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Is the universe going to die?

  1. Mar 14, 2012 #1
    If the following deductions are correct:
    Why the Universe Can Never Die!

    (Using the accepted hypothesis of today’s science as basis)
    1. Everything was created at the time of the Big Bang. Matter was disintegrated and expanded as exploding atomic particles
    2. This Matter was accelerated outward
    3. Different Elements began to form as nuclei, electrons and protons began to coalesce
    4. Gases, dust were attracted by gravity and formed into Nebulae
    5. Nebulae coalesced into Galaxies
    6. Galaxies gave birth to Stars and solar systems
    7 Stars ignited due to compression of gravity and ignited the Hydrogen at core into fusion reactor
    8. Stars exhausted their fuel of Hydrogen, Helium, Oxygen and lighter elements turning the matter into heavy metals
    9. Star begins to grow into a giant Nova , swells engulfing nearer planets
    10. Star collapses into Nova and explodes leaving a Black hole
    11. Black hole begins to devour entire solar system
    12. Lesser systems migrated to black holes devouring those systems, black holes and other matter/energy
    13. Central galactic black hole’s gravity coalesces entire galactic system
    14. Black holes combine in galactic center compressing captured matter further.
    15. Galaxies begin to attract each other, coalesce and are swallowed in universe central singularity black hole
    16. Matter and energy exceeds the hole’s gravity ability to contain
    17. The Singularity Black Hole absorbs itself and re-explodes creating another big bang, disintegrating all captured elements into basic atomic particles.

    Compiled by
    Jack Lewis
  2. jcsd
  3. Mar 14, 2012 #2

    Points 1 through 10 are approximately correct, 11 through 17 are simply wrong.
  4. Mar 14, 2012 #3
    Point 2 is wrong, the big bang wasn't an explosion in space as the poster seems to think.

    11 to 14 are roughly right, and in the heat death scenario, the first half of 15 could apply to clusters but of course the second half is wrong, there is no centre. Item 16 is the biggest error though, there is no upper limit to a black hole's mass.
  5. Mar 14, 2012 #4
    In 11 it says that the black hole will devour its solar system. A black hole with a similar mass to the original star would have the same effect on its orbiting bodies as the star would have had. There's no mechanism for the orbiting bodies to be "devoured".
  6. Mar 14, 2012 #5
    1-2 The big bang has been described as a singularity exploding from at that time, the center of the universe.
    15 It has been photographed, the galaxies colliding and combining.
    In the parameters known or theorized today the center of galaxies are black holes.
    Black holes consist of inescapable gravity.
    Given time the strongest influencial galaxy will absorb the balance of a collapsing universe.
    Granted, Item 16 should have been labeled a supposition.
  7. Mar 14, 2012 #6


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    Also realize that current observations show the universe will continue to expand forever, rendering anything other than galaxy clusters and their associated galaxies unable to be stay bound to each other, so no black holes would coalesce to form one giant universal one.
  8. Mar 14, 2012 #7
    There is also the theory that eventually the universe will cease to expand and collapse. It probably won't happen before I get my apocalypse shelter finished.
  9. Mar 14, 2012 #8


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    Simply because some people describe it as such does not make it so. It is incorrect to think of the BB as an event taking place in a fixed background or anything like that (this goes along with the fact that there is no center of the universe, a topic covered many times on this forum). Indeed, it is speculative at all to describe things that happened before roughly the planck time. All we can say with (scientific) certainty, is that the universe was much smaller and denser in the past.

    True, some galaxies do collide and combine. However, these are only galaxies which are relatively close together -- ones which are farther away will never collide. And yes, current understanding indicates most (if not all) galaxies have supermassive black holes at their centers.

    This is false. Far away, the gravity of a black hole is no different from that of any other object. That is to say, if the Sun were to, through some magical process, collapse into a black hole, the Earth's orbit would be unaffected. So while it's true that isolated massive stars will form black holes, they will in no way 'devour everything in the universe'.

    With re. to your item 16, there is no such limit on the mass of a black hole. It's not like they are buckets of some finite size, beyond which things start to fill out. Rather, they are regions in spacetime that are causally disconnected from the outside universe due to extreme gravitational curvature.

    Once these points are understood, I think it becomes more obvious why your final point is nonsense.

    Re: A cyclical universe theory, it is theoretically possible for a universe to expand and re-collapse, creating a so-called 'big crunch'. However, observationally it appears as if we do not live in such a universe, as ours will continue expanding forever.
  10. Mar 15, 2012 #9
    The mechanism is gravitational radiation, see Hulse and Taylor's observations of PSR_B1913+B16 for which they won the Nobel Prize:

  11. Mar 15, 2012 #10
    Unfortunately, many descriptions are poorly written. It is a singularity in the same sense that the equation y=1/x has a singularity at x=0 but it isn't a centre, the singularity occurs everywhere. The portion of the universe we can see has a centre of course, it's us, but an alien civilisation living 40 billion light years away could say the same.

    True, and on this map you can see our galaxy as well as Andromeda, we will collide in about 3 billion years:


    In fact all of the galaxies on that map might end up coalescing. However, zoom out one level to the larger structure:


    On that map, the Eridanus and Formax Clusters might each merge and possibly merge with each other but they will never join with the Virgo Cluster, those two groupings are too far apart. They are separating at an ever increasing rate.

    Zoom out one more and the pattern of fluff you see is typical of the whole universe, and those patches are certainly never going to join up.

    No, it's just plain wrong. Black holes cannot explode but they are thought evaporate through Hawking radiation which is thermal. In other words all the mass gets converted into heat and light which then gets redshifted to nothing ... The End.
  12. Mar 15, 2012 #11
    The quoted study is of a Pulsar, not a Black Hole
  13. Mar 15, 2012 #12
    The study shows a binary system whose orbits are decaying because energy is being radiated away (probably) in the form of gravitational waves. That applies to any orbiting configuration, though the energy loss by the Earth orbiting the Sun for example is at a much lower rate. Given enough time, all the stars in our galaxy will either merge with Sag A* or by ejected from the galaxy if random encounters push their speed above escape velocity (i.e. as in "evaporation" from a globular cluster due to the statistical nature of the virial theorem).
  14. Mar 15, 2012 #13


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    This is what the science says:
  15. Mar 15, 2012 #14


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    While this is true, the timescale for inspiral of planetary bodies orbiting ~solar mass black holes is ridiculously long. Planets will likely be ejected through normal Newtonian gravitational and tidal interactions long before the gravitational radiation has a chance to shrink their orbits down to zero. For example, the lifetime of the Earth's orbit owing only to gravitational radiation is 10^23 years.
  16. Mar 15, 2012 #15
    i like it jack.

    Is there current evidence that black holes evaporate? I was too lazy too click on the Hawking radiation wiki link.
  17. Mar 15, 2012 #16


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    You expect someone to take the effort to answer your post when you don't make the effort to read the available information? Cmon...
  18. Mar 15, 2012 #17
    thanks for taking the effort to respond to my post. i will now make the effort to read it. "yes" or "no" would have saved you some energy, but i get your point.
  19. Mar 15, 2012 #18
    As I said, some will be ejected from the galaxy but those that aren't will eventually become part of Sag A*. Item 13 on the list is valid, nobody said it would be quick.

    Stars that are ejected from the galaxy will quantum tunnel to iron stars in perhaps 10^1500 years and to black holes in 10^(10^26) years or more after which Hawking Radiation is again their fate so 10^23 years is the proverbial blink of an eye.


  20. Mar 15, 2012 #19


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    Unless Hawking radiation is real, in which even supermassive black holes will decay in about 2x10^99 years.

    Also, per wiki: Since encounters are more frequent in the denser galaxy, the process then accelerates. The end result is that most objects are ejected from the galaxy, leaving a small fraction (perhaps 1% to 10%) which fall into the central supermassive black hole.

    So no, number 13 is not accurate, as much of the galaxy will be thrown out, not sucked into the black hole.
  21. Mar 16, 2012 #20


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    Hawking radiation is real. It is a feature that any horizon must have, and has been observed for those horizons which we can create in laboratories (sound horizons).
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