Space can expand faster than the Speed of Light?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Saint, Sep 1, 2011.

  1. Saint Valued Senior Member

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    Space can expand faster than the Speed of Light?
    Therefore, the galaxies faraway appear to be moving away from us faster than the speed of light.

    I read this in internet, and youtube too.

    Can anyone clarify?
     
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  3. phlogistician Banned Banned

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    Try reading a physics book instead.
     
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  5. origin Heading towards oblivion Valued Senior Member

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    Correct, the expansion of space can result in 2 galaxies very far apart to have recession velocities that are greater than the speed of light. It is important to note that the galaxies are NOT traveling through space faster than light (which would violate SR), instead the space between them is expanding faster than light.

    I am confident [not] that this subtlety will not be lost on you.

    Please Register or Log in to view the hidden image!

     
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  7. Saint Valued Senior Member

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    Yes, I read about this theory too,
    anyway, the relative velocity between galaxies would be > c, right?

    In this case, Young Earth theory could be true,
    God created the universe in the beginning, and accelerated galaxies to fly off with the expansion rate which is very fast, the earth is only ~6000 years old.

    Genesis is true, thanks God.
     
  8. Rhaedas Valued Senior Member

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    1,516
    What a waste of material and space that would be.
     
  9. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    Um, no.

    Really? What evidence do you have?
     
  10. Crunchy Cat F-in' *meow* baby!!! Valued Senior Member

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    Correct.
     
  11. Crunchy Cat F-in' *meow* baby!!! Valued Senior Member

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    Incorrect, points of space are added so fast between the galaxies that the distance between them is increasing > c. The actual velocity of the galaxies relative to any single point of space are immensly slower.

    Incorrect. Your idea is based on an incorrect understanding space expansion, an incorrect understanding of aging, and the existence of a non-existent entity.
     
  12. origin Heading towards oblivion Valued Senior Member

    Messages:
    11,890
    So your logic is:

    A = B
    and
    B = C

    Therefor

    X > Tuesday

    Praise God!:bugeye:
     
  13. Saint Valued Senior Member

    Messages:
    4,752
    Let us have a static co-ordinate system in space, the velocities of galaxies are measured with reference to this coordinate, what would be their speeds?

    What caused the space to be added so fast, faster than c ?
     
  14. NietzscheHimself Banned Banned

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    867
    I have a double sided laser pointer. I turn it on. How fast is photon A moving away from photon B?
     
  15. James R Just this guy, you know? Staff Member

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    No. The expansion rate of the universe is nowhere near fast enough for it to be only 6000 years old.
     
  16. Crunchy Cat F-in' *meow* baby!!! Valued Senior Member

    Messages:
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    It depends on the galaxy, they don't all move at the same speed you know.

    Nobody knows why the universe is presently expanding. The limitation of C that you are thinking of only applies to objects with mass.
     
  17. James R Just this guy, you know? Staff Member

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    39,426
    Their speeds would be given by the Hubble law.

    It is thought to be due to the residual "push" from the big bang, combined with the accelerating effect of dark energy. At least, that's the best guess at this point.
     
  18. Saint Valued Senior Member

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    4,752
    When you say the galaxies won't move faster than light while the space does move faster than light, this is a dilemma.
    Let's imagine the space is a bullet train moving with the speed of 360 km/hr, I am on this train walking with a slow speed of 5 km/hr relative to the train, at outsider who is static look at me, he will see me moving at 365 km/hr, right?
    So, back to the galaxies, the space expands so fast and "pushes" the galaxies away from us at the speed faster than the speed of light, when it is measured from our static coordinate here, it is nothing wrong to say the galaxies are moving > c.

    or, we may think that the space is the speed of the current of the sea, a boat which sails with a lower speed of 20 km/hr relative to the surface of the sea, but the current has a speed of 30km/hr, when a person who is standing on the shore measures the speed of the boat, he will measure it is 50km/hr.


     
  19. phlogistician Banned Banned

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    10,342
    RELATIVITY.

    DUDE, really, in space, how do you anchor your reference point? If you leave a marker in space, and fly off in your rocket ship, how do you know it isn't moving too? All you can do is calculate the relative speed between objects, there are no absolute co-ordinates in space.
     
  20. phlogistician Banned Banned

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    10,342
    Photon A is moving away from the Laser pointer at c. Photon B is moving away from the Laser Pointer at c. Photon A is moving away from Photon B at c also. This is the headfuck that is relativity.
     
  21. Saint Valued Senior Member

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    4,752
    Why not 2c ?
     
  22. Crunchy Cat F-in' *meow* baby!!! Valued Senior Member

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    8,423
    I suspect the dilemma is only in your understanding, but go on...

    There is nothing wrong except the entire statement. All you can state is that galaxies are being seperated faster than C. You cannot declare that speed as being the actual velocities of the galaxies. Here is why. Space is the container for the galaxy's involved and galaxy velocity occurs within their areas of the contianer. If more volume is added to the container elsewhere then it doesn't change the galaxy's velocities at their present locations.


    You can think of space that way but it would be incorrect. You are treating space as if it were matter and it simply is not. Stand still, declare a 15x15x15 cube of space around you as your "personal space". Now, instantly add 100 lightyears of new space around your personal cube. Guess what? You have not moved an inch.
     
  23. Fraggle Rocker Staff Member

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    What exactly is a point of space? Until today I thought that points, lines, circles, etc., were simply abstractions we invented for our own convenience so we'd have words to use in discussing and describing the universe.

    Are you now saying that a point, which by definition has zero size, zero mass, zero inertia, zero charge, zero spin, etc., is a real thing? Without mass, inertia, charge, etc., how can we detect and observe points in order to verify their existence, much less their behavior?

    I recall that the first section in my Physics 101A textbook was titled, "Linear Kinematics of a Point-Mass." But it was made clear in the preface that there is no such thing as a point-mass. It was a fictional artifact used to make the lessons simpler and easier.
     

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