beyond the universe

Discussion in 'Physics & Math' started by stef 730, Mar 9, 2002.

  1. HubertW Registered Member

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    9
    so following that, galaxies too and all the universe the same I suppose cause the center of univers is a black hole as I have read.

    correct me if Im wrong but as I understand the gravity exists because if the object has a weight bigger then the outside environment, its pulling the metter from outside?
     
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  3. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    I'm not quite sure what you mean about "the object has a weight bigger then the outside environment", but gravity (as far we can tell) is an inherent property of matter. Anything that has matter exerts gravity.
    And the more matter the greater the gravity.
     
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  5. HubertW Registered Member

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    thats what I meant. sorry for not being clear but Im quite new in the subject. each thing that I find poses a lot of new questions.

    so if there is a big black hole in the center of universe, shouldnt all the matter be pulled inside? cause its opposite to what I hear about expanding of the universe?
     
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  7. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    No, common misconception.
    Gravity is gravity. It's only "irresistible" if you cross the event horizon.
    If the Sun (our Sun) were replaced by a black hole of the same mass as the Sun then Earth would still remain in its current orbit. Although, of course, we'd be sat in the dark...

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  8. cosmictraveler Be kind to yourself always. Valued Senior Member

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    Gravity is the key. You may be aware that Jupiter, our largest planetary neighbor in the solar system, is almost all gas (there is a small core of non-gaseous material). Understanding that Jupiter is a ball of gas, wouldn't it be bizzare if it had a shape other than a sphere? Think also of a bubble blown by a child (or your inner child) through a loop. Even very large ones (which are the most fun) seem to seek rest in a spherical shape, even if breezes batter and deform it from time to time. Matter seems to seek to balance internal forces. It would be scary to look up at Jupiter and discover that it had morphed into a doughnut shape or a large tube shape.

    When we are talking about collections of matter that are planet-sized, the same general idea holds. Taking a mass equal to that of the earth, and of similar materials, you could attempt in your mind to construct a pillar with a 1,000 kilometer diameter. But you wouldn't get too far before the pillar's mass would exert so much gravitational force that the whole thing would come crashing in. Even if you braced the pillar while building it, the inner sections would eventually crumble and/or melt long before you finished. Eventually, all the mass would find its way to balance out the gravitational forces.



    Read more: http://wiki.answers.com/Q/Why_are_planets_round#ixzz1HEn8UevO
     
  9. HubertW Registered Member

    Messages:
    9
    hello, You seem quite well informed about all this things. thanx for answering so far. I have another thing that is bothering me.

    light and darkness. theyare like matter and ani matter? canceling one another or they coexist?
     
  10. drumbeat Registered Senior Member

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    375
    Is darkness not just the absence of light though?
     
  11. HubertW Registered Member

    Messages:
    9
    well, what I have read is that darkness has a particles which creates it. the same as light which is made of photons. following Your way of thinking the absnce of mater should be emptiness and appeares that there is antimatter.

    I think the most difficult question of all it to describe what is nothing cause there is always something there.
     
  12. drumbeat Registered Senior Member

    Messages:
    375
    No, hang on.

    My point was that darkness is the absence of light, where as anti-matter is NOT the absence of matter, but a separate entity in itself.
     
  13. Pete It's not rocket surgery Registered Senior Member

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    10,167
    Well, no.
    Darkons were made up as an April Fool's joke.

    "Dark" just means "not much light". Usually, it specifically means "not enough light in the visible spectrum to see with human eyes."

    Like "quiet" means "not much sound".

    "Antimatter", on the other hand, doesn't mean "not much matter". It's something real, with mass, charge, and all other properties of regular matter.
     
  14. pywakit Registered Senior Member

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    In response to the posters who believe we can never know what's beyond our Hubble volume ...

    IF space existed prior to our big bang,

    AND the laws of space are universal,

    AND our Hubble volume is a natural by-product of the laws of space,

    AND space is infinite without boundaries,

    AND other big bangs have occurred throughout eternity and infinity,

    THEN there is at least one way to potentially detect at least some of those big bangs.

    Per GR, those bangs should send out shock waves that would travel in all directions, gradually diminishing with distance.

    These shock waves, propogating out as ripples in space could be detected in the CMB of our own Hubble volume, or perhaps in other ways, especially as our ability to detect faint variations (patterns) increases.

    Roger Penrose et al. just published a paper a few months ago on CMB patterns he believes indicate major events prior to the big bang, which of course suggests space existing prior to the big bang.

    http://www.technologyreview.com/blog/arxiv/26132/

    Steven Feeney et al. just published a paper on CMB patterns he believes indicate 'collisions' with universes outside the Hubble volume.

    http://arxiv.org/abs/1012.1995v1

    And then there is Laura Mersini-Houghton of Chapal Hill ...

    http://quantumconfigurations.com/content/140-dark-flow-evidence-suggests-we-part-multiverse.html

    Was our universe once entangled with a neighbour? The observation of "dark flow" in galaxy clusters was predicted in 2006 by Laura Mersini-Houghton of the University of North Carolina at Chapel Hill and colleagues. She proposes that the effect occurs because our universe was once influenced by neighbouring domains (arxiv.org/abs/0810.5388). neighbouring domains (arxiv.org/abs/0810.5388).

    Mersini-Houghton reasoned that if a force exerted by other universes squeezed ours, it could generate a repulsive effect that would impede the shrinkage of matter into clusters but not leave an imprint on smaller scales. "This skews the distribution of lumps so they are not the same in all directions," she says. There is a preferred direction - the dark flow."

    She also predicted in 2006 that there should be two "holes" - regions with fewer galaxies than expected. Sure enough, there does appear to be a hole - the so-called "cold spot" identified by the WMAP probe. The hole is a very large region of space where the afterglow is cooler than average. However, its cause - and even existence - is disputed, and Mersini-Houghton's hypothesis remains controversial.


    I think it is premature to throw up our hands and state we can 'never know'.
     
    Last edited: Apr 1, 2011
  15. pywakit Registered Senior Member

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    290
    I think you forgot to include the word 'decaying'. Maybe I am wrong.
     

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