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Motion of the Primordial Universe Revealed
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."
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 ball of matter of the universe. We exsist within that ball. The light that was given off 13.7 billion years was in the visable wave lengths, but since it was expanding away from us, this light was red shifted all the way down into the microwave range.
So this microwave light we are percieving, is the light being emmited by the matter shell of the early universe at the time of the early universe. Its only taken this long because the shell was moving away from us.
Clear as Mud?
The press release at the CBI website 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]
As to the first part. It is due to the severe redshifted nature of this radation that puts it so old and able to be so old. Its one of the wierd poperties of light. At least the accepted theory states.
Also of note the universe is still accelrating which blows my mind.
I like to do math and when trying to comeup with numbers to go through (which i haven't yet) i found a good explnation here.
This type of confusion is common I believe when dealing with non mechical physics. Relies on fundementals elsewhere that the eggheads can't explain in even a 10 minute sound bite to us laymen.
I've had similar confusion with the idea of the light barrier, not even my college physics teachers could straighten out until I read Brian Greene's "Ellegant Universe"
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.
It's 10 PM. Do you know if you're un-American?
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.
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
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.
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
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 is moving. I'm not sure that explanation is really meaningful, but it's handy as an introduction.
The upshot of relativity is that you only get FTL relative motion through movement of space itself (corresponding to certain types of curved spacetime), and that once something is moving FTL relative to you, you aren't going to see it again (it's fallen down a black hole or is past an expanding universe's horizon of observable space). Certain even more exotic geometries of spacetime let you see these things again, but it's an open question whether or not this can actually happen (these are the kinds of geometries you use for time travel).
If space is not deformed - i.e., you have flat space, with no extremely large masses - then you aren't able to cause particles to move FTL relative to you, no matter what reference frame you're observing from.
I hope this clears things up a bit.
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 exact pattern of granularity in the almost-but-not-quite uniform microwave background is that such information reveals regions that could have remained in contact and thus narrows down how inflationary scenarios could or couldn't have happened.