What is the speed of light and how is it measured?

[BDfarsi]

hello scientists!
Im new user. so I don't know manythings about physics.

one more thing:I don't know english well.

I just have a question about "Speed of light".
Whats the real speed of it?
300,000 k/h Or 300,000,000.001 m/h?

whats the rule of it?

The light's speed is the same as the gravity's speed?

What are your answers?

 

[Doc Al]

I just have a question about "Speed of light".
Whats the real speed of it?
300,000 k/h Or 300,000,000.001 k/h?

The speed of light is 299,792,458 m/s. (≈ 300,000 km per second, not per hour.)

See: http://en.wikipedia.org/wiki/Speed_of_light"

 

[BDfarsi]

thanks a lot.
I think its very important in our equation and i didnt know it!it was too bad!

another question:
The light's speed is the same as the gravity's speed?

I think gravity has a real speed and It can't be faster than light. so why the black holes can suction the light?

thanks for your help!

 

[Doc Al]

another question:
The light's speed is the same as the gravity's speed?

Yes. A disturbance in the gravitational field is believed to travel at the speed of light.

I think gravity has a real speed and It can't be faster than light. so why the black holes can suction the light?

Spacetime around a black hole is so distorted it curves back onto itself. (I'm sure there are folks here who will give you a much more detailed answer, if you need one.)

 

[BDfarsi]

Its so good!

So I can not interpret.
I think even the distance (eg time) in a black hole is not defined and strange.
Let alone the speed!

A very small object, which is related to quantum mechanics and high crime s that gets laws of relativity. These two are not compatible! Is there a link between them?