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Category: Science
Date: 02/10/14 09:57 AM

12 Responses to Three Possible Ways The Universe Will Be Destroyed

  1. Profile photo of DuckBoy87
    DuckBoy87 Male 18-29
    3288 posts
    February 10, 2014 at 9:47 am
    Link: Three Possible Ways The Universe Will Be Destroyed - Will it be the big freeze/heat death, the big rip, or the big crunch?
  2. Profile photo of patchgrabber
    patchgrabber Male 30-39
    5812 posts
    February 10, 2014 at 10:54 am
    Most evidence suggest that a big crunch isn`t very likely, the acceleration of expansion doesn`t really support it.

    It`s also important to note that it`s not just dark energy affecting expansion, it`s gravity too, as at very large distances and certain densities, gravity is repulsive rather than attractive.

    Dark energy is thought to be a constant negative pressure in all space. What is important about it is that its density is constant. This means when we double the volume of our box and keep the density constant we get double the amount (of negative pressure).

    So we have various forms of energy and all of their densities respond differently when we expand our universe, some of these change the integrated energy. This isn`t a problem because we know that energy is only conserved when a system doesn`t change in time so we don`t need to be surprised when our law doesn`t hold for an evolving universe.
  3. Profile photo of Gerry1of1
    Gerry1of1 Male 50-59
    36860 posts
    February 10, 2014 at 11:02 am

    I like the Big Bounce theory. The whole circle of life thing on a BIG SCALE.

  4. Profile photo of FredSpudman
    FredSpudman Male 18-29
    653 posts
    February 10, 2014 at 2:07 pm
    @patchgrabber "... as at very large distances and certain densities, gravity is repulsive rather than attractive." Elaborate on this point. Assume your audience has but a vague grasp of science.
  5. Profile photo of uatme
    uatme Male 18-29
    1074 posts
    February 10, 2014 at 3:02 pm
    The first too sound the same
  6. Profile photo of uatme
    uatme Male 18-29
    1074 posts
    February 10, 2014 at 3:03 pm
    Obviously I meant the first 2
  7. Profile photo of razbitom
    razbitom Male 40-49
    913 posts
    February 10, 2014 at 6:59 pm
    a much more compendious list of likely (and unlikely) scenarios is available on EXIT MUNDI.
  8. Profile photo of Draculya
    Draculya Male 40-49
    14654 posts
    February 10, 2014 at 7:49 pm
    Who cares?
  9. Profile photo of Thonious
    Thonious Male 40-49
    987 posts
    February 11, 2014 at 4:40 am
    A more appropriate title might have been, "Three currently-debated models disregarding several others that do not have the same degree of acceptance in popular literature."

    Too many assumptions and not enough evidence to justify thinking of this as a scientific subject. It is a matter of philosophical discussion. When physicists delve into philosophical debate they should remember to take off their physicist hats and put on their philosopher hats (so people will not get confused) and use the tools of philosophers in their discussion. It`s okay for physicists to be philosophers also, but to offer yourself as one without the necessary set of skills and tools is like a butcher pretending to be doctor without the training.
  10. Profile photo of patchgrabber
    patchgrabber Male 30-39
    5812 posts
    February 11, 2014 at 4:43 am
    @Fred: Ok I`ll try. Newtonian gravity, F = GmM/r2 as taught in high school, is always attractive.

    Newtonian gravity is approximately correct, but breaks down for extremely large scale systems such as the observable universe, and very dense systems such as neutron stars. If you observe the orbit of Mercury with incredible precision, over a few centuries the position of Mercury will shift very slightly in comparison with what Newtonian gravity predicts. One can account for this discrepancy, and understand systems such as neutron stars and the large scale universe with Einstein`s General Relativity. You would need a good understanding of General Relativity and its equations to see how it predicts expanding universe, gravity, etc.

    But to answer your question, gravity is not just one force but a combination of forces. Within the solar system the attractive force is stronger, but in deep space matter isn`t dense enough to overcome the repulsive force.
  11. Profile photo of patchgrabber
    patchgrabber Male 30-39
    5812 posts
    February 11, 2014 at 4:45 am
    ...This is a bit of an oversimplification, and it also has to do with dark energy, since the density of dark energy never changes, but the density of matter does, and the forces influenced by each.
  12. Profile photo of normalfreak2
    normalfreak2 Male 18-29
    4084 posts
    February 11, 2014 at 5:50 am
    It`s nice to throw around theories about this but let`s be honest we haven`t the faintest clue. And making ascertations right now about what will happen quadrillions of years in the future at "THIS" time is pretty pointless. When we finally figure out how to harnass the power of a star we should probably look into this. (Hopefully if it doesn`t take us trillions of years.)=p

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