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Speed of the light!

  1. Jul 20, 2010 #1
    hello scientists!
    Im new user. so I dont know manythings about physics.

    one more thing:I dont 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?
    Last edited: Jul 20, 2010
  2. jcsd
  3. Jul 20, 2010 #2

    Doc Al

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    Staff: Mentor

    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" [Broken]
    Last edited by a moderator: May 4, 2017
  4. Jul 20, 2010 #3
    thanks alot.
    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 cant be faster than light. so why the black holes can suction the light?

    thanks for your help!
  5. Jul 20, 2010 #4

    Doc Al

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    Staff: Mentor

    Yes. A disturbance in the gravitational field is believed to travel at the speed of 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.)
  6. Jul 20, 2010 #5
    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?
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