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Thread: Galactic Collisions

  1. #1 Galactic Collisions 
    Forum Radioactive Isotope zinjanthropos's Avatar
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    As space expands and the galaxies become farther and farther away from each other, there are still some on collision courses. As expansion continues will these type of interactions decrease significantly? As one galaxy approaches the other does the space between them continue to expand and what causes a galaxy to head towards another galaxy despite space expansion? Although it may take billions of years, could a galaxy currently about as far away from us as we can see ever get on a collision course with our galaxy?


    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
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    Anti-Crank AlexG's Avatar
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    Any galaxy further away than 200 million lys will be receding. Galaxies closer together than 200 million lys are gravitationally bound to each other, and could be on collision courses. (i.e. the Milky Way and Andromeda)


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    Forum Radioactive Isotope zinjanthropos's Avatar
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    Quote Originally Posted by AlexG View Post
    Any galaxy further away than 200 million lys will be receding. Galaxies closer together than 200 million lys are gravitationally bound to each other, and could be on collision courses. (i.e. the Milky Way and Andromeda)
    Now when you say recession are you saying the receding galaxy is actually moving away or it's just space expanding between them and us?or a combination of both?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
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    Anti-Crank AlexG's Avatar
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    Space expanding between them.
    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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  6. #5  
    Forum Radioactive Isotope zinjanthropos's Avatar
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    Quote Originally Posted by AlexG View Post
    Space expanding between them.
    Maybe I'm missing something here but a galaxy closing in on us is actually moving, is it not? or at least one of the galaxies is moving? Moving at a rate faster than space can expand?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
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  7. #6  
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    Last edited by Chucknorium; May 13th, 2014 at 09:38 PM.
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    Anti-Crank AlexG's Avatar
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    Moving at a rate faster than space can expand?
    No, expansion cannot manifest unless the objects are not gravitationally bound. If they are bound, we see no expansion. Galaxies closer together than 200 million lys are bound with a gravitational attraction which is stronger than the expansion of space.
    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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  9. #8  
    Forum Radioactive Isotope zinjanthropos's Avatar
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    Quote Originally Posted by AlexG View Post
    Moving at a rate faster than space can expand?
    No, expansion cannot manifest unless the objects are not gravitationally bound. If they are bound, we see no expansion. Galaxies closer together than 200 million lys are bound with a gravitational attraction which is stronger than the expansion of space.
    Thanks for answering Alex, appreciate it.

    But they were all gravitationally bound at one time, no?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
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  10. #9  
    Anti-Crank AlexG's Avatar
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    No. In the early universe there was no clumping of matter yet, gravity was too diffuse to cause gravitational binding.
    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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  11. #10  
    Forum Radioactive Isotope zinjanthropos's Avatar
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    Disclaimer: I don't believe the following statement, just throwing it out there.

    Imagine for a moment that ours is not the only universe. If so then could universes collide? If there is more than one and they bumped into each other what should we observe? Is there any evidence that may suggest such an event has taken or is taking place?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
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  12. #11  
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    Quote Originally Posted by zinjanthropos View Post
    Disclaimer: I don't believe the following statement, just throwing it out there.

    Imagine for a moment that ours is not the only universe. If so then could universes collide? If there is more than one and they bumped into each other what should we observe? Is there any evidence that may suggest such an event has taken or is taking place?
    Some researchers believe that a multi-verse, or a parallel universe does exist. And apparently the (alleged) direct evidence of primordial gravitational waves discovered by the team at the BICEP2 telescope facility in Antarctica lends credence to this idea. In a multi-verse, each universe would potentially have different laws of physics. Also, it's possible a living creature would inhale something other than oxygen and exhale something other that carbon dioxide.

    From Wikipedia: Multiverse - Wikipedia, the free encyclopedia
    Around 2010, scientists such as Stephen M. Feeney analyzed Wilkinson Microwave Anisotropy Probe (WMAP) data and claimed to find preliminary evidence suggesting that our universe collided with other (parallel) universes in the distant past.[22][unreliable source?][23][24][25] However, a more thorough analysis of data from the WMAP and from the Planck satellite, which has a resolution 3 times higher than WMAP, failed to find any statistically significant evidence of such a bubble universe collision.[26][27] In addition, there is no evidence of any gravitational pull of other universes on ours.[28][29]
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  13. #12  
    Forum Radioactive Isotope zinjanthropos's Avatar
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    Quote Originally Posted by JustinLG View Post
    Some researchers believe that a multi-verse, or a parallel universe does exist. And apparently the (alleged) direct evidence of primordial gravitational waves discovered by the team at the BICEP2 telescope facility in Antarctica lends credence to this idea. In a multi-verse, each universe would potentially have different laws of physics. Also, it's possible a living creature would inhale something other than oxygen and exhale something other that carbon dioxide.
    This is purely the uneducated layperson cosmologist in me talking..... Now I often hear talk that the universe goes on forever but is there any possibility that at some point(s) in the unseen infinite boundlessness that another universe is expanding in the same way as ours? What I mean is: Could more than one universe share a common ground, by that I mean this vast never ending space and eventually combine or at least affect one another?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
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  14. #13  
    AI's Have More Fun Bad Robot's Avatar
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    Quote Originally Posted by zinjanthropos View Post
    Quote Originally Posted by JustinLG View Post
    Some researchers believe that a multi-verse, or a parallel universe does exist. And apparently the (alleged) direct evidence of primordial gravitational waves discovered by the team at the BICEP2 telescope facility in Antarctica lends credence to this idea. In a multi-verse, each universe would potentially have different laws of physics. Also, it's possible a living creature would inhale something other than oxygen and exhale something other that carbon dioxide.
    This is purely the uneducated layperson cosmologist in me talking..... Now I often hear talk that the universe goes on forever but is there any possibility that at some point(s) in the unseen infinite boundlessness that another universe is expanding in the same way as ours? What I mean is: Could more than one universe share a common ground, by that I mean this vast never ending space and eventually combine or at least affect one another?
    I don't see why not, also if we live in a multi-verse I would think they would all follow the same rules of nature and be very similar to each other. Whatever causes a big bang expansion would be operating in a cosmic structure so big as to be out of our range of perception. After all we can't even see to the edge of our local universe.

    However we have observed something called the "Dark Flow" which seems to be proof of something outside our universe affecting the movement of many thousands of galaxies. See the link below and follow the progress of theories to account for the observation.

    Dark Flow: Tugs from Beyond the Observable Universe? - The Nature of Reality
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