Posted by Southern Man on Jun 10, 2002 at 08:28
(209.102.128.195)
Re: Universe is only seven days old (DA Morgan)
You seem to have taken a lack of knowledge as a statement of fact. Since the following is the only mention of a center in the link you provided, I have to assume you are referring to:
"Here's a subtle point that you may have wondered about: If we look out into the Universe and every galaxy we see is moving away from us, doesn't that mean that we are at the center of the Universe? The obvious answer seems to be 'yes', but actually the answer is 'no'. Hopefully the following analogy will explain why. Image a loaf of raisin bread baking in the oven. As the bread bakes it gets bigger, and every raisin moves away from every other raisin. Now imagine that you are sitting on one of the raisins (ignore the heat of the oven). All the other raisins are moving away from you, so you might conclude that you are at the center of the loaf of bread. But if you were on a different raisin you would also see every raisin moving away from you and would also conclude that you are at the center of the loaf. The same thing is happening in the Universe. No matter where you are in the Universe, every galaxy you see is moving away from you. That's why astrophysicists say that you shouldn't talk about the center of the Universe; there really is no center of the Universe."
Does this mean there is no center? No, it just means that you can't look at the stars to find it. Einstein had a far more rigorous proof of no center but he also was looking at the current state and showing that a different center exists for each different reference frame. A more complete article can be found at http://itss.raytheon.com/cafe/cosm/bang.html Does that mean there is no center in the reference frame of all space? No, it just means that we can’t look at individual pieces and find it. But what if we could look at all space at once? Just as we can look at the crust of our loaf of raisin bread (from inside our outside) and so determine a center, if we could look at the expanding surface of space we could determine a center. Until recently that seemed impossible. But then in 1965 we saw something that is very very close to the edge of space. The Cosmic Microwave Background radiation comes from the space at the edge of all space. And guess what – it is different in different directions just as a particular raisin would see the crust being different distances in different directions. In the late 80’s we obtained the data that proves that we aren’t at the center of the universe. The CMB shows that we are moving at a very high speed with respect to the CMB toward the Virgo Supercluster. http://www.physics.ucsb.edu/~jatila/cmb_linked.html
So even though it seemed impossible for a time to determine where the center was (and so some people simplified this by claiming there was no center), we now know that not only does the center exist (which only makes sense) but we finally have a way of determining where it is.
P.S. I certainly hope that you don't teach a subject that needs any science background. Political science might be your forte.
the universe is ~6kyo anyman 12/6 04:12
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