Do you know anything about cosmology?
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Physical cosmology is the branch of physics and astrophysics that deals with the study of the physical origins of the Universe (the Cosmos) and the nature of the Universe on its very largest scales.
1089963
Of course, it's difficult to say. The understanding of the cosmos is full of extraordinary ideas and insights. I'd tend to mention Copernico, who first stepped on the modern view of the Universe putting the Earth moving around the sun. And then Kepler, who gave the three fundamental laws of planetary movement, based on the extremely accurate and extensive data collected by Tycho Brahe WITHOUT a telescope.  And of course, Einstein. His General Relativity Theory is the cornerstone of the current cosmology.
18930
There have been alternative theories throughout history.  I believe most astronomers now accept the Big Bang theory as best fitting the known facts. Your question about a multiplicity of Big Bangfs is a good one: perhaps the biggest cosmological debate about the nature of the universe is whether the universe will expand forever, or whether it will ultimately contract again into a state similar to just prior to the Big Bang.  Of those who think it will contract, many believe that it then will repeat a Big Bang process, so that the universe will proceed on a Bang, expansion, contraction, Bang  . . . pattern forever.\n\nI've included a link to one website that provides answers to basic astronomical questions, in a range from beginning to more advanced.
31705
The best guess today: no.\n\nIn modern cosmology the topology of the universe appears to be open. "Topology" meaning the shape, although in the case of the universe to observe the shape we would have to exist in 4 spatial dimensions. Since we're stuck in 3-dimensions we have to get by on analogies.\n\nThe topology or shape of the universe is something which comes out of Einstein's General Theory of Relativity. It depends primarily on the distribution of mass and energy in the universe. If the amount of mass-energy is more than a certain critical value then the universe would be "closed." Basically the mass would curve space-time back onto itself. In a closed universe you could fly off in the direction of the north pole and (after about 25 billion years) and circle the universe to land on the south pole.\n\nIf the amount of mass in the universe is less than this critical value then the topology of the universe is a bit more complex, but, to answer your question space would be infinite.\n\nBased on what we know today that is the case, space is infinite.\n\nHowever, we cannot see an infinite universe. When we see things that are farther away we also see them from deeped in the past. A galaxy we see that is 10 billion light years distant is actually a view of what the galaxy looked like 10 billion years in the past.\n\nWhen we look farther in space, and thus earlier in the history of the universe, we eventually run into the microwave background. For the first 10,000 years or so after the Big Bang the universe was so dense that it wasn't yet transparent. When the density dropped enough to be transparent then some of the light could escape for us to detect much later.\n\nHowever, while the universe is thought to be about 13 billion years old, we can actually see out a bit farther than that, I think around 20 billion light years, because the universe is expanding.\n\nWhat this boils down to is that there is a sort of "wall" beyond which we can't see. This wall corresponds to a time soon after the Big Bang. However, studies of the total mass-energy within the universe strongly suggest that it has an open topology - that it is infinite.\n\n(Of course it is possible that this infinity will be refined when we have a better theory of how Quantum Mechanics and General Relativity play togther. String Theory is one way to combine these two.)
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Big Bang is a theory that tries to explain the formation of the universe, its galaxies, its stars and planets etc.\n\nIt says that the Universe was created by an explosion of a Primeval Atom thus causing it to expand and move away from each other. This was actually based on the Hubble Law which says that Galaxies around us are expanding at speeds directly proportional to their distance from Earth, based on the observation of Edwin Hubble, 1929.\n\nIts a huge topic with lots of technical arguments and counter arguments. Here is the link that will satisfy your quest on Big Bang, atleast for starters...\n\n.:Fishie:.
722171
......you dont know squat about anything involving science, do you?
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Sorry to be me, but someone has to tell you: you think as a person from the Middle Age, that is, half a millennium ago.\n\nThere was some progress since then.\n\nThere is no heaven and no vault to go beyond, in astronomy. We are on a planet orbiting around a star which is located in a galaxy, which is part of a huge galactic conglomerate, in a multidimensional expanding universe, geometrically described by the General Relativity, for which the very concept of "border" or "vault" would be ill-posed anyway.\n\nSorry, the reference framework for cosmology is Astrophysics, not the Divine Comedy.
47001
Other pages in this Astrophysics/Cosmology section are: \n\nGravitational Entropy (June '98) \nA Debate on Open Inflation (November '98). The lecture is saved as a postscript document. \nQuantum Cosmology, M-theory and the Anthropic Principle (January '99). \nRotation, Nut Charge and Anti de Sitter Space (February '99). \nLinks \n\nHome \n--------------------------------------------------------------------------------\n\nPhysics Colloquiums - Inflation: An Open and Shut Case (April '98).\nSlides and audio for this talk can be downloaded from the ITP at UCSB.\n\nThis talk will be based on joint work with Neil Turok, at Cambridge. Neil has always been interested in what might be called, alternative cosmology. He pushed the idea that topological defects like cosmic strings or textures, were the origin of the large scale structure of the universe. And he was a proponent of what is called, open inflation. This is the idea that the universe is infinitely large, and of low density, despite having been through a period of exponential expansion, in the very early stages. My opinion was, that these were all nice ideas, but that nature probably hadn't chosen the use any of them. I included open inflation in that list, because I believed strongly that the universe came into being, at a finite size, and I felt that implied that the universe now, was still of finite size, or closed. However, after Neil gave a seminar on open inflation in Cambridge, we got talking. We realized it was possible for the universe to come into existence, at a finite size, but nevertheless, be either a finite, or an infinitely large universe now. My talk will be about this idea, and new developments that have occur since then. One of these, which is so recent that it is not yet fully worked out, is that it seems there is an observational signature, of the kind of inflation Neil and I are proposing. The present measurements are not sensitive enough to see this effect, but it should be possible to test for it, in the observations the Planck satellite will make.\n\nAnother recent development, is that observations of supernovas, have suggested that the universe may have a small cosmological constant, at the present time. Even before these observations, Neil and I had realized that if there was a four form gauge field, one could invoke anthropic arguments to make it cancel the cosmological constant, that one would expect from symmetry breaking. But the anthropic argument would not require it to cancel exactly. So there could be a small residual cosmological constant. This is exciting. I shall describe the observational evidence later.\n\nAs you probably know, the universe is remarkably isotropic on a large scale. That is to say, it looks the same in all directions, if one goes beyond such local irregularities as the Milky Way, and the Local Group of galaxies. By far the most accurate measurement of the isotropy of the universe, is the faint background of microwave radiation, first discovered in 1965. At the present time at least, the universe is transparant to microwaves, in directions out of the plane of our galaxy. Thus the microwave background, must have propagated to us, from distances of the order of the Hubble radius, or greater. It should therefore give a sensitive measurement, of any anisotropy in the universe.\n\nThe remarkable fact is, that the microwave background is the same in every direction, to a high degree of accuracy. It wasn't until 1982, that differences between different directions were detected, at the level of one part in a thousand, with a dipole pattern on the sky. However, this could be interpreted as a consequence of our galaxy's motion through the universe, which blue shifted the microwave radiation in one direction, and red shifted it in the opposite direction. It need not represent any intrinsic anisotropy in the universe.\n\nIt was not until 1992, that tiny fluctuations on angular scales of 10 degrees, were
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I believe the universe is part of something much bigger.  There are many unknowns and anomalies that scientist having problems with.  Galaxies moving in and others move out.  Blue stars beyond the known universe.  \n\nThe bible says that the universe is a tent for God to dwell in.  That indicates certain things.  It is inside something, and is a temporary shelter.  It also says that in certain areas are chambers.  \n\nThere is much yet to discover.
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I am certain you have heard of the Big Bang if you can articulate the question as lucidly as you have.  See this month's Scientific American for an excellent article that delves into the latest expierimental evidence in support of current theories that take us back to the first millisecond of the universe.  This article is featured on the cover.  If you can't get your hands on it, send me an email to strangerbarry@yahoo.com and I'll scan / email it for you.
313404
It could be possible but there is something called the cosmological principle that are a set of assumptions about the universe that prevents us from determining that.  Basically we need to assume, among other things, that the laws of physics, as they apply here, work the same in other parts of the universe.  Without this assumption we couldn't make any statements about the universe since it would be pure speculation.
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We cannot say.\n\nAt the moment we only have information from when the big bang happened to like 1 billionth of a second.\n\nWe do not know what was before the Big Bang as the universe is time and space and everything. Anything before there has a negative time which is impossible..
484105
Yes I do. Think of how big we can honestly say we know that space is, then think a million times that size. There are probably millions of different universes out there.
26538
Surely you know the proponants do not have an answer. On the same note, neither can anyone answer (yet) what was there before Big Bang?
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Laney, first of all allow me to say that I'm incredibly glad and pleasantly surprised to hear of your genuine interest in this field.   You are to be truly commended for your intellectual courage and abilities.  ...But to address your question, there are in fact thousands of great explanatory/layman-type books out there on Quantum Mechanics, Field Theory, Gravity, Philosophy, Reality, and associated topics like cosmology, etc.  Some of them even dating back to the mid 70's, that nonetheless are still wonderful reads.  ...Theoretical physics at the level that we are talking about here, though, is unfortunately a seven-headed exotic mathematical monster that is not even accessible to most physicists, much less the lay person.   Having said that, and as you know, there have been courageous attempts by talented physicist like Brain Greene (and many others before and after him) to make our latest theoretical/scientific visions of the physical world/universe available to the general public.   ...Since you mentioned that you are NOT mathematically inclined, but did enjoy Greene's The Elegant Universe, the first thing that came to my mind (and the book that I would recommend most) was in fact Greene's newer work called "The Fabric of the Cosmos: Space, Time, and the Texture of Reality" - in case you haven't read it yet.    \n\nAmong some of the other more recent titles worth mentioning also are:\n\nThe Great Beyond - by: Paul Halpener (A very nice book)\n\nThe Cosmic Landscape - by: Leonard Susskind\n\nHiding in the Mirror - by: Lawrence M. Krauss\n\nThe Road to Reality - by: Rofer Penrose\n\nA First Course in String Theory - by: Barton Zwiebach (This is a very nice book but a lil' more mathematically oriented than you might enjoy - let's say undergraduate physics level) \n\nI also highly recommend:  The Five Ages of the Universe - by: Fred Adams\n\nThat should keep you busy for a while - Good Reading!  ;-)
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I don't know what cosologists are hypothesizing about.  Cosmologists on the other hand, are hypothesizing that the universe is expanding.
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The short answers are:\n\nNobody really knows,\n\nand,\n\nYes, it's possible the universe is collapsing.\n\nIn fact, it's amazing how little we really "know" about the universe.\n\nOf course that just encourages people to propose more theories.  After all, to get a Phd you only have to write a thesis, you don't have to prove it!  Yes, you have to "defend" it, but that's not the same as proof.\n\n"The Big-Bang", "String Theory" (proposed to prevent the Big-Bang from collapsing) and "Steady-state Universe" are all conjectures based on imagination.  So far, there is only contradictory evidence to support any of these theories. We'll have to await the next Einstein to sort it all out!\n\nBy the way, what has Hawking contributed to cosmology?  I've read his stuff, and all he does is elaborate on other's thinking.  Just like Carl Sagan.  I think both are overrated and unoriginal. \n\nWhat do you think?