How can the speed of light be constant?

Question

I have read that the speed of light is constant, even if measured from objects moving at near-light speeds. How can this be?

TOP CONTRIBUTORS: Do not bother answering this question, I do not pick TCs as "best answer". I don't even want you getting 2 points for answering, but I have to live with that, I guess. Better yet, if you are a TC, MOVE ON TO THE NEXT QUESTION...because I WILL GIVE YOU NOTHING.

Answer 1

I know the answer to your question, but I WILL GIVE YOU NOTHING.

Answer 2

I agree with "aviophage".

What's up with that, dude? You're a top contributor because you answer a lot of questions, not because you don't know the answer.

Now, to answer your question, light is not a "normal" thing. It has mass, I believe, and it's made of photons. Light is a wave. Visible light is what we see. There are different frequencies of waves, such as sound, or radio waves, or micro waves, or cosmic waves, but light is what our eyes can detect. Light travels at almost 300,000 kilometers/second, and for some reason, it is always like that, no matter how you observe it.

Your question does not have a simple answer, nor one that could be answered simply. You have to do more research yourself, and perhaps not be so harsh next time.

Answer 3

I'm not sure there's a satisfactory answer to "how", but that's the way the universe is put together. The key fact is that you can't measure any motion relative to space, as first demonstrated by Michaelson and Morley about 120 years ago. No matter how fast you're traveling, the properties of space, including the speed of light, are the same in all directions.

Answer 4

The speed of light is NOT constant.
The number referred to as "C" is the speed of light in perfect space or also stated as a perfect Vacuum.
Anytime light travels through a medium of a different density, it slows down and in a very measurable amount in some cases.
This diffrence must be taken into account when engineering transmission lines for optical fiber networks etc.

Adolph

Answer 5

Um... I never cared much about the points - I just like answering questions.

It's a fundamental law in our universe. In another universe, the speed might be different. The speed at which photons move (and, photons *must* move) is the same, no matter the speed of the object that generated them, or reflected them.

Answer 6

speed of light is constant bcoz light travel wth the top speed of 3.14*10^28 or some thing like that in a? now the top speed that men are able to manage is not even the 1 or to percent of the speed of light so.here i 'd like to ask u a question if u get marks less than 35 or 40 percent than u tell me ur marks r considerable or not?

Answer 7

it's a constant, because we currently lack the technology to study light more closely, since light can be bent, which is a physical property so it might have some mass, but that too can not be proved other then a black hole.

anyways we just say it's a constant, since even if the speed did vary, it would not do so by much. the speed of light is a constant like 3.14 is pie, but really know its 3.1415.... to infinity.

Answer 8

The constant speed of light is one of the principals of physics that will always remain in our universe. It's speed is constant, because it is the speed of anything with zero rest mass. Because radiation has no mass, it would not have anything to slow it down physically.

Answer 9

It seems paradoxical, at first glance; but experiments show that it's true. Further reading about the relativity theory will enlighten you about this subject which could hardly be perectly explained with a few lines of text here.

Answer 10

We don't know. It is just a measured fact. Like the strength of gravity or whatever. It just is a fundamental constant of the universe and we just have to learn to understand it and live with it.

Answer 11

I think it is not constant because when you are given the speed of light it is the speed of light in a vacuum