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Proving that there is one center of the universe.

  1. Mar 9, 2010 #1
    I am attempting to prove with my understanding of physics that the universe must have a center. Here are my premises.

    1) The universe is finite
    The universe had a beginning and we know its expanding, so it cannot already by infinite in size

    2) The universe is flat
    The WMAP satellite measured microwave radiation proving that the universe is flat and not curved back onto itself.

    3) Each observer has their own center of the universe and Hubble's sphere (accepted theory).

    4) In theory if an observer could somehow take a wormhole or a way of transportation to make it to the end of his/her Hubble sphere, then his/her original radius is doubled.

    5) This process can be repeated to infinity.

    6) If each point in space is the center of the universe and space is expanding isotropically, then space must be infinite.

    7) Space is not infinite due to premise 1.

    8) The universe must have and end if its finite, therefore it must have a center in theory if it could be mapped out.


    If the universe is finite, then it must have a quantitative amount of space. Having that said, we should theoretically be able to find an edge of space, since we know space is not curved back onto itself.
     
  2. jcsd
  3. Mar 9, 2010 #2
    and what do you propose would be past the edge?
     
  4. Mar 9, 2010 #3
    Well, I don't know. That is probably the biggest mystery in my mind right now, but that is not the point. There has to be an edge.
     
  5. Mar 9, 2010 #4
    Alright so far....

    Oops! I think you misunderstood something. The issue of the curvature of space has/had to do with whether the universe was open or closed. More than enough matter to close the universe: positive curvature. Not enough matter to close the universe: Saddle-shaped. Just right? Flat.

    The current belief is that the universe is exactly closed, which would mean that the universe would continue to expand, with the rate of expansion slowing. However, about 70% of the universe is dark energy, which apparently causes the expansion of the universe to accelerate. What is dark energy? Even more mysterious than dark matter.

    As to the rest. I won't go into arguments about number of dimensions (10? 11? 40?), but the universe appears to be a hypersphere in at least four dimensions, including the ordinary dimensions of space. So, no matter which direction you go--if you can travel much faster than light--you will eventually return to where you started from.
     
  6. Mar 9, 2010 #5

    Chronos

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    The universe is observationally and temporally finite, that does not mean it is provably finite in either respect. A wormhole would not solve this problem. You would still be unable to distinguish the edge from the center of whatever universe of destination.
     
  7. Mar 9, 2010 #6
    You would never be able to reach the edge, since space-time is not constrained by special relativity. So when you reach the old edge, the new edge is far, far away.
     
  8. Mar 10, 2010 #7
    I have wondered about this as well. what defines the edge (if it exists).

    A couple of things come to mind.
    1/ everywhere light reaches is space.
    2/ everywhere gravity effects is space

    If the universe is expanding at less than the speed of light. What happens to light when it reaches "the edge"? my guess is there would be an infinite impedance mismatch. this would create a reflection (not just light but all energy).

    The upshot of that is if we looked at the right place in the universe we may see our own reflection. It also begs the question. Is the universe is smaller than we think? Are we are stuck in some sort of hall of mirrors?

    CC


    P.S.
    It saddens me the number of edge deniers out there. they must work for the oil companies or something.
     
  9. Mar 10, 2010 #8

    Ich

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    1) no
    2) seems so
    3) ok
    4) Huh?
    5) what process? (if I understood what you mean: you travel 1000 km a day. You can travel for as long as you want. Therefore earth's surface is infinite).
    6) no
    7) no
    8) no

    In our current model, the universee is spatially infinite. That doesn't mean that it really is infinite, but it certainly leaves the possibility.
    Even if it were finite, there could be no border or center. Just as for points on the earth's surface.
     
  10. Mar 10, 2010 #9
    There is no edge that light can reach. The balloon analogy is not good, but it is probably the best available. Think of an ant crawling on the surface of an inflating balloon. Even if the ant continues in a straight line, it will never get to an edge--or return to its starting location. So if there was an edge, it would be moving away from everywhere at faster than the speed of light.

    Now imagine a hyperballoon in a hundred-dimensional manifold. When you start to inflate it, it chooses a few dimensions in which to expand and collapses in others. That is the inflationary period right after the big bang. The universe is still very small in the three space dimensions at the end of the inflationary period, but it was so rapid that light could not get from one part of the balloon's surface to any other. Even 13-14 billion years later, light still hasn't had time to get a significant fraction of the way around the balloon's surface. And it never will. (Yes, I know, light couldn't get far for the first few million years, until the universe cooled enough. But that is detail.)
    It is just the way the math works. If you want to get out of the universe, choose one of those rolled up dimensions, and move a few millionths of an inch in a straight line. ;-)
     
  11. Mar 10, 2010 #10

    What are you talking about? If the universe is flat, you will never come back to the point where you started. That is in the closed universe model. I have done my research and have found no evidence supporting that the universe is closed back onto itself creating a never ending loop. Could you provide me with some?
     
  12. Mar 10, 2010 #11
    All joking aside the above raised a couple of concerns, and sorry for the off topic stuff.

    Firstly on my initial reading you seem to be saying that after the big bang the universe grew faster than the speed of light! Or perhaps you are saying it expanded at the speed of light?

    Secondly as the universe cooled where did the heat go?

    And on topic.

    Isn't the centre of the universe the point of origin?
    If the big bang didn't cause the universe to inflate in all directions at the same velocity then what constrained it? One would assume that the nothing that didn't exist outside of the singularity could not control the direction of the explosion/expansion. I know its an assumption, but one would assume the singularity itself would have been uniform in its singleness. If one could use such a phrase. So the expansion should occur in an even manner.

    Only after matter started to coalesce would the universe take on a shape that appeared to be other than uniform. even then space itself should be uniform its just the visible universe that may appear ragged.

    Lastly Why do cosmologists consider the universe to be an expanding balloon. what gives rise to that theory. in its simplest form that theory would indicate that the edge of the universe is just above our heads. and the edge of "inner nothing" is somewhere below our feet.

    And sorry I am not a fan of explaining things away by calling it another dimension. that to me is the equivalent to the 'god of the gaps'. I.E. if you can't explain something throw in god, or in this case another dimension.

    I much prefer to say we don't know just yet but we will get to that. otherwise its a case of making the maths fit the answer.

    If the answer is 2 what's the question?
    1+1 ?
    no wrong its 1 + (dimension X)^(1/0) + 42 = 2

    Just doesn't gel with me.

    CC
     
  13. Mar 10, 2010 #12
    I found an interesting article
    http://curious.astro.cornell.edu/question.php?number=71 [Broken]

    In essence it says each and everyone of us is the centre of the universe. that the universe is expanding in all directions at once. not from a single point like one would expect in an explosion. in other words space is expanding not the universe. it also says there is no 'edge' because the universe occupies everything everywhere.

    At least that's how I read it. And I don't pretend to understand it.

    CC
     
    Last edited by a moderator: May 4, 2017
  14. Mar 10, 2010 #13

    Chronos

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    Correct, all observers are at the edge of their observable universe, All they see is their past.
     
  15. Mar 10, 2010 #14
    Do you think that dark flow could be a piece to this puzzle? Not only are these galaxy clusters moving against dark energy but they are all heading to the same spot - a point between the constellations Centaurus and Vela. Could these renegade clusters be heading for the center of our galaxy?

    Perhaps the universe is a flat torus and these clusters are the first arrivals to make their way back to the center.

    Perhaps our universe is one in a multiverse and these clusters are leaving the center of their universe and heading towards the center of ours.

    Whatever the case, I think dark flow is a vital clue and evidence that there may be a center to our universe.
     
    Last edited: Mar 10, 2010
  16. Mar 11, 2010 #15
    Draw a circle on a piece of paper. If the paper is flat, there are 360 degrees to the circle. Or better, the circumference is Pi times the diameter. If the circumference is less than Pi times the radius, the paper is not flat. It might be the surface of a sphere. If the circumference is greater than Pi times the diameter, the paper is saddle-shaped.

    This is the sense in which the universe is flat. (Well, when measured well away from black holes or some other source of gravity.)

    Now let's look at space near a black hole. If, right at the event horizon you shine a beam of light in the right direction--it will hit you in the backside. If you ask the beam of light, it will tell you, that of course it went in a straight line--it doesn't know how to do anything else.

    Hop in your superluminal space ship, fly straight ahead for long enough, and you will be able to talk to the light beam again, still going straight ahead--and around and around the black hole.

    The problem/trick is that you can't separate the observer from the space he or she is embedded in. Lines which appear straight to those in the space can be understood to be curved by anyone outside that universe.
     
  17. Mar 11, 2010 #16
    Much faster than the speed of light. The Inflationary epoch lasted much, much less than a second, and the universe inflated by a factor of at least 10^26 in length, width, and depth. (see: http://en.wikipedia.org/wiki/Inflation_(cosmology))
    See any physics or chemistry book and look up adiabatic expansion. If you want to think of the compressed hot universe doing work expanding the universe, fine. The net effect is that as the universe expands, and particles (including photons) move further apart, the measured temperature drops. You can also see this in cosmic red shifts.
    Lol! But not at you. If the universe originated in some other universe, or multiverse, it is still at the same address. In fact, all the contents of the universe are still in that one point--in some other co-ordinate system, universe, set of dimensions, what ever you want to speculate existed before the big bang.
    Get one of those long skinny balloons (again with the balloons! ;-) When you start to inflate it one section will suddenly start to grow. Then as you put more air in this section gets longer. The same sort of physics applies to dimensions right at the big bang. Once energy is going in to inflating (ouch!) some dimensions there is less pressure on others and they stay rolled up.
    You have to keep track of the dimensions. We know that the universe is expanding in the three dimensions of space. Various string theories have additional dimensions and branes, etc. But that doesn't affect this discussion. The balloon is a two dimensional analogy of the three dimensional expansion of the universe. Forget that the balloon has three dimensions--the two-dimensions measured on its surface represents what happens to the three dimensions of the universe.

    So the surface of the balloon is not under your feet in the x,y,z, or t dimension. But it will be in w or q or maybe 42. Now all you have to do is figure out how to take measurements in that dimension, and you too can have a Nobel prize.
     
  18. Mar 11, 2010 #17
    Obviously, the various different "big bangs" that would form a multiverse ARE in the same universe. I don't think the word is intended to be taken that literally. I'm neither for nor against the idea of a "multiverse", but it is an idea taken seriously by many professional cosmologists and dismissed by others.

    http://www.newscientist.com/article/mg20126921.900-dark-flow-proof-of-another-universe.html

    A multiverse would certainly work with the brane theory. But whether a multiverse is true or not was not the point of my post. My only point was that there are galaxy clusters moving against all the others and towards the same point in space. Be it from a multiverse, a 3-torus or whatever, the fact that this is happening suggests that there MAY be a center that they are moving towards.
     
  19. Mar 11, 2010 #18
    Trying to respond to the original question:

    Premise 2: surely means that space (not the universe itself) is "flat" or "linear" not "curved".

    Premise 4: surely not doubled, only 1.5 x in a linear direction ?

    Premise 5: Unless there is space beyond the edge of the universe, even given (way !) above lightspeed travel, you could only reach the edge of the expanding universe and follow its expansion at the speed of light.

    (But then again, if you could outrun it, you would be increasing the expansion of the universe !)
    (Or if you then exceed 2C, would you be going off in a little expanding bubble of space ? Creating another "universe" outside this one ?)

    The Big Bang theory surely assumes that the universe originated from a definite point in space (even though it was the only point in space that existed at that instant)(and assuming that the Big Bang created all of what we now call space).

    If the Big Bang emitted light from that instant, then the radius of the universe must be equal to the age of the universe multiplied by the speed of light (assuming the universe is expanding into nothingness, and is thereby creating more space (at a necessarily increasing rate) as it goes). Light from the Big Bang is progressively expanding the universe by continually creating more space (at the speed of light), and that light is continually creating the ever expanding "edge" of the universe.

    Unless they've changed the theory without telling me, there is no space outside the universe. It must have an "edge", but doesn't have an "outside".

    The centre of the universe must still be in the same place it started off, equidistant from all points on its spherically expanding outer perimeter.
    (Assuming the light from the Big Bang expanded in all directions.) (There must be a very big dark hole there by now.)
    (Mustn't there ?) ;)
     
  20. Mar 11, 2010 #19
    The question is, Is there enough matter in the universe to make space curve into an infinite loop as you just described with light in a black whole. If there is, shouldn't there also be enough mass to have a greater escape velocity then recessional velocity of the WHOLE universe?

    This is why I am not convinced there is. If there is enough matter to curve space to trap the matter itself, it should surely have a greater escape velocity then recessional.
     
  21. Mar 11, 2010 #20
    Those that don't browse the "Cosmology" section of the forums might be interested to know that there is a current thread there discussing this very same topic entitled, "Center of the universe".
     
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