was created and had to accelerate. Physics is concerned with measurement. According to quantum mechanics, backed up by experimentation, there is no acceleration of photons. Physics is not about what you believed happened, but only what actually did happen in the way of measurement. Now string theory was invented in order to explain things, even though it has never been proven that a string actually exists. So sometimes physicists do talk about things they have not seen or measured but only if it has the purpose of explaining something that has been measured. So we have a bit of a quandary. I can only say that it has not proven theoretically useful to consider a photon as accelerating, so considering it as such is not accepted by the physics community. It goes against quantum mechanical ideas and is not part of any theory of elementary particles, and so far, has no theoretical usefulness.

Answer 2

OK, just to be different, I'll go against the crowd here and say light can be accelerated.

The speed of light is constant, however speed is a scalar quantity. It is the magnitude of velocity. Velocity is a vector quantity. It does have a magnitude and a direction. Likewise, acceleration is also a vector quantity. It also has a magnitude and direction.

An object whose speed is constant, but is changing direction is accelerating. An example of this is uniform circular motion. Since light can be bent around a massive object (gravitational lens), it's direction is changing, thus it is accelerating.

It's acceleration cannot change it's speed, only direction. This is because a photon has no mass, and anything without mass cannot be accelerated to a higher speed.

Answer 3

The reason the question isn't answerable is because light acts as a particle and a wave.

The true acceleration of light happens on a subatomic level: light is generated when an electron jumps from a higher electron teir to a lower one, giving off light. The opposite and equal reaction to this is expelling light.

Because it also acts as a wave, the speed of light has been known to change around high-gravity areas, but once it passes those gravitational fields it returns to the more conventional speed of light. Stuff out in space is so relative...

Answer 4

If you are asking how long it takes light to get to light speed, that's a pretty good question, actually. But light achieves light speed at the instant that the photons are created. There is no acceleration, just instantaneous full speed.

Answer 5

The speed of light is constant. Acceleration = zilch.

Answer 6

The speed of light in vacuum is constant. Therefore, no acceleration.

Answer 7

Light always moves at speed of light, in any frame of reference. It does not accelerate nor brake.

Answer 8

light is an electromagnetic wave
this means tht it doesnt need a material medium to pass through
n even when it is in the air
it doesnt interact with particles
therefore there is no change in velocity
thus it goes with constant speed

THerefore no acceleration

Answer 9

accelaration is defiened as rate of change of velocity. but light in any particular medium travels with a constant speed thus there is no accelaration. but wen it refracts speed changes and then there is an accelaration or decelaration.

Answer 10

0 since its velocity is constant