Why the universe has to be so big?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Saint, Oct 29, 2017.

  1. Saint Valued Senior Member

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    3,373
    Any specific reason that the universe must be so huge?
    Billions of galaxies ans trillions of stars.
    And we only live in a dust - earth.
     
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  3. Seattle Valued Senior Member

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    Does there need to be a "reason"? Why does a grain of sand have to be so small? It just is.
     
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  5. DaveC426913 Valued Senior Member

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    6,987
    Because it's so old.

    It wasn't always this huge. Once, it was ... smaller.
     
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  7. Michael 345 Valued Senior Member

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    3,507
    No reason
    No purpose
    No grand design
    No heaven
    No hell
    No god

    Lots and lots and lots of stuff
    Really lots of stuff
    The icing on the cake
    Life
    The cherry on the icing
    Sentient life
    The cherry on the cherry
    We are free range sentient life (sure bound by physics, but so is the rest of the Universe)
    But we have no boss (other than physics) and since physics is a equal neutral enforcer of the rules we cannot claim being picked on for different treatment

    Ain't it grand?

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  8. Saint Valued Senior Member

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    it just happens by chance?
    no cause and effect?
    Against Science, since primary school, teacher taught me everything must have cause and effect.

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  9. sweetpea Registered Senior Member

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    Shouldn't that be... Against your understanding of science?
     
  10. origin Trump is the best argument against a democracy. Valued Senior Member

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    Cause and effect have nothing to do with your observation that the universe is big compared to the Earth. The Earth is big compared to a grain of dust. No cause and effect just an observation.

    Why is the universe so big? Why not?
     
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  11. geordief Registered Senior Member

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    578
    When something "just is" our attempts to do other than take note may be doomed to failure.

    We may ,based on previous experience say to ourselves "there must be some mistake" but ,until we find a flaw in our observations then we are more or less obliged to shoehorn our previous observations into the new overall picture.

    There may be patterns in the sum of pictures we have seemingly uncovered but there is unlikely to be "one picture that rules over them all".
     
  12. Gawdzilla Sama Registered Senior Member

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    576
    There's a theory that our Big Bang was a "white hole" into this universe connected to a black hole in another universe. If so then perhaps some super massive black hole created this universe from junk in its own universe. It would follow, then, that each SMBH in this universe is creating another universe, and the SMBHs in that universe would carry on. When you get to thinking of the scale of things, when perhaps millions of SMBHs in our corner of the Cosmic All is leading to the creation of another universe, we don't seem to be all that large at all.
     
  13. DaveC426913 Valued Senior Member

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    6,987
    Not by chance, no.

    By physics.
     
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  14. C C Consular Corps - "the backbone of diplomacy" Valued Senior Member

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    We're here, with our bodies / brains producing perceptual and reason-based evidence that the cosmos exists (in contrast to the mindless, not-even-nothingness which it otherwise is to itself). As well as generating what seems like endless understandings of the world. What type of universe and how large does that "we're here" require in order to be the case? Would abiogenesis and evolution (i.e., life) have any chance of occurring if there was only a handful of stars and planets? Complex life and intelligence arising require yet another order of vast, dead prospects to increase their probability (you can't call those "failed attempts" since there's no agenda or teleological goal to produce life or sapience to begin with).

    But is that vast number of galaxies overkill in terms of explaining and accounting for how "we're here" haphazardly? Time will tell for the posthuman, self-replicating smart machines prowling slowly and immortally over the Milky Way for eons to come. If they never find another past or concurrent instance of technological and philosophical oriented creatures but the ancestral ones that engineered them, then the overkill might not really be such, or as great.

    - - -
     
  15. timojin Valued Senior Member

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    3,172
    As the people who model the big bang . Prior Big bang was it big or small, since science talks about expansion it implies to be small.
    Do we know anything , if there was a beginning .
    Saint you have a good question.
     
  16. DaveC426913 Valued Senior Member

    Messages:
    6,987
    We know nothing about the epoch pre-Big Bang. Could be big, could be small, could be no dimension at all.

    Shortly after the BB, the universe was small (much smaller than an atom). We don't know what it as at the BB.
     
  17. geordief Registered Senior Member

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    578
    If that is true** ,should it be qualified as being small in comparison to what it is now? There is no such thing as absolute smallness is there?

    ** not to deny it ,as I do not have that knowledge.
     
  18. Gawdzilla Sama Registered Senior Member

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    576
    You're asking questions that astrophysicists struggle with. You're in good company.
     
  19. DaveC426913 Valued Senior Member

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    6,987
    Well, there were things around then that are still round now - such as photons, which have a speed and frequency - so the universe diameter could be absolute. True, c might have been different back then, but I think that's a different question.
     
  20. Janus58 Valued Senior Member

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    1,802
    And for all we know, the same laws of physics that eventually allowed for our existence also, by necessity,led to a universe the size and complexity we see. Maybe you couldn't have had the first without the second.
     
  21. Seattle Valued Senior Member

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    2,241
    Astrophysicists don't struggle with questions like this.
     
  22. Michael 345 Valued Senior Member

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    Just on this point I was thinking recently about the speed of light from another area of my reading. The question was asked why is the speed of light the particular speed it is ie why not 10klm faster or slower

    Then it struck me from a remark made it HAS to be the exact speed it is. It is a inbuilt feature and cannot be otherwise

    Consider E = mc²

    We know Energy cannot be created or destroyed so it would appear what the total energy content of the Universe has ALWAYS been such (in different forms sure) but in total always the same

    So extracting the energy from mass by the formula E = mc² will always provide the same amount of energy from the same amount of mass

    And that will happen ONLY if the speed of light remains invariant

    I'm still trying to refine the thoughts about this into more explanatory terms (rather than mathematics) but it appears to me at the absolute bedrock of physics would be the speed of light

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  23. DaveC426913 Valued Senior Member

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    It is not an unreasonable interpolation that, if the early universe were such that the value of c could change, then so could the measurement of energy.

    I was simply putting forth the idea of a variant c as tying up any loose ends in the argument that c can be used as a measurement.
     

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