The Universe May be Different Than Previously Thought

Posted by Greg Laden on September 26, 2008
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If confirmed, a recent finding may be one of the more interesting outcomes of cosmological research in quite some time. Possibly interesting enough to keep everyone busy while they are retooling the Large Hadron Collider.

First a bit of background. Assume the big bang happened. When we look out at galaxies near and far we find that they are all moving apart in exactly the way we would expect them to be moving if the entire universe was expanding. The nature of this expansion is a bit spooky, and there is more than one way to describe it (not necessarily alternative ways). But the bottom line is that the Universe in which we live … the one to which the rules of physics are expected to apply uniformly, the one containing all the things you could possibly visit if you had a Star Trek style starship … is much larger than we can see, about 16 or 17 billion years or so (maybe as old as 20).

(You will see different estimates, and they often differ because of different meanings and methods, not so much different facts or opinions. Since the measure of time is somewhat illusory, saying how old something that existed since the beginning of ‘time’ is difficult. We see back in time about 13.7 billion years, but ‘cosmic expansion’ allows light to have reached us from ‘before’ that point in time, which means that the universe is older than our observable universe. There are other reasons to suspect an older universe as well. None of this is too important to the present discussion.)

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But here’s the thing. We thought everything was moving and/or expanding uniformly in all directions, as though a) the galaxies of the universe were like dots on a big, uniform rubber surface being stretched out so that all the dots grow more distant from each other and b) that that was pretty much the whole story at the largest scale.

Now there is evidence that there is a tugging effect on the known, visible universe. Galaxies are organized into clusters of galaxies, and these clusters are are all moving away from each other like they are supposed to, but they are ALSO moving towards something else. A place that is estimated to be beyond the known universe.

The picture above is the well known map of the background microwave radiation that comes from the origin of the universe and that has been subsequently altered by various relativistic effects. The pink blob is the place out there in the sky somewhere, but beyond the visible range, to which everything is being tugged, slightly.

What could possibly be out there, beyond the Universe, tugging on us?

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Details here.

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Comments

  1. #1 themadlolscientist, FCD
    September 26, 2008

    Once again, it has been verified by direct observation that the universe sucks.

    Sorry, couldn’t resist. =^..^=

  2. #2 Duae Quartunciae
    September 26, 2008

    You say: is much larger than we can see, about 16 or 17 billion years or so which seems to be using years as a measure of size. That can make sense in some contexts, but not for asking how far the universe extends beyond the observable horizon, I think.

    The “observable” universe is the region from which photons could reach us (in principle) over the lifetime of the universe; but the regions that are more distant are no older than our local region (in conventional models).

    The universe is probably much much MUCH larger than the observable universe; particularly in inflationary models; which involve an early period of very rapid expansion that carry most of the universe far beyond the observable horizon. But this does not (necessarily) involve additional age.

    The page you cite does not actually give any reasons for thinking the universe is significantly older than the 13.7 billion years obtained from the parameters of about 30% matter (mostly dark matter) and 70% dark energy.

    In some of the weird and wonderful ideas for cosmology, there can be multiple expanding domains, and in that case you can have different ages. But we don’t “see” them; they are not part of “our” universe than we could visit given an Enterprise. And in particular, I think “‘cosmic expansion’ allows light to have reached us from ‘before’ that point in time” is not correct.

    Sorry… I know you listed this as “not too important”! The flow effect you describe is indeed intriguing.

  3. #3 greg laden
    September 26, 2008

    Well, that was an utter failure… as you note, my parenthetical remark is an aside, not a salvo in some major debate. The age estimate I give is not related to the question of the size of the “universe.”

    What is much more important here is that for there to be a big pink blob tugging on the galaxy clusters, the basic plan for what the universe looks like, how it is shaped, what it looks like, ans possibly it’s size must be wrong in some important way. Yes, very interesting! (If verified.)

  4. #4 Mike Haubrich, FCD
    September 27, 2008

    I have read estimates that the universe, if measured in 3 dimensional space, is approximately 47 billion light years across (whatever that means.) I think that the estimate is based on the redshift of the farthest visible objects, and an estimate on how much the universe has expanded since their light began its journey towards us.

    I only went so far in my physics studies, and so it is all rather confusing to me.

  5. #5 Jonathan Vos Post
    September 27, 2008

    20 years in the Space program, 1 year as an Adjunct Professor of Astronomy, and this semester I’m explaining The Universe to 9th, 10th, and 11th grade impovershed students.

    I’ve been telling them the basic notions of the Big Bang, and 4 categories of problems with the model. Now I need to add a 5th problem with the model.

    Their level of sophistication is fairly low, in that roughly 1/4 of them told me on homework assignments that they consider Pizza to be a compound.

    We’ll see what happens when I mention this, next week.

  6. #6 Confused Student
    September 27, 2008

    Wait wait. Are you saying that Pizza is not a compound?

    What about garlic sticks. That’s a compound still, right?

  7. #7 Mark
    September 27, 2008

    fact is…these numbers are too big for most of us to comprehend (me inculded!)…but fascinating none-the-less.

  8. #8 Betul
    September 27, 2008

    Any theory that potentially puts the previous one in danger, is exciting to me..

    But I always knew cats had some metaphysical powers beyond our understanding!

  9. #9 CEILING CAT
    September 27, 2008

    IS BEN DE-TECTED. NEOW U MUST ALL DYE

  10. #10 Ben Abbott
    September 27, 2008

    As what the phenomenon might be, we apparently can only observed the effect on other galaxies.

    It is unclear (to me) that the object is close enough to use that it can even have an impact on our galaxy … it may be beyond the event horizon imposed by our recession velocity.

  11. #11 Ben Abbott
    September 27, 2008

    “IS BEN DE-TECTED. NEOW U MUST ALL DYE”

    opps, I missed that comment ahead of my own :-(

    Sorry for all of you, but on the upside it appears that “BEN” will not “DYE” ;-)

  12. #12 speedwell
    September 28, 2008

    It’s the “Great Attractor,” a previous discovery:

    http://csep10.phys.utk.edu/astr162/lect/gclusters/attractor.html

  13. #13 yogi-one
    September 28, 2008

    I don’t anything, but hearing some scientists claim that they know how big the universe is and that they have already mapped it….well….

    My neighbor’s cat has mapped the neighborhood, so he knows everything that goes on in it. That feline practically predicted everything McCain was going to say. He also knows when my car needs a tune-up. I think he’s the one that keeps the garbage men from coming on their appointed day every week…Man that cat has sure figured everything out about his universe, that’s for sure!

    So, yeah, we know the whole universe because we’re the most evolved beings ever to live it.

    Gee- God must have planned it that way, huh?

    There’s a big pink blob out there attracting us and it’s comprised of …KIBBLES! Yummy..we have to get to it!

  14. #14 David Canzi
    September 28, 2008

    If direct light from the attractor hasn’t had time to reach us, but light from the galaxies affected by it has, then whatever force from the attractor has affected those galaxies must have travelled faster than light.

    Unless I’m missing some relevant knowledge that physicists know about, that would be a revolutionary discovery.

    There have been many more announcements of revolutionary discoveries than there have been revolutionary discoveries.

  15. #15 greg laden
    September 28, 2008

    First, I’m pretty sure the attracting force is working on our galaxy cluster as well. (I’m not sure that has been clear in this discussion).

    This all depends on what gravity really is. A particle, even a massless particle, cannot move faster than the speed of light. However, particles (of mass or energy) are manifestations of things that you could call waves. If the thing that the wave is in becomes wavy, then the waves are everywhere. And if a particle can arise from a wave, and disappear into a wave (which they do) then a thing can disappear in one part of the universe and appear in a different part of the universe simultaneously. Holding that thought in mind…

    Consider that if gravety is what warping of space time, it may be the case that the warping does not propagate, it just is. The effects of gravity are spontaneous. Changes in gravity may be propagated by particle/waves, and thus limited to the speed of light if they are moving across space. But since gravity is an aspect of spacetime, it may be hard to see how it moves across space. There is not a theory that has been accepted that explains this.

    Then, there are two other totally different explanations. The most extreme is that there is no attracting force, but rather, a skew in the movement that is not caused by some giant cat (or whatever) but rather by some oddity of the big bang. Or something like that.

    The other, and more likely, is that the attracting mass is dark matter and it is not beyond the range of our known universe. But since it is dark we don’t see it.

  16. #16 Jonathan Vos Post
    September 29, 2008

    All the students tested agreed that Taco Salad was a mixture.

    Many of the students tested who thought that Pizza was a compound also thought that Beef Stew was a compound.

    My wife (a Physics professor) suggested that the students thought that the melted cheese of pizza and the gravy of the beef stew held things together tightly enough to make a compound.

    Dr. George Hockney at JPL agreed that their confusion about binding strength meant that I needed to give them a chart or diagram, as mere spoken and printed words had not sufficed.

    So I gave them a tree diagram of “classification of matter” and a flow chart of what questions to ask to decide whether a substance was an element, compound, or mixture. They may also be baffled by what is a physical method of separation and what is a chemical method of separation.

    Then I waited a day and gave a quiz.

    About a third of the students stated that the Periodic Table listed elements and compounds. The ones that I marked wrong with a red X also had my comment: “The Periodic Table of the Elements” which is also what it says on the inside back cover of their textbooks, which my other homework and test questions forced them to examine.

    The fraction of students who call Air and Water elements has diminished to about 1/5. Maybe I never should have mentioned Earth, Air, Water, and Fire in the first week. They latched on to that paradigm, and wouldn’t let go even when I pointed out that Asian alchemy classified Wood as an element.

    And it blunt my joke that we used to believe that the universe was made of 4 elements: Earth, Air, Water, and Fire. But now we be believe that the universe is made of 4 more sophisticated things: matter, dark matter, energy, and dark energy.

    So you see why I wonder what will happen when I say that some part of our universe seems to be attracted to something beyond our observable universe.

    My wife pointed out that this is about right for a story in Analog…