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Space Science

Motion of the Primordial Universe Revealed 63

Posted by michael from the hot-and-bothered dept.
neutron_p writes "New results from an instrument located high in the Chilean Andes (the Cosmic Background Imager) are giving researchers a clearer view of what the universe looked like in the first moments following the Big Bang. Cosmologists observe a time in the universe's distant past when atoms were first forming. The findings reveal the first movements between these "seeds" that ultimately led to clusters of early galaxies."
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Motion of the Primordial Universe Revealed More

Motion of the Primordial Universe Revealed

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  • Reading the article (Score:3, Funny)

    by tod_miller ( 792541 ) on Friday October 08, 2004 @11:41AM (#10470941) Journal
    New data suggests that the universe expanded rapidly in the first instants after the Big Bang

    Which lead to renewed enthusiasm about the name, as apposed to previous suggestions:

    The Big Yet Apathetic And Lethargic Singlular Point Of Spontaneous Existence Creation By Magic.

    I believe that the Big Bang we hear are echoes of cosmic events that may have happened anywhere. I also think that there was a real bang, when reality and existence in thier mortal plane was created.

    If you think that is more crazy than an inexplicable universe full of toothpicks, then please by all means explain yourself.
  • It's just a jump to the left and then a step to the right.
  • The artivel mentions nothing of the motion that is claimed in the Headline. Sure, it talks about what the results of their analysis of that motion is: support ofr Dark Matter and Dark Energy. Great. So what is this new understanding of motion they discovered.?

    Anthony Readhead.... says the new polarization results provide strong support for the standard model of the universe as a place in which dark matter and dark energy are much more prevalent than everyday matter.

    THank you Mr. Readhead, and now

  • This has always confused me (Score:3, Interesting)

    by El ( 94934 ) on Friday October 08, 2004 @12:21PM (#10471517)
    Don't microwaves move in a straigth line? In which case, shouldn't any radiation created by the big bang be at least 13 billion light years away from it's point of origin by now? So, unless they are reflecting off something or the universe wraps around at the edges, why can we still detect them? If they are reflecting off something, then aren't they really just mapping the density of whatever they are reflecting off of? I guess I'm just not clear on what makes this background radiation run around in circles...
    • First thing, Microwaves and all Light do travel in a stright line, as long as space is not curved, if its curved then the light itself is curved also. Large bodies with high gravity curve space and this is what causes gravitational lensing, bending the light around it.

      One of the theories is that the universe is a torus. (donut shape, now don't eat it Homer) But this isn't what makes us see it.

      To clear up your confusion, the way I see it is this background of the radaiton is the surface of that intial ba

      • No... for us to be able to see 13 billion year old radiation in all directions, the universe would have to have expanded at several times the speed of light in those first 400,000 years, wouldn't it? And we'd have to be sitting at pretty close to the center of the universe, or light from some directions would be much older than others. To me, this argues for some strange wrap-around condition of the universe, like the toroidal universe that you mentioned.
        • At the time of this radation's "birth" the universe was said to be only as big as either the solar system or the galaxy, so every point in the universe is relativly close to one another, comapred to today. 10^5 verses 10^10, so we could say to see it everywhere we were close to the center of the universe as was every other place. The light from other places of the universe ould only be at most 200,000 years older.

          As to the first part. It is due to the severe redshifted nature of this radation that puts it

          • Also of note the universe is still accelrating which blows my mind.

            One of the theories that is attached to the standard model claims that there is some "inverse gravity" (I'm summarizing A LOT here!) provided by some yet-to-find particles (what could make the dark matter is a good candidate) or forces. More, there are assumptions that gravity is a strong attracting force locally (at short distance), but at the scale of the universe, it would actually be a repulsive force. Talk about mind blowing!

            until I

            • "More, there are assumptions that gravity is a strong attracting force locally (at short distance), but at the scale of the universe, it would actually be a repulsive force. Talk about mind blowing!"

              For what I know, they (I really don't remember the names) actually used a model with gravitational force that was repulsive at huge distances when they tried to build a static model of universe (ie. one which does not collapse back after a couple billion years). Eventually it had to be trashed because it didn't
        • Well... Lets use the old dots on a balloon analogy. When the photon was emitted it was not a "microwave" photon and the entire universe was much much smaller. Space itself expanded tremendously - like the balloon. Now since our "balloon" (universe) expanded farther than our event horizon from the beinning of the universe it doesn't really matter if it is closed (like a balloon) or open (like an infinite sheet of paper) to us it looks open and every place is equally the "center". Also the photon wavelength i

        • Re:This has always confused me (Score:4, Informative)

          by Zaak ( 46001 ) on Friday October 08, 2004 @02:26PM (#10473257) Homepage
          ...the universe would have to have expanded at several times the speed of light in those first 400,000 years...

          Yes. During inflation the universe expanded not at several times the speed of light, but rather doubled its size every 10^-34 of a second. After about a hundred doublings the inflationary period ended and expansion slowed to (locally) sub-light speeds.

          The microwave background didn't come from the big bang though. It was actually emitted from the surface of last scattering when the universe became transparent for the first time--around 300k years after the big bang.

          ...we'd have to be sitting at pretty close to the center of the universe...

          The "center of the universe" is not well-defined. If the universe is topologically closed, then it has neither center nor boundary, like the surface of the earth. If the universe is topologically open, then it is infinite in size and similarly has neither center nor boundary.

          TTFN

          • Pardon me but if the universe expanded in such a manner wouldn't that be against the theory of relativity. What about breaking causality ?
            Perhaps this is a foolish question.
            • It's not a foolish question, but a very subtle and often misunderstood point. It is necessary in cosmology for *coordinate* velocities to exceed that of light. That's ok. What's not ok is for any arbitrary clump of matter to exceed the speed of light getting from one point to another. In reference to the balloon example, it's ok for the balloon to expand as fast as it wants, but we have a speed limit in getting from one dot to another.
              • First, thanks for your explanation.
                If I understand you correctly then you are saying that if there is a particle at some point and the point is moving because of expansion then the particle will not move with the point (or with the same rate)
                • If I understand you correctly then you are saying that if there is a particle at some point and the point is moving because of expansion then the particle will not move with the point (or with the same rate)

                  The particle moves with the point. This causes particles at sufficiently distant locations in the universe to be moving faster than light relative to each other.

                  This is still consistent with relativity. The usual way of explaining this is to say that the particles are standing still, and space itself
                  • Perfectly clear now. This is why the Alcubierre drive can travel faster than light.
                    I thinnk the same princile is behind the fictitious star trek warp drive.
                    • How about this:

                      A ballon can inflate as fast as it likes. Any ants on the surface of that ballon get carried along with that inflation. Relativity says that ants cannot crawl across the surface of the ballon faster than a certain speed.

                      Nothing can move through space faster than light, but when the space itself moves the the stuff in it gets carried along.

                      -
                    • All right. That explains why the causality is not broken. What about the other problem ?

                      Suppose there are two ant then the ant see the other ant moving away with the speed of light. this means the clock in the other ant frame of reference has stopped and the ant has infinite mass.
                    • But how do they see each other? That's the point -- no information, including light, can travel between two coordinates faster than light. Coordinates can separate faster than light, but there is no "connection" between them.
                    • There's a really good explanation if I could make up and show a video, but I'm having trouble puting it into text.

                      Ok, say two ants are right next to each other. Lets call them Alice and Bob. Both are motionless. They each have a clock, and the clocks are sycronized.

                      Not I want to introduce a certain concept of hot you look at a clock. At an instant some light bounces off of the clock. That arrangment is like a photgraph of the clock. It then flies to your eye and you see that photo.

                      Ok, so Alice and Bob ar
                    • Minor quibble:

                      Photons from close to tht horizon are red-shifted, they lose energy. remeber the hot glowing soup from the big bang? It was really really hot, giving off X-rays and gamma rays and everything. However the light we now see from the big bang is from really really far away, almost at the horizon. X-rays with a 1 nanometer wavelength have been getting constantly stretched by space itself over the umpteen billion year journey. They stretched out by a factor of tens of thousands, stretched out into

                    • Thanks for the answer.
                      I am not a physicist so bear with me. The problem with your explanation is that you say when time slows down because the observer SEE it slowing. This is not the case, the time actually slows down. you can make correction for the speed of light still you will see the clock slowing down.

                      Consider my example. Alice is travelling in a train and Bob is in the platform. On the train floor is a light source which sends a beam straight up the ceiling. On the ceiling is a mirror which reflects
                    • Consider my example. Alice is travelling in a train and Bob is in the platform.

                      Your example has Alice actually traveling through space. Remember I specifically pointed out that both Alice and Bob are each motionless, so from that viewpoint their clocks will run at the same rate. From other viewpoints the ordinary notion of time gets shot all to hell.

                      Traveling through space and being carried along by expanding space look much the same, but in some cases they have some different implications. For example n
                    • All right. Consdier Alice and Bob are being carried along by expanding space but they are motionless themselves. Also, assume that the rate of expansion is less than the speed of light.
                      Q1. Will Alice actually see Bob clock slowing down ?
                      Ans: Yes.
                      Not see as in it takes some amount of time for the light to reach Alice but see as it in Alice adjust the time by taking that time in account. For example if Alice sees that the Bob clock is 1200 hrs and Bob at that time is 1 light hour away then Alice will assume
                    • I think the problem is in using the word "actual", and I think it easiest to explain if I go back to your previous post and that train example.

                      Alice is travelling in a train and Bob is in the platform. etc etc etc...

                      Ok, you explain how Bob see's Alice's clock appears to run slower. The problem is that you are thinking that Alice's clock is actually running slower. It is not. That may sound wrong, but bear with me a second.

                      Instead of looking at it from Bob's point of view lets ride along with Alice. We l
                    • First of all, I understood you loud and clear. Your explanation was lucid but I have to respectfully disagree with your explanation.

                      I also cheated here, because what I explained was not my explanation. You can read it from
                      http://www.physicsguy.com/ftl/html/FTL_part1.html/ [physicsguy.com]. The article explains that how the time slows down.

                      I am not a physicist so all my understanding comes about the relativity comes from this article.

                      My orginal question was how come the universe can expand at the rate which is faste
                    • http://www.physicsguy.com/ftl/html/FTL_part1.html The article explains that how the time slows down

                      Your own link says time (clock) does *not* slow down:

                      Now, don't be fooled! One of the first concepts which can get into the mind of a newcomer to relativity involves a statement like, "if you are moving, your clock slows down." However, the question of which clock is really running slowly (yours or mine) has no absolute answer! ... In my frame of reference your clock is running slower than mine, but in you
                    • You are getting me wrong. The clock actually slows down its not that it appears that the clock is slowing down. What the paragraph you quoted is saying that both the frame of reference are correct. IF I understand you correctly you are saying is that if this is the case then what happens when both Alice and Bob meet again. This is twin paradox and has been explained.

                      Also, if I accept you reasoning then if Alice and Bob are moving toward each other the clock will go faster for Bob in Alice frame of refern

            • Re:This has always confused me (Score:4, Informative)

              by Zaak ( 46001 ) on Friday October 08, 2004 @02:56PM (#10473603) Homepage
              Pardon me but if the universe expanded in such a manner wouldn't that be against the theory of relativity. What about breaking causality?

              Well IANAP, but I'll explain what I understand of it.

              Relativity requires that no signal can travel faster than the speed of light. During inflation, nearby parts of the universe move away from each other faster than the speed of light. However, because there is no signal traveling FTL, causality is not violated.

              TTFN
          • The microwave background didn't come from the big bang though. It was actually emitted from the surface of last scattering when the universe became transparent for the first time--around 300k years after the big bang.

            Exactly... Just to make the point more clear, the "surface" of last scattering is really a point in time - the photons that were released at the time of the last scattering (last interaction with matter, when it changed from opaque to optically thin) filled the entire universe at that time. T
          • Again, the fact that we see the same levels of microwave radiation in all directions pretty much argues for a topologically closed universe, doesn't it? For it to be topologically open, you'd have to throw out the big bang theory that the universe originated at a single point. Either that, or just all the mass/energy originated at a single point, and we're still closer to that point than most of the mass/energy out there. Yes, you've pretty much convinced me that 1) the universe is topologically closed and

            • For it to be topologically open, you'd have to throw out the big bang theory that the universe originated at a single point.

              According to Big Bang theory, if you extrapolate back toward t=0, all objects get closer and closer together. That's not really the same as "originating at a point", which seems to imply that it started at a specific physical location. The origin is a singularity, in the sense that the density rises to infinity and distances between any two objects gets asymptotically smaller, but it c

    • In which case, shouldn't any radiation created by the big bang be at least 13 billion light years away from it's point of origin by now?

      Yes. Except that all points expanded at a rather amazing speed away from the point of origin. The microwave radition we're getting now is the radition from points that are about 13 billion light years away "now", along the path the radiation took.

      Since we only have a 13-billion light year radius bubble of information, we can only conjecture as to what shape the univers
      • Wouldn't the source of the radiation have to be 13 billion light years away "then" (at the time it was radiated) 13 billion years ago), not 13 billion light years away "now"? Well, okay, that's not entirely true. If we have been moving away from the point of origin at say, half the speed of light, then the source would only have to be 6.5 billion light years away when it was radiated. Or less distance if we have been moving even faster. But then I still wouldn't expect a uniform distribution of radiation in
        • The answer in layman's terms I think is: yes, the universe expanded faster than light, which is why we still see light from the big bang - it didn't all "whoosh" past us.

        • Re:This has always confused me (Score:1, Informative)

          by Anonymous Coward
          There is no point of origin (in the usual three dimensions, anyway). The universe expands equally in all directions. That's why it looks like everything is moving away.

          All points were the point of origin, because there was only one point to start with. Only later did the universe get big enough that you could distinguish point A from point B by the distance between them -- but then both points have an equal claim to having been "the original point of origin".

          The reason scientists are so keen on the exa

    • Don't microwaves move in a straigth line?

      Yes (well, technically it doesn't in a curved space-time, but since the universe is globally flat, any deviations are extremely small on average).

      In which case, shouldn't any radiation created by the big bang be at least 13 billion light years away from it's point of origin by now?

      Yes.

      So, unless they are reflecting off something or the universe wraps around at the edges, why can we still detect them?

      Uh... here's where you've lost me. They're going in straight lin

      • Um, this particular aspect of the BBT has bothered me for awhile too. Presumably the universe and the matter in it could not expand more rapidly than light. Which means, one would suspect, that any radiation from the BB would be "ahead" of us traveling along the leading "edge" of the "inflation front" fron of the universe.

        Now if you want to say that this means the universe is closed, I can see that, but would that not also mean that any radiation we see from "near the beginning" would have to be not less

        • Presumably the universe and the matter in it could not expand more rapidly than light.

          Those two statements are different... matter cannot move faster than the speed of light, but the expansion of the universe can.

          In fact, the expansion of the universe doesn't have a physical velocity associated with it - it's a fractional rate of change. So if the universe expands at "0.1 Gyr^-1", then proper distances increase by 10% per gigayear (*). If the distance you're interested in is larger than 10 billion light ye

          • Oooo-kay, this may be why I went into archaeology.

            Hubble's constant is a ratio scale measure, the "speed" is protportionate to the distance being discussed. I remember that much from college physics. Now, I also remember George Gamow, in one of his books via a raisin bread analogy, explaining the red shift limit as a function of the expansion of the universe, and saying more or less that the apparent speed that remote bodies are receding is due to the cumulative expansion of the space in between. The fa

            • If I understood what you wrote though, it seemed that you are suggesting that the relative rate of separation between two remote bodies can be greater than SOL (e.g. the most separated of Gamow's "raisins"), but the article is implying that we can see almost all the way back to the BB.

              Ah, but remember that the distance between the two objects is getting larger. Which means that the red shift has been getting larger with time. If we see a photon from an object that's currently moving away from us at the spee

              • Zeno would have loved that discourse. You still have me wondering about the relativity of relativity so to speak. Partly of course, I asked a question that more or less begs for an interpretation of a "simulataneous" state between to very remote objects, which Einstein I think described as a nonsensical concern. Still, in this universe, can two objects have relative speeds that are greater than the speed of light? I guess my problem is that I more or less got the idea that the the BB involved an object

                • Zeno would have loved that discourse.

                  Heheh... I purposely avoided using calculus to make sure I didn't lose anyone. :-)=

                  Yes, it's quite possible for two objects to have relative speeds that are greater than the speed of light. What I think you're getting at is that photons that are currently emitted from an object that is currently moving away from us at greater than the speed of light will never reach us. But we can see photons that were emitted from these objects in the past.

                  I guess my problem is that

    • Re:This has always confused me (Score:5, Insightful)

      by Alsee ( 515537 ) on Friday October 08, 2004 @07:33PM (#10476120) Homepage
      Several others have tried to answer, but I don't think you got any clear and correct answer.

      The thing that is confusing you is that you have the very common image of the big bang being like a hand grenade explosion in the vacuum of space. You are picturing there is some point in the middle of our universe that was the center, from which everything spread out. The big bang is is no normal explosion, it was an explosion of space not in space, and there is no center in our universe.

      In order to explain a picture of what it *is* like we need to imaging the universe is 2D instead of 3D. Imagine we live in a 2D sheet of rubber rather than 3D space. Now lets curve that sheet of rubber around into a ballon. We live in the surface of that ballon. There is *nothing* inside or outside the skin of the ballon - not even a vacuum. Our universe *is* the skin. You, me, the sun, the stars, they are specs within that skin.

      That ballon is expanding. In the past the was smaller. Imagine running backwards, srhinking that ballon down to a point. That point would be the big bang. It was in the past, sort of in the center of our current ballon. That point is not anywhere in our universe, it is not on the skin of the ballon.

      Now to explain the microwaves we see from the big bang. When you run backwards all of the stars and dust and gas were closer together in the skin of that smaller ballon. Go back far enough and everything in our universe was squashed togther - everywhere. There was very little space itself for it all to fit in. All of the space in our universe was filled with a dense hot soup of glowing particles.

      So that glow came from everywhere in our universe. No matter what direction we look, that point umpteen billion light years away was glowing umpteen billion years ago. The very spot we are at now was glowing umpteen billion years ago, and if someone billions of light years from here were to look at us they would see that old glow from here.

      Did that make sense?

      -
    • Everyone makes this mistake at first. You're thinking of an infinite expanse of empty space, and at some point there's a colossal explosion, from which there is now a Universe expanding outwards.

      Wrong.

      If that was the case, then the Universe of matter would form an expanding spherical shell with the detonation point at the centre. What would we observe? Answer: galaxies all aligned in one plane as we look tangentially along the sphere, complete void in the outward direction, and maybe a very faint glow f

  • More information (Score:4, Informative)

    by TMB ( 70166 ) on Friday October 08, 2004 @12:43PM (#10471842)
    The press release at the CBI website [caltech.edu] is much more informative.

    The big news is that they've measured the polarized power spectrum, and it agrees extremely well with the theoretical predictions. Which means that not only do the density fluctuations match what's expected, but the matter is moving in the gravitational field of those density fluctuations exactly as expected.

    [TMB]
  • Basically an updated recipe for a pancake of extreme proportions; we now know whether there should be lumpy bits or not.
  • They never say how fast or dont know, but is it possible in theory that the expansion was faster than light?
    • any part of the original expansion faster than the speed of light would be forever inaccessible to us - couldn't see it or reach it, by current theory.

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