Why can't the universe be infinite big?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by pluto2, Dec 17, 2011.

  1. Big Chiller Registered Senior Member


    Do you think the universe may be infinite?​
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  3. AlexG Like nailing Jello to a tree Valued Senior Member

    What do we mean when we say infinite?

    If the history of the universe has a definitive beginning, and has no definitive end, is that infinite?
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  5. Rav Valued Senior Member

    I think there is almost certainly a difference between the universe as we know it, and the true scope of it's reality. That may seem like a pretty obvious thing to point out, but what I'm really getting at is that just because the energy that the universe is made up of is manifesting in the way that it is now, doesn't mean that the beginning of the universe (as we know it) was the beginning of physical reality itself. So the question of whether or not it is infinite, or eternal, really should be considered in that context. Otherwise, we're kinda like fish in the ocean who are wondering if the ocean is infinite and/or eternal, and in realizing that it may not be somehow take that to mean that reality itself may not be.
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  7. river


    the reason the Universe is infinite , is because energy and matter cannot be finite in their existence

    then we get into nothing

    shall we go there again ?

    well if necessary , perhaps some critical-mass of understanding will take hold at some point , soon , in our current history , about this point of view of thinking upon the Universe

    of course the big-bang theory (bb) dosen't help at all
  8. Dywyddyr Penguinaciously duckalicious. Valued Senior Member


    Doesn't help with what?
    What do you suggest we consider?
  9. wellwisher Banned Banned

    The concept of infinity is at the outer limit of space-time. It is where the unification of space-time breaks down allowing space and time to act independently. The speed of light C is consistent within all relative space-time references, and implies infinite size and time period when inserted into the SR equations.

    an observable artifact of an infinite universe would be situations where space and time appear dissociated allowing time to act without space and or space to appear without time. Both of these will appear to occur faster than C. An infinite universe is not just bigger than a finite universe, but it is also between the known laws based on integrated space-time. Once you place limits it is not infinite by default.

    For example, say we had twin particles that were synchronized in time but separated in space. The coordinating signal theoretically between needs to move faster than C. In reality, what we have is excess time (potential) compared to distance (potential). This is not integrated (product = C ) in the same way as normal space-time allowing it to violate laws for space-time. However, it is consistent with laws that govern dissociated space-time and infinity.

    The proof for this is the concept of infinity is a human construct of the imagination, since nobody has any proof for infinity, other than what math says. Since this is imaginary, it occurs within the imagination's matrix, where cause and effect, probability and laws can be violated. it is not part of normal space-time and therefore not constraint to just its laws.
  10. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

    I've never, ever, in my life come across anyone with such a capacity for posting meaningless bullshit before.
    You must practice endlessly.
    Last edited: Dec 23, 2011
  11. Rav Valued Senior Member

    Sorry, but I just can't connect your comments to my own. You're obviously in your own little world.
  12. steampunk Registered Senior Member

    Perhaps your definition of space isn't entirely correct. Perhaps space is not empty. Perhaps it's too small to sense and it is mass.
  13. hucknallite Registered Member

    As it is lacking a clear definition infinity always leads to massive arguments. There are six vague ideas of what infinity may be and a seventh if you want to include the even more vague absolute infinite or God.

    To try and gain a grasp of infinity it is best to begin with it as a mathematical entity. Is infinity a mathematical object. Here we have three candidates. There is the mathematically large which we can represent as the natural numbers. No matter what number we have we can always get bigger.

    There is the mathematically small which is like the Rational numbers. No matter how small we get we know we have a number which is smaller. The third is the notion of the one and the many, where we consider a number line and assume there are an infinite number of ponts on the line. This is the mathematical object we would call the Real numbers.

    As maths like to be absolutely certain about its definitions and assumptions then we get problems with all three mathematical ideas of infinity. It might seem that if we keep going up the Natural numbers then, given enough time we should reach the final – or infinith number. But this would be a mistake. There is no last number, and to assume we can go on forever is to assume the infinite already exists. So we can only prove the infinite as a final number by assuming it is already there. All we are entitled to claim is that for any number we can demonstrate that there is a higher number. The infinitely small gives us the same problem. We can always show a smaller fraction than any fraction we care to name but cannot assume that there is an infinitely small fraction.

    The third mathematical infinity makes a blatant assumption that infinity does exist. Basically, given two points on a line we can assume there are an infinite number of other points between them. Say we have 0 and 1 then there are an infinite number of points between them. In some sense we have to accept this or we would fail to acknowledge the Real numbers, or at least we would be forced to accept that the only Real numbers which existed are the ones we can define.

    It is not clear that any of the three mathematical infinities truly exist as mathematical objects which makes it more difficult to assume the next three exist as they are based on the above.

    The next three infinities to consider are the metaphysical infinities. They are metaphysical because there is no empirical reason to believe they exist. They are based on the three mathematical infinities just outlined. The infinitely large, small and the one and the many. The infinitely large would ask: Is the universe infinite in size? Or maybe even, Can we have an infinite number of grains of sand/planets/stars etc? The infinitely small would ask is there a smallest physical size/space? And the one and the many would ask; Is there an infinite number of moments in a period of time?

    Given the lack of coherence of the infinitely large and small I would answer that the universe cannot be infinite in size nor in time. It is of finite size and will end. (Thats not to say it won't start again, after all if it came from nothing before then it can spring from nothing again.) But if you want to speak of the infinite and whether ot exists then I focus on the one and the many. Infinity exists in the sense that between any two moments of time there are an infinity of other moments.

    This also means that there are as many moments in time during a lunch hour as there are since the beginning of time.
  14. sifreak21 Valued Senior Member

    i honestly dont think we know how big the universe is and it very well could be infinatly big. we dont even know what species lye at the bottom of the ocean but we know there isnt life outside our planet and there is an end to a universe that could be 6000kk light years away.. give me a break
  15. darksidZz Valued Senior Member

    Wat fasccnating gibberish
  16. Rav Valued Senior Member

    If there is only a finite amount of energy, what do you think determined that precise quantity?
  17. Gravage Registered Senior Member

    About stars moving faster than light: stars being further away from each other than they should be, but that's explained away by the claim that empty space is expanding.
    How do they know empty space is expanding? How can you actually see that at all, as far as I know it's just there in steady state? First they need to see if space is expanding at all, if that's not true, than stars are truly moving faster than light.
    And what about the the flatness problem?
  18. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    I thought Krauss was a proponent of the flat universe, and that one outcome of the flat universe is that the universe is potentially infinite? I don't know if he holds to flat AND infinite, or just flat.

    And I thought Olbers' paradox has been explained away by the expansion and age of the universe - i.e. there is an observable universe and beyond this light will never reach us as the distance between them and us is expanding faster than light can travel from them to us.

    One reason I can't get my head round a finite universe is the necessity of a boundary layer... a layer between reality and...??

    And if the universe is flat (zero-energy) then I can't see a reason the universe is not infinitely big.
    If the universe truly is zero-energy, then my question would be if it took zero energy to get to a finite size, why not zero energy to get to an infinite size.
    However, if the universe required net energy then I would have no issue with a finite size (boundary layer excepted).

    As for current size, I know we can see light from 13bn years ago that is now reaching us, and that this observable universe is now something like 45bn LY in radius. And beyond this observable universe is... well, no idea.

    Further, our assessment of the finite/infinte universe is entirely based upon our observable universe. But if our observable universe has just slightly more or less energy than the average of the larger universe then our view of the whole could be distorted. E.g. if the average indicates a flat universe, and our observable universe suggests 99% flat, we might conclude the overall universe is 99% flat rather than the actual.

    Meh, ramblings.

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  19. Rav Valued Senior Member

    Good ramblings

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  20. GASHOLE Registered Senior Member

    ah is eee
  21. river

    okay dywr

    there is no longer energy and matter and space and hence no Universe

    fix it
  22. river

    the idea of infinite and finite

    infinite Universe
  23. wlminex Banned Banned

    . . . how about a (possibly) infinite 'pre-universe' (all dark energy) into which our material universe is 'apparently' expanding as matter is (still) continually created (from pre-existing universe, dark energy). Creation of new matter from the pre-existing state . . . at all points within it (the pre-universe) . . . would give the 'illusion' of expansion from no particular 'center'. This illusion might be due to an advancing dark energy differential ('edge' of observable universe?) due to say . . . 100% dark energy (to start with, in pre-universe)) --> 5% mass (current mass-gravity estimate of observable universe) + 'leftovers' (CMBR, cosmic rays, dark matter?, residual ("unreacted" (virtual vacuum) dark energy, etc.). Since dark energy cannot (yet) be directly detected (observed) and dark matter is only inferred from non-mass gravity requirements (to explain large-scale astronomical effects) my SPECULATION is that gravity in the mass universe is not contributed by dark energy, however gravity from dark matter does contribute. Further, the pre-existing (dark matter) universe has no intrinsic gravity - only energy. The net universe creation reaction might be: Dark energy (subquantum) --> Dark matter (mass universe precursors, + quantum gravity) --> Mass (present, observable universe). (Note in proof: NONE WHATSOEVER!!)
    Last edited: Jan 9, 2012

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