How can the can the speed of light be constant in every frame?

Question

what does this mean? please give me examples what is not constant?

Answer 1

Hi. Any tool you use to measure the frame is affected by speed in that frame. As you increase the speed you shorten the tool.

Answer 2

Simply because it is. One can measure it and that's that.

Another thing that stayed constant over the hundred and twenty years since the relevant experiments were done is this:

People start with the wrong assumption that non-relativistic physics is valid and then ask how the speed of light can be constant since it contradicts non-relativistic physics.

But it is really the other way round: the speed of light was always constant in any rest frame since the beginning of the universe and non-relativistic physics was always wrong. And it simply continues to stay wrong. And the speed of light continues to stay constant. The only way to resolve "the paradox" is to actually learn the correct theory and discard the wrong one.

The ONLY reason why we continue to teach non-relativistic physics first is because it simplifies the naive understanding of students of measurements and rest frames. It would be almost impossible to teach special relativity first without losing all but the smartest and most insightful students. This way we only lose 90-95%.

:-)

And as to the last part of your question: since the speed of light is constant, the things that can not stay constant are spacial and temporal scales. Instead they become observer dependent.

:-)

Answer 3

All wrong so far.

The answer is because there is no absolute time.

We tend to think that there is because we never move very fast and so we all agree on time. If we moved faster we would not - we would all keep different time. This phenomenon is also sometimes referred to as the failure of simultaneity - we assume all event simultaneous for us are simlutaneous for everyone, but this is simply not true. In fact, events are only simultaneous for all observers if they occur at the same position in space.

And of course there is also no absolute space.

For more see Roger Penrose book The Road to Reality.

Answer 4

It is not. Light slows down every time it passes through anything..the atmosphere, a lens, etc. The amount of slowing is so little as to be not worth talking about, in most cases, so you may as well say the speed is constant...even though it technically is not. In fact, matter is just extremely slowed down light.

Answer 5

Easy, Lf = c; where c = light speed, which is constant for a given medium, like air. L is wavelegth and f is frequency. These are the things that vary, but they vary so that c remains fixed. Lf = c applies to all electro-magnetic energy (i.e., photons).

Thus, when we tune in a radio frequency f, its wavelength must be L = c/f. Sometimes you hear ham radio operators talk about 3 meter bands and such. They are talking about the wavelenght they are operating in, but because of f = c/L, they are also talking about the frequency they use.

Answer 6

when light get bounced of a spot, it duplicates and becomes.ooooo1 ms faster. therefore in no time it covers every frame