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Thread: Universe expands faster than light

  1. #1 Universe expands faster than light 
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    I recently saw this history channel's "the Universe" episode, were it was stated that nothing moves faster than light, and that the universe expands, so that everything is separating from everything else (the ballon with the dots example).

    OK till then, but then they said that closer objects to us are moving away from us slowly, and distant objects are moving away from us faster.

    Then they talked about that there is a "see limit", were our telescopes cannot see through it, and they said it was because the space between us (Earth) and the stuff behind that limit is expanding faster than the speed of light. Which actually makes sense, so that would be why we can't see it, 'cause light doesn't reach us. They also said that another civilization behind that limit could also not see the Earth, because it would be over their "see limit".


    now the question:
    Anyone know why the distant objects expand at a faster rate than the closer ones?
    Is it because the "space expand rate" doubles everytime we double the space from an object to another?


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    Exactly. The objects themselves do not move, it is the spacetime that expands and drags everything with it. You already mentioned the analogy with the expanding balloon. If you put yourself on one spot, you do not notice it moving. But for you, everything else recedes with a higher speed the farther away it is from you. Everybody else on the other spots would see the same.


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    But why is it that the further an object is from the observer, the faster it moves away from you?
    Thus the nearer an object, the slower it moves away....

    I don't get that part, though my guess is maybe right (tell me if it is, lol):

    If we increase the space between to objects, the "space expansure rate" also increases.
    I thought that maybe it is the space expansure rate between stars that adds up.
    I imagined that for example, from the milky to Andromeda (nearest galaxy), the space expansure rate is slow, because there are only a couple million stars (small amount) to Andromeda, so the expansure rate of the stars towards us (milky way) adds up: Expansure rate from star 1 to milky way + expansure rate of star 2 to milky way, etc.
    The furthest a star is, the more expansure rate it has towards us, 'cause it adds the other expansure rates of the previous stars (the ones nearer to us).
    So the stars are like poles to mark the distances in this model.

    Another very far away galaxy moves much faster away from us, because there are more stars from us to that galaxy, thus more to add, and thus more expansure rate.
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    I think you are getting it right. Just a simple example: Imagine three points in space separated by the same distance. Expansion increases all distances by a certain rate. Now, what do we get?

    The point in the middle measures again identical distances to its neighbouring points. So, they receded by the same rate, i.e. with the same velocity.

    Seen from one of the other two points, we measure different increases in distance to the other two, because they add up. The increase to the distant point is twice as high as the one to the neighbouring point. This means, we measure different rates, i.e. different velocities.

    So, the bottom line is that all distances increase by the same rate. And the farther you look, the more those individual increases add up. At some point this velocity reaches the speed of light, which defines the viewing distance.
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    thanks, you made it clear now.

    So when in the history channel they said that there is a point where space expands faster than the speed of light (we cannot se further than that point with our telescopes), they ment it for us as the observers. The space there expands as fast as any other, but the distances add up.

    Thanks for the help mate
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  7. #6  
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    The elephant in the room. How does space expand?
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    Quote Originally Posted by Cyberia
    The elephant in the room. How does space expand?
    Outwards. All distances increase.

    Please do not hijack threads to bring forward your hypotheses. We have discussed your views in other threads already many times. Don't you think that is enough?

    Dishmaster
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  9. #8  
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    The BBT is NOT expanding at the velocity of light.
    It is expanding at the calculated rate of 72 kms/sec/mpc.

    But the expansion between the objects is expanding at an ADDED rate according to the distance between the objects.

    In other words, objects at a separate distance of 2 x 72 kms are expanding at that rate that is twice the Hubble Constant.

    So in this way, the expansion between objects is increasing at an added rate of
    d x HC that increases with time.

    So the further an object is from us, the faster it is receding.

    Cosmo
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  10. #9  
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    Quote Originally Posted by Dishmaster
    Quote Originally Posted by Cyberia
    The elephant in the room. How does space expand?
    Outwards. All distances increase.

    What are the mechanics of expansion that it can make space take up an ever larger area?

    Don't straight jacket arguments by saying what can and cannot be discussed. Debates evolve along many different lines.
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  11. #10  
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    Quote Originally Posted by Cyberia
    Quote Originally Posted by Dishmaster
    Quote Originally Posted by Cyberia
    The elephant in the room. How does space expand?
    Outwards. All distances increase.

    What are the mechanics of expansion that it can make space take up an ever larger area?
    This is unknown, as you know yourself. But that does not mean that the theory is wrong. At some point, the force that keeps the earth in an orbit around the sun was also unknown. But the new heliocentric model of the solar system was still correct.

    This is still a matter of current research. Do you want to request all science to be stopped just because scientists are still looking for the fundamentals in these topics?
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  12. #11  
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    Quote Originally Posted by Cyberia
    Quote Originally Posted by Dishmaster
    Quote Originally Posted by Cyberia
    The elephant in the room. How does space expand?
    Outwards. All distances increase.

    What are the mechanics of expansion that it can make space take up an ever larger area?

    Don't straight jacket arguments by saying what can and cannot be discussed. Debates evolve along many different lines.
    I can think of a mechanism that allows space to become larger. The Lorentz Contraction occurs when an object is moving through space at high velocity relative to what we will call a stationary point. This causes space to appear smaller along the route of travel from the objects point of view.

    When the object begins to decelerate, the space expands to normal again. So, there you have expanding space.
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  13. #12  
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    Good post, a thinker, proves that these so called boundaries arne't true.
    the more science you know, the less crap you get.
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  14. #13  
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    bad post, JoshuaCarter, it proves nothing of the kind - you have a faulty definition of the concept "proof"
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
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