“I want to stand as close to the edge as I can without going over. Out on the edge you see all the kinds of things you can’t see from the center.” -Kurt Vonnegut

We all know how explosions work: a tremendous release of energy causes a rapid outward expansion, and the most energetic particles get flung the farthest and at the greatest speeds. Things fly apart, spread out, and wind up a tremendous distance away. And within our Universe, nothing has ever released more energy than the event that started it all: the Big Bang.

An explosion in space would have the outermost material move away the fastest, which means it would get less dense, would lose energy the fastest, and would display different properties the farther away you went from the center. It would also need to expand into something, rather than stretching space itself. Our Universe doesn't support this. Image credit: ESO.

An explosion in space would have the outermost material move away the fastest, which means it would get less dense, would lose energy the fastest, and would display different properties the farther away you went from the center. It would also need to expand into something, rather than stretching space itself. Our Universe doesn’t support this. Image credit: ESO.

But the Big Bang itself wasn’t an explosion, even if we commonly think of it that way. Explosions have a center, and while there are explosions in the Universe that do display a center, the Big Bang itself wasn’t one. Instead, we need to take on the proper perspective if we want to understand how this all works, and expand not just the fabric of space, but also our minds.

Artist’s logarithmic scale conception of the observable universe. Image credit: Wikipedia user Pablo Carlos Budassi.

Artist’s logarithmic scale conception of the observable universe. Image credit: Wikipedia user Pablo Carlos Budassi.

Take a journey back to the very beginning and better understand how we got to be here today, as we take on the center-of-the-Universe question for Ask Ethan!

Comments

  1. #1 PJ
    Perth, West Oz
    February 11, 2017

    One for Katie Mack !

  2. #2 Dr. Cammy Cheng Fong Quan
    Xiong Onn's family's Traditional Chinese Medicine, KL, Malaysia
    February 11, 2017

    My father died when I was only 12. I used 2 ask all sorts of questions 2 this hermit-guy of my mother’s age, which one of his answers is information on THIS article of yours. SO: Where you write: “Matter being flung away from the center of explosion of the BIG BANG DOESN’T ONLY stretch space”- 4 readers of your THIS article, I would say, the space-size of the Universe:……HAS ALWAYS BEEN IN EXISTENT. BUT: Any object, such as a human being in a rocket, at the time BEFORE the BIG BANG, would not be able to travel through that space, BECAUSE: The MATTER in the whole today known universe was, BEFORE the time of the BIG BANG, in a volume the size of a human eyeball. IN OTHER WORDS: INFINITIVELY DENSE, MAKING THE GRAVITY OF THE “EYEBALL” SO POWERFUL THAT NO MOVEMENT AWAY FROM THE “EYEBALL” WAS POSSIBLE. End

  3. #3 Elle H.C.
    February 12, 2017

    ‘The Big Bang’ is a bad name and should be abandoned. ‘Disturbance of Symmetry’ can be a better name.

  4. #4 Wow
    February 12, 2017

    Where you write: “Matter being flung away from the center of explosion of the BIG BANG DOESN’T ONLY stretch space”-

    Nowhere does it say that.

    Ask your dad to help.

  5. #5 Chris Mannering
    February 12, 2017

    A finite universe has a centre.
    Which may go some way to explaining the extended fling between modern cosmologists and “infinity-dependence”.
    a catastrophe for science…a regrettable but sadly necessary sacrifice, for rubbing the centre right out of existence all together. When we say never again, we mean never again.

  6. #6 PJ
    Perth, west Oz
    February 12, 2017

    @#2
    I very much doubt there were people, let alone rockets before the BB era. Read more of Ethans past topics relating to BB to get a better understanding of the origins of our universe.
    🙂

  7. #7 Wow
    February 13, 2017

    A finite universe has a centre.
    Which may go some way to explaining the extended fling between modern cosmologists and “infinity-dependence”.

    Huh??? A finite age universe has a “centre” and it is wherever you have an observer and a universe that expanded faster than the speed of light.

    There’s no need for any infinity, nor any need to preclude one.

    Not to mention that not only is “infinity-dependence” completely meaningless, you’ve not actually demonstrated it belongs to cosmologists.

    But without it, your “finishing move” there is “flawless failure”.

  8. #8 Sean T
    February 14, 2017

    Chris,

    Two problems with your post:

    1. A finite universe need not have a center. Consider a two dimensional, finite universe that is curved into what we three dimensional creatures would call a sphere. The earth’s surface represents such a hypothetical universe. Within that universe, there is no center. On the surface of the earth, at what point is the center? You may object that the earth does have a center, but that center does not lie at any point within the “universe” of the earth’s surface, so that doesn’t count. A two dimensional creature living on that surface and which cannot perceive a third dimension is in a similar situation to us in a three dimensional universe.

    2. There is no reason to believe that the universe is definitely finite. We simply do not know at this point from the evidence available that the universe is indeed finite. It may well be infinite. We don’t know the important cosmological parameters to enough precision to determine the finiteness of the universe.

  9. #9 John K.
    Ottawa, Canada
    February 14, 2017

    Expanding and becoming less dense – nice. So, as it all expanded from a dimensionless point, then everything in the universe would be the original center, correct? That is, if you went to any point in the universe and played it backward to the Big Bang, you would find yourself at dead center at the Singularity. And playing it forward as it expanded and became less dense, everything else in the universe would seem to be rushing away from you at the center. Correct?

  10. #10 Wow
    February 14, 2017

    Aye, given the assumption it was a singularity (or so small that there was no difference between one point and any other, making the distinction between locations moot.

    Even if it were not, since there’s a limited time to allow light to move from a distant object to us, wherever “us” are, it looks like the center of the universe too.

    And there would be no difference between the view of a real universe or a finite one with an “edge” to define a center (the most distant point from all edges would be a definition of “center”).

    So the simplest and least special explanation; that the universe has no center is the one taken.

  11. #11 Michael Kelsey
    SLAC National Accelerator Laboratory
    February 14, 2017

    @John K #9: As Wow also said, you are correct. If you run the simple (and now outmoded) classical model of general relativistic expansion from a singular point, you’re exactly right that _every_ current coordinate was originally superposed at that singularity (that’s one of the many mathematically ugly bits to being a singularity :-), and hence everywhere in the Universe has equal claim to being “the center.”

    You are also correct that there’s no special “center point” anywhere in the Universe today. Anywhere you could stand, you see the expansion occurring away from you in all directions (after taking account of your local motion relatively to nearby stuff). So wherever you stand, you can make the observational claim that you’re at the center. And so can all those other observers elsewhere.

  12. #12 Chris Mannering
    February 15, 2017

    Wow / Sean ….one or both of you may be right but let’s talk about it. This is my reasoning:

    So imagine a finite universe in however many dimensions you like, of whatever shape, age and whatever extent. let’s suppose for whatever reason the way things work out.

    Let’s suppose we have ‘shape discovery’ technology provided to us by God that absolutely perfectly reveals the shape of the univrse – any finite universe – as if from the outside looking in. In ‘finite’ I’m including all possible instances of universes that have no edge because they are like a surface on a ball, or a doughnut or whatever shape.

    They are still finite ultimately because the technology provided to us on loan from God, can represent that universe…as a doughnut or whatever it is.

    Now, if there is a finite shape, there is always a centre. If it’s a surface of a ball then the centre is the middle of the ball. If that’s a big bang universe then you might object because the expansion is radial, but we don’t have observe the physical laws of that expansion. All we need is representation of the shape that relates the actual shape of the universe at the time of measuring, to a region with9n the shape that corresponds to a centre. There must always be a centre for a finite iniverse. May not be a centre in the dimensions that the internal observer exists, but there will a centre in terms of the shape of the universe.

  13. #13 Chris Mannering
    February 15, 2017

    Michael says “So wherever you stand, you can make the observational claim that you’re at the center”

    Hi Michael – if that’s true and if the universe is flat then it must be infinite in extent. Which is the tacit assumption of most scientists and others who interact with the standard model, if not the model itself (there’s no formalized assertion either way). If on the other hand it’s finite, but still flat, then it turns out not true after all, that all observers find themselves in the centre.

    Another point would be the rest frame of the CMB, which is a specific place in the universe, as it happens just across the way in Taurus. how do you reconcile that reality with the notion there is no preferred centre?

  14. #14 Michael Kelsey
    SLAC National Accelerator Laboratory
    February 15, 2017

    @Chris #12: You have a fundamental misconception here. You are confusing the actual state of a Universe of N dimensions, which may have Riemann curvature in one or more of those N dimensions, with the diagramatic artifice of an “embedding diagram.”

    I highly recommend you read up on Riemann geometry, differential topology, and similar topics related to general relativity, before trying to make mathematical claims which are founded up on naive intuition based on Euclidean geometry in three flat dimensions.

    If you are unwilling or unable to become an expert yourself, and unwilling or unable to understand and respect the opinions of experts in the field, then your opinions merely demonstrate ignorance, not profound insight.

  15. #15 Michael Kelsey
    Michael Kelsey
    February 15, 2017

    @Chris #13: Another misconception. A Universe may be finite in extent, be observationally equivalent from any point, and still not contain any point which can be specially identified as a center.

    One particular, simple example is the topology of a 3-torus, which can be conceptualized as periodic boundary conditions for all three Cartesian dimensions. This is *NOT* a “donut embedded in three space”. It is different, and if you don’t know the geometry well enough to understand what it is, then you should consider deferring to experts.

  16. #16 Wow
    February 16, 2017

    What michael said, with the added note that your misconceptions are deliberately concocted because you’re not here to learn but to troll the shit out of science because it’ too liberal and doesn’t want god everywhere.

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