The Holy Mol Posted December 20, 2004 Posted December 20, 2004 Providing there is an edge and that the universe is expanding, I wonder if it can be detected. We are seeing objects pretty far out there. We are seeing so far back that we're seeing more towards what the beginning looked like...new stars and such. Well, what happens when you're looking so far that the stars haven't formed yet? No energy is being made! How do you detect just dust and gas on the far side of stars? Energy from stars isn't passing through the dust on the way to us thereby transfering energy to the dust and making it visible. Therefore I conclude that we will never see the edge of the universe, not in a million years or it comes crashing back in on us. Discuss. <Sips hot tea>
psi20 Posted December 20, 2004 Posted December 20, 2004 Speaking of which, where's the edge of the earth?
Ophiolite Posted December 20, 2004 Posted December 20, 2004 It doesn't have an edge. It doesn't have a centre.
2004einstein Posted December 20, 2004 Posted December 20, 2004 In the multiverse theory isn't there a membrane seperating the multiple universes?. As for being able to define an edge even then I would have thought there would be some kind of perpetual space law prohibiting this, but who knows the irrefutable answer?.
Sayonara Posted December 20, 2004 Posted December 20, 2004 I seriously doubt that such a membrane is envisioned as being a part of our three dimensional view of things.
The Holy Mol Posted December 21, 2004 Author Posted December 21, 2004 Speaking of which, where's the edge of the earth? Yes, I have heard that if you have a fast camera you can snap pictures of it right before you fall off! Hmm, how about seeing the outer diameter instead of the edge? If the universe started from a single point and grew (in whatever way, bing bang, miracle grow or whatever) there must be a finite distance from that point. How do you detect that outer diameter without actually travelling there (assuming that we have not already crossed boundries with another universe or universes (universi? Universities?! ))? Is the universe 2d or 3d round? Discuss. <Sips hot chocolate>
The Holy Mol Posted December 21, 2004 Author Posted December 21, 2004 It doesn't have an edge. It doesn't have a centre. I don't understand how it cannot have an edge nor center. It could surely have a sort of average center even it the universe was not completely round.
Ophiolite Posted December 21, 2004 Posted December 21, 2004 If I understood everything I post I would be making a fortune writing popular science books. Fortunately some people do - understand what I post - even when they haven't read it. Here is one of them: http://math.ucr.edu/home/baez/physics/Relativity/GR/centre.html Hope that helps.
Guest cincirob Posted December 21, 2004 Posted December 21, 2004 The comment that the universe has no center and no edge has not been proven. The mathematics that cosmologists use assume that case. As long as the universe is at least very large, the math probably works OK. Based on the Hubble constant, there is a cosmolgical horizon that is receding from us at the speed of light. We cannot recieve information from anything beyond that horizon and it is getting farther away all the time. That distance is almost 14 billion light years away. If this number sounds familiar, it's because 14,000,000,000 years is the age of the universe. As for the center and the edge, you can read that the universe was once the size of a beach ball. When you read that it means the size of the visible universe...the 14 billion ly radius out to the cosmological horizon was the size of a beach ball. We currently don't know how much bigger it was. If it all started out as a singularity, then it's hard to imagine that singularity is infinite. So around in circles we go. On thing though, if not having an edge means it's infinite, then it probably has an edge. There are reasons to believe it isn't infinite.
Ophiolite Posted December 21, 2004 Posted December 21, 2004 If it all started out as a singularity, then it's hard to imagine that singularity is infinite. Everything about singularities is hard to imagine. That doesn't mean they lack properties.
Tesseract Posted December 21, 2004 Posted December 21, 2004 Edge? I thought the universe was sphereical? you mean like a boundry or an intersection. If its a boundry then it must be still growing so it cant exist because theres nothing there yet.
The Holy Mol Posted December 22, 2004 Author Posted December 22, 2004 Ophiolite, that helped a little bit but I did not find it to support the theory of no center to the universe. Because I do not have the mathematical skills to comprehend how there could not be a center my common sense will tell me it does exist*. Why are galaxies accelerating from each other? Not just maintaining a constant velocity moving away from each other but the velocity is increasing. The Hubble Constant seems a little misleading since I didn't read anything that said there was a constant and that the value has to be reevaluated periodically. *Unless the universe is infinite...which (to me) would discredit the big bag theory...because if an infinite sized universe exploded from an infinitely dense object then the object would be of infinite size...right? Or is the infinite applied to space while the matter in space is finite? Ho hum, all out of drinks today
alt_f13 Posted December 23, 2004 Posted December 23, 2004 http://news.bbc.co.uk/2/hi/science/nature/1345134.stm We've seen back 12 Billion years eh? Nifty.
Bettina Posted December 23, 2004 Posted December 23, 2004 How did they come up with the idea of membranes. Is it something that someone dreamed about? I just dont get this at all. Bettina
aguy2 Posted December 24, 2004 Posted December 24, 2004 How did they come up with the idea of membranes. Is it something that someone dreamed about? I just dont get this at all. Bettina We don't have the instrumentation to have any observational or experimental knowledge to determine if such small things exist or not. I don't want to seem to be belittling the valuable work the various 'string' theorists are doing, but what they have been doing is more akin to philosophical spectulation (dreaming) than it is to verifiable physics. Merry Xmas. aguy2
alt_f13 Posted December 25, 2004 Posted December 25, 2004 I think she was talking about the big ones, Brah... the universe sized ones, which we may reside on. They came up with the idea of 'branes through String theory. They probably arrived at it after discovering that the tiny ones aguy2 was talking about were probably the solution to fitting six extra dimensions in to our three dimensional world. The six extra dimensions were needed mathematically for string theory to work. I know that makes little sense, but watch the show in this link and read it again... http://www.pbs.org/wgbh/nova/elegant/program.html
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