The void: Imprint of another universe?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Michael, Nov 26, 2007.

  1. Michael 歌舞伎 Valued Senior Member

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    The void: Imprint of another universe?

    IN AUGUST, radio astronomers announced that they had found an enormous hole in the universe. Nearly a billion light years across, the void lies in the constellation Eridanus and has far fewer stars, gas and galaxies than usual. It is bigger than anyone imagined possible and is beyond the present understanding of cosmology. What could cause such a gaping hole? One team of physicists has a breathtaking explanation: "It is the unmistakable imprint of another universe beyond the edge of our own," says Laura Mersini-Houghton of the University of North Carolina at Chapel Hill.

    It is a staggering claim. If Mersini-Houghton's team is right, the giant void is the first experimental evidence for another universe. It would also vindicate string theory, our most promising understanding of how the universe works at its most fundamental level. And it would do away with the anthropic arguments that have plagued string theorists in ...



    Pretty cool huh?
     
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  3. draqon Banned Banned

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    "enormous hole" is what exactly? and if black hole is lack of light symmetrically casting itself as round sphere against cosmic background...than what is this "enormous hole"?
     
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  5. Michael 歌舞伎 Valued Senior Member

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    just a place were there are a lot less stuff compared with the rest of space. I'm curious if their prediction is true - thatthe same thing exists in the "southern" portion of our universe. Also, as this fits so nicely with string theory - well, all and all, I think its a step forward.
     
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  7. Reiku Banned Banned

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    Let me just digest this further. I don't support the parallel universe theory, in the long run, but i am always interested in this particular subject....
     
  8. Reiku Banned Banned

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    Ah yes... Dr. Wolf believes that they have made a mistake, as he says, ''I know how hard it is to catch those little photons.''

    I would take this gigantic hole with a pinch of salt.
     
  9. blobrana Registered Senior Member

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    As reported, it is a meaningless claim.
    The hole is unusual in that is larger than the `normal` voids - which may lead onto a revising of how such large voids could be formed.
    The current models are about a magnitude out. But, until other holes are identified it would be safe to say it could have formed just by pure chance.

    If more holes are found then it implies that there was something forming larger defects that got inflated, this would imply even large collections of mass, or larger structures than what we have already found.

    Position (b = 57°, l = 209°)
     
  10. kaneda Actual Cynic Registered Senior Member

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    If we have walls of galaxies where there is more stuff than usual, why not large voids too? Probably evidence that the BB is wrong and the universe may be a few times older than we think it is.
     
  11. blobrana Registered Senior Member

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    Hum,
    it is a bit like my bubble bath - if i suddenly find bubbles 10 time larger than normal then i need to revise my theories of how the bubbles are formed or the strength of the bubble bath solution. I don't need to increase the size of my bath or pull the plug and have a shower.
     
  12. shalayka Cows are special too. Registered Senior Member

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    It is notable that a solution consisting only of quarks and the strong nuclear force is much different than a solution consisting of atoms, planets, stars, galaxies, etc. The mechanics at all scales are defined by different solutions, no? The term "solution" is represented here both physically and mathematically.

    However, there must be some common (unified) solution somewhere. How to bridge the gap between \(\Lambda\)CDM cosmology / general relativity and the standard model of particle interaction. That's the goal. Oh, and can't forget about flat galactic rotation curves!

    Wouldn't that be cool if it did all turn out to be a big bubble bath though? With the greatest of respect intended, perhaps you should name it Rubber Ducky Theory? :thumbsup:
     
    Last edited: Nov 27, 2007
  13. Michael 歌舞伎 Valued Senior Member

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    What's "flat galactic rotation curves"?
     
  14. shalayka Cows are special too. Registered Senior Member

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    A trove of information is at:
    http://www.google.com/search?hl=en&q=flat galactic rotation curves&btnG=Search&meta=

    One of the first links will be Wikipedia's "Galaxy rotation curve". The diagram near the top of this page shows how the orbit velocity of material within the galactic disc is greater than expected when calculated by Newtonian gravitation. It's like something beyond "normal" gravitation is drawing the material outward, and everything orbits faster in order to maintain a constant distance from the centre of mass.

    The orbit velocity of the galactic disc's material is obtained by measuring the effects of relativistic Doppler shift (Special Relativity). Considering that the density of material is relatively low, and orbit velocity is low, the tiny deviation from Newtonian gravitation (manifested by General Relativity) may be ignored.

    The galactic rotation curve is called flat because it does not drop off like the curve for our own Solar System does (inverse-square law).

    Dark matter is commonly used to pose as the source of this extra outward pull. In a cold dark matter framework like \(\Lambda\)CDM, dark matter does not interact using electromagnetism.

    http://en.wikipedia.org/wiki/Lambda-CDM_model

    "Cold dark matter is ... non-baryonic, dissipationless ... and collisionless (i.e., the dark matter particles interact with each other and other particles only through gravity)."

    There are a few theories that replace dark matter with a modification of either Newtonian gravitation and/or General Relativity. See Cooperstock & Tieu, also MOG, MOND, TeVeS if you feel like swimming in an ocean of math.

    It is also theorized that black holes reside at the centre of each galaxy. As one moves closer to the centre of mass, one can no longer rely on Newtonian gravitation alone.

    Slowly rotating black holes like these are formed by compacting a certain amount of mass-energy M into a spherical volume of radius \(R_s = \frac{\rm{2GM}}{\rm {rc^2}}\) or smaller. This is defined in detail by the Schwarzschild solution. Fun.

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    I could go on until I connect this chain of thought to hot dogs I'm sure, so I'm bailing out!

    [Edit: I don't know what I was thinking when I originally wrote this post. Dark matter is posited to be a halo surrounding the galaxy, thus the pull is outward.]
     
    Last edited: Nov 28, 2007
  15. 2inquisitive The Devil is in the details Registered Senior Member

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    It is easiest to use our solar system as an example. The planets nearer the sun complete one rotation around the sun much quicker than the planets that are near the outside of our solar system. For example, Mercury completes one orbit (rotation around) the sun in about 88 days while Neptune takes about 59,800 days to complete one orbit. The average orbital velocity of Mercury is about 47.9 km/s while the same for Neptune is about 5.4 km/s. What is meant by flat galactic rotation curves is that, unlike the orbital velocities in our solar system, the outer stars travel an nearly the same orbital velocity as the stars closer to the center of the galaxy. The galaxy rotates more like a solid disk rather than the way our solar system rotates. The stars near the outside perimeter of the galaxy travel much too fast according to our understanding of gravity as seen in our solar system. Note: adding unseen mass in the center of the galaxy nor evenly distributed in the galaxy does nothing to correct for flat rotation curves. Most of this unseen mass must be outside the visible galaxy. Either that, or our understanding of gravity is completely wrong when attempting to describe long distance scales, such as in lightyears when modeling galaxy rotation curves.

    One problem with MOND and other such gravity modification theories is that all galaxies do not rotate the same. Some rotate as if there were almost no dark matter around them, rotating more like our solar system. A modification to the inverse square law of gravity that may work to describe one particular galaxy fails when applied to a different galaxy with a different rotation curve.
     
  16. shalayka Cows are special too. Registered Senior Member

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    Yes, I must have been asleep at the wheel there. Thank you!
     
  17. kaneda Actual Cynic Registered Senior Member

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    2inquisitive. If most of the unseen mass is outside the galaxy, why do we not see that in the shape of the galaxy, maybe a halo around a solid centre? The average spiral galaxy is shaped as though there were only the light matter shaping it.
     
  18. Orleander OH JOY!!!! Valued Senior Member

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  19. draqon Banned Banned

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    thats just stupid...

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  20. 2inquisitive The Devil is in the details Registered Senior Member

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    Don't know, unless it's because the Dark Matter mass has replusive instead of attractive qualities.
    Why do mature galaxies change into a spiral shape with distinct 'arms' in the spiral instead of a more homogeneous spiral? Could it be that most of the dark matter inside the galaxy migrates into voids in between the light matter arms because of dark matter's replusive qualities wrt ordinary mass? Just my humble speculation based upon observation.
     
  21. Michael 歌舞伎 Valued Senior Member

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  22. Orleander OH JOY!!!! Valued Senior Member

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  23. kaneda Actual Cynic Registered Senior Member

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    Orleander. Black holes hang onto their mass because it cannot travel faster than light to escape. They grow ever bigger over time (the biggest seen so far is over two billion solar masses).

    There is an explanation on how BH's could lose mass (Hawking radiation) but it is not very likely.
     

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