Zarnaxus Posted March 10, 2011 Share Posted March 10, 2011 I have gotten into an argument with one of my friends with the size of the universe. Pretty silly argument if you ask me, but nevertheless, i am interested in what your opinions/knowledge on the subject is. Here we are: The universe is huge. Can it be infinite? Where are the boundaries? My point: According to general relativity, space can expand at faster than light speeds, which includes infinity. If the space between two points expands at an infinite rate, the universe can be infinite. I am stating that the universe COULD possibly be infinite. I don't know, I thought that relativity had something to do with expansion of the universe, and it possibly being infinite. His point: The universe is finite.... we have found the boundary already....???......there is no possible way for it to be infinite. If it was, it would have to be infinitely old? If it was infinitely old, the temperature would be the same everywhere, which is not the case. So, the ultimate question is, can the distance between two peices of matter farthest apart in the universe be infinite or not? Link to comment Share on other sites More sharing options...
lemur Posted March 10, 2011 Share Posted March 10, 2011 Nothing definable can be infinite in a representational sense. However, considering that nothing can exceed the speed of light, perhaps the region of the universe defined by the reach of light is in a sense infinite in that anything, including light, can travel infinitely and never reach beyond it. If there is something beyond infinite spacetime, does that make infinite spacetime finite? Link to comment Share on other sites More sharing options...
steevey Posted March 10, 2011 Share Posted March 10, 2011 (edited) I have gotten into an argument with one of my friends with the size of the universe. Pretty silly argument if you ask me, but nevertheless, i am interested in what your opinions/knowledge on the subject is. Here we are: The universe is huge. Can it be infinite? Where are the boundaries? My point: According to general relativity, space can expand at faster than light speeds, which includes infinity. If the space between two points expands at an infinite rate, the universe can be infinite. I am stating that the universe COULD possibly be infinite. I don't know, I thought that relativity had something to do with expansion of the universe, and it possibly being infinite. His point: The universe is finite.... we have found the boundary already....???......there is no possible way for it to be infinite. If it was, it would have to be infinitely old? If it was infinitely old, the temperature would be the same everywhere, which is not the case. So, the ultimate question is, can the distance between two peices of matter farthest apart in the universe be infinite or not? There are no observed boundaries for the universe. Also, as far as scientific consensus is concerned, the universe also has no observed center, even though the universe is said to exist in denser and hotter states previously in time. As far as I see it though, I don't see how the universe couldn't be infinite. Why would space itself, something not proven or disproven to exist, wouldn't go on infinitely, or why there wouldn't be infinite room for matter to expand into. What would be stopping the existence of infinite space? There's also something else too, since the fabric of space itself is not proven to exist, even though the universe is said to be filled with virtual particles, there could still be space of nothingness between those, which if thats the case and true space is nothing, there could be infinite "nothing", since there would be no amount of something to run out of, and there wouldn't be a "something" that needs to travel distances. Edited March 10, 2011 by steevey Link to comment Share on other sites More sharing options...
DrRocket Posted March 10, 2011 Share Posted March 10, 2011 (edited) I have gotten into an argument with one of my friends with the size of the universe. Pretty silly argument if you ask me, but nevertheless, i am interested in what your opinions/knowledge on the subject is. Here we are: The universe is huge. Can it be infinite? Where are the boundaries? In general relativity spacetime is a 4-dimensional Lorentzian manifold. Under the assumptions of homogeneity and isotropy it can be decomposed as a one-parameter foliation of space-like 3-dimensional hypersurfaces (aka "slices"), without boundary. Those slices are spaces of constant curvature and are what is called "space" in cosmology. Homogeneous and globally isotropic spaces of constant curvature are of one of three types: the zero curvature case -- Euclidean 3-space, the positive curvature case -- the 3-sphere, and the negative curvature case -- hyperbolic space. Only the 3-sphere is compact, aka "finite". It is not known which, if any, case represents the physical universe. My point: According to general relativity, space can expand at faster than light speeds, which includes infinity. If the space between two points expands at an infinite rate, the universe can be infinite. I am stating that the universe COULD possibly be infinite. I don't know, I thought that relativity had something to do with expansion of the universe, and it possibly being infinite. An infinite expansion rate is not allowed by general relativity. His point: The universe is finite.... we have found the boundary already....???......there is no possible way for it to be infinite. If it was, it would have to be infinitely old? If it was infinitely old, the temperature would be the same everywhere, which is not the case. There is no boundary. The universe could be finite. It is not infinitely old. In the homogeneous, large-scale approximation the temperature is uniform. The universe is neither homogeneous nor isotropic except as an approximation on the largest scales. So, the ultimate question is, can the distance between two peices of matter farthest apart in the universe be infinite or not? No. Edited March 10, 2011 by DrRocket Link to comment Share on other sites More sharing options...
Spyman Posted March 10, 2011 Share Posted March 10, 2011 I have gotten into an argument with one of my friends with the size of the universe. Pretty silly argument if you ask me, but nevertheless, i am interested in what your opinions/knowledge on the subject is. Here we are: The universe is huge. Can it be infinite? Where are the boundaries? My point: According to general relativity, space can expand at faster than light speeds, which includes infinity. If the space between two points expands at an infinite rate, the universe can be infinite. I am stating that the universe COULD possibly be infinite. I don't know, I thought that relativity had something to do with expansion of the universe, and it possibly being infinite. His point: The universe is finite.... we have found the boundary already....???......there is no possible way for it to be infinite. If it was, it would have to be infinitely old? If it was infinitely old, the temperature would be the same everywhere, which is not the case. So, the ultimate question is, can the distance between two peices of matter farthest apart in the universe be infinite or not? I think Wikipedia reflects the scientific consensus rather well and therefore can be considered evidence of what is generally agreed upon by professional scientists in the area. "The universe is immensely large and possibly infinite in volume. The region visible from Earth (the observable universe) is a sphere with a radius of about 46 billion light years, based on where the expansion of space has taken the most distant objects observed." http://en.wikipedia.org/wiki/Universe "The diameter of the observable universe is estimated to be about 28 billion parsecs (93 billion light-years), putting the edge of the observable universe at about 46-47 billion light-years away." http://en.wikipedia.org/wiki/Observable_universe "Both popular and professional research articles in cosmology often use the term "universe" to mean "observable universe". This can be justified on the grounds that we can never know anything by direct experimentation about any part of the universe that is causally disconnected from us, although many credible theories require a total universe much larger than the observable universe. No evidence exists to suggest that the boundary of the observable universe constitutes a boundary on the universe as a whole, nor do any of the mainstream cosmological models propose that the universe has any physical boundary in the first place, though some models propose it could be finite but unbounded, like a higher-dimensional analogue of the 2D surface of a sphere which is finite in area but has no edge. It is plausible that the galaxies within our observable universe represent only a minuscule fraction of the galaxies in the universe. According to the theory of cosmic inflation and its founder, Alan Guth, if it is assumed that inflation began about 10−37 seconds after the Big Bang, then with the plausible assumption that the size of the universe at this time was approximately equal to the speed of light times its age, that would suggest that at present the entire universe's size is at least 1023 times larger than the size of the observable universe." http://en.wikipedia.org/wiki/Observable_universe#The_universe_versus_the_observable_universe Link to comment Share on other sites More sharing options...
36grit Posted April 7, 2011 Share Posted April 7, 2011 If the universe is just a cycle of time than it may be infinite. Link to comment Share on other sites More sharing options...
IM Egdall Posted April 8, 2011 Share Posted April 8, 2011 (edited) Just started reading Brian Greene's new book The Hidden Reality. He says that according to inflation theory, there are likely other inflation-caused universes beyond ours. And we are just one bubble universe in a number of these universes. Plus from our perspective inside our bubble universe, it appears "as endless space". But someone outside our bubble universe sees what "appears to be an endless time." (He explains this on pp. 66-71) . And unlike string theory and other quantum gravity approaches, inflation does have substantial supporting evidence . But it is still a work in progress. I'm still trying to digest all this, so all I can say is WOW! Edited April 8, 2011 by I ME Link to comment Share on other sites More sharing options...
Mike Smith Cosmos Posted April 10, 2011 Share Posted April 10, 2011 Just started reading Brian Greene's new book The Hidden Reality. He says that according to inflation theory, there are likely other inflation-caused universes beyond ours. And we are just one bubble universe in a number of these universes. Plus from our perspective inside our bubble universe, it appears "as endless space". But someone outside our bubble universe sees what "appears to be an endless time." (He explains this on pp. 66-71) . And unlike string theory and other quantum gravity approaches, inflation does have substantial supporting evidence . But it is still a work in progress. I'm still trying to digest all this, so all I can say is WOW! Intuitively I am not too keen on all these multiverse universes. Intuitively I think , from a probability point of view there is the probability for all these other universes, BUT that the one that has moved from a probable state to a real state is tho only REAL one. Of course for this universe all that is past is Real all that is future is Probable. I appreciate this opens up all sorts of questions, like whose time, whose future , whose past etc etc As multiverses are not yet proven, they must still be in the region of hypothesis, however probability is a well proven science. So my reasoning is that "The influence and touching of the quantum field is the mechanism for the formation of the cosmos , Or how the cosmos is being Made " MKS 2008 . Link to comment Share on other sites More sharing options...
Riot Posted April 10, 2011 Share Posted April 10, 2011 I agree with the first post. The universe is not defined and therefore finite. Not every single idea, or concept can be infinite. Finite-Boundry theory (A theory I have hypothesized) For example, of computer programing an integer can only reach up to 4294967295. Which is exactly 32 bits (I might be wrong). The numeric system is often thought of as infinite, but is undefinable. Bob can't count every single number of the whole numeric system. The ends, limits, and boundaries are unknown. Can we say for certain that the numeric system is infinite? No, the limitations are unknown (There could be a number that can be found using your calculator but that does not mean it exists in the real world). Can we say that the numeric system is PROBABLY infinite? Yes, if all that is being done is bashing on your calculator. Link to comment Share on other sites More sharing options...
Xerxes Posted April 11, 2011 Share Posted April 11, 2011 The universe is not defined and therefore finite. Your meaning is not clear. In what sense is "the universe not defined"? The numeric system is often thought of as infinite, but is undefinable. Bob can't count every single number of the whole numeric system. The ends, limits, and boundaries are unknown. Again, it is hard to attach any meaning to this assertion. What do you mean by "the numeric system"? Why is the "numeric system" of your choice "not definable"? By stating that "Bob can't count......" you are implicitly talking about a set of "numbers" with uncountable cardinality, say the Real numbers. Is this what you mean? Can we say for certain that the numeric system is infinite? No, Yes we can. A set is infinite if and only if it is not finite, which is precisely your starting point about Bob Link to comment Share on other sites More sharing options...
Zant Posted April 13, 2011 Share Posted April 13, 2011 Well if we assume other universes exists then our universe cant be infinite since where would the other universes be? Although Im aware that space is not like a field but still infinite would be everywhere right since thats all there is ? But it may be infinite in a sense it repeats it self it collapses together again and makes another big bang. Although that last part is a little of topic. in short the universe wouldn't be infinite just really big to us 1 Link to comment Share on other sites More sharing options...
keelanz Posted April 14, 2011 Share Posted April 14, 2011 Well if we assume other universes exists then our universe cant be infinite since where would the other universes be? Although Im aware that space is not like a field but still infinite would be everywhere right since thats all there is ? But it may be infinite in a sense it repeats it self it collapses together again and makes another big bang. Although that last part is a little of topic. in short the universe wouldn't be infinite just really big to us the big crunch is its name our universe is already infinite your just looking at it from the wrong scale, we still havent magnified our own existence to any limit other than practical, so if we had the tools there would be more to discover and thats looking in, if you look out and presume there are other universes we have no idea what our universe could be part of and how infinite that scale is, all we know is our own reality and some of the laws which dictate it things like big bang/big crunch & big planet/small universe are perceptual concepts which if you like could be called infinite space 1 Link to comment Share on other sites More sharing options...
Zant Posted April 14, 2011 Share Posted April 14, 2011 the big crunch is its name our universe is already infinite your just looking at it from the wrong scale, we still havent magnified our own existence to any limit other than practical, so if we had the tools there would be more to discover and thats looking in, if you look out and presume there are other universes we have no idea what our universe could be part of and how infinite that scale is, all we know is our own reality and some of the laws which dictate it things like big bang/big crunch & big planet/small universe are perceptual concepts which if you like could be called infinite space Thats a new way to look at it for me but its still interesting i see what you mean by it. We dont know what our universe is part of the only way to know that is to go and see it from the outside. But there has been proof in mathematical equations that there is in fact other universes but like i said before only way to know for sure is to see it from the outside. The part i dont get is how there can be more then 1 infinite object since infinite means having no boundaries or limits, but it may be infinite since space is bendable so it just bends at the edges. If you could explain this part then id be happy its been nagging on me for awhile thx in advance Link to comment Share on other sites More sharing options...
Zarnaxus Posted April 14, 2011 Author Share Posted April 14, 2011 Lines are theoretically infinite in length. They have no limits/boundaries in their own two dimensions. When you introduce another dimension, the plane, you can have an infinite amount of parallel lines, each infinite in length and coexisting with the others. In the tenth dimensional mega-universe, is it so hard to believe the existence of more than one infinite object? Link to comment Share on other sites More sharing options...
36grit Posted April 15, 2011 Share Posted April 15, 2011 Rebang Theory: By Mark Beal The universe is a plane consisting of time and virtual time. Time is the momentum of reality. When these waves break down they release the energy that they've been carrying. These begin forming virtual particles. This is where time and virtual time transition. As expansion continues time, distance, length, width, and depth, begin breaking down as we know them. The virtual particles build up on the edges and turn into violent storms of chaos and disorder as their magnetic polarity attracts aniahalates pushes and heats until quantum fission occurs and real particles are born once again. Then ofcourse the quarks start viberating and creating hydrogen atoms that explode from the heat and cause more heat and more fusion until you get another period of inflation and a new branch of reality is formed. As far as we know some of the galaxies and stars we observe might have come from a completely different and seperate bang. So there it is time, virtual time, and transitionary "valleys" that make up and define the infinite plane. 1 Link to comment Share on other sites More sharing options...
keelanz Posted April 15, 2011 Share Posted April 15, 2011 Thats a new way to look at it for me but its still interesting i see what you mean by it. We dont know what our universe is part of the only way to know that is to go and see it from the outside. But there has been proof in mathematical equations that there is in fact other universes but like i said before only way to know for sure is to see it from the outside. The part i dont get is how there can be more then 1 infinite object since infinite means having no boundaries or limits, but it may be infinite since space is bendable so it just bends at the edges. If you could explain this part then id be happy its been nagging on me for awhile thx in advance i would presume something like pi "π (sometimes written pi) is a mathematical constant whose value is the ratio of any Euclidean plane circle's circumference to its diameter; this is the same value as the ratio of a circle's area to the square of its radius. π is approximately equal to 3.14159 in the usual decimal positional notation. Many formulae from mathematics, science, and engineering involve π, which makes it one of the most important mathematical constants.[1]" it cant be defined (infinitely long) but is used as a constant. 1 Link to comment Share on other sites More sharing options...
csmyth3025 Posted April 15, 2011 Share Posted April 15, 2011 ...But there has been proof in mathematical equations that there is in fact other universes... I'm not aware of any such proofs. Can you provide a reference? Chris Link to comment Share on other sites More sharing options...
Zant Posted April 16, 2011 Share Posted April 16, 2011 I'm not aware of any such proofs. Can you provide a reference? Chris I saw the proof on tv while i flipped channels more specific discovery (science or normal one) and it was michio kaku talking about multiverses. Short answer to your question no i cant unless you find that clip/episode on the internet somewhere. Hope this clears that up i would presume something like pi "π (sometimes written pi) is a mathematical constant whose value is the ratio of any Euclidean plane circle's circumference to its diameter; this is the same value as the ratio of a circle's area to the square of its radius. π is approximately equal to 3.14159 in the usual decimal positional notation. Many formulae from mathematics, science, and engineering involve π, which makes it one of the most important mathematical constants.[1]" it cant be defined (infinitely long) but is used as a constant. Ok now i understand thank you Link to comment Share on other sites More sharing options...
DrRocket Posted April 16, 2011 Share Posted April 16, 2011 I saw the proof on tv while i flipped channels more specific discovery (science or normal one) and it was michio kaku talking about multiverses. Short answer to your question no i cant unless you find that clip/episode on the internet somewhere. Hope this clears that up Ok now i understand thank you There is no such proof, nor is there likely to ever be. Michio KJaku is a very poor source. He makes flamboyant statements with no basis, apparently in an effort to promote himself and sell books. If Kaku said that the sky was blue, I would immediately seek independent verification. I have several hundred science and mathematics books. I have one by Kaku -- a mediocre book on quantum field theory. I am very unlikely to ever own two. 2 Link to comment Share on other sites More sharing options...
ShmuckersJam Posted April 19, 2011 Share Posted April 19, 2011 Perhaps the universe IS finite. I've always wondered if the universe as we know it might just be a component of something bigger. Perhaps the universe needs a different title, and whatever it is a component of should be "The Universe". Link to comment Share on other sites More sharing options...
csmyth3025 Posted April 21, 2011 Share Posted April 21, 2011 Perhaps the universe IS finite. I've always wondered if the universe as we know it might just be a component of something bigger. Perhaps the universe needs a different title, and whatever it is a component of should be "The Universe". I think the observable universe fits your description. Chris 1 Link to comment Share on other sites More sharing options...
keelanz Posted April 21, 2011 Share Posted April 21, 2011 well can nothing be defined as infinite? -1 Link to comment Share on other sites More sharing options...
Eelpie Posted April 21, 2011 Share Posted April 21, 2011 Just started reading Brian Greene's new book The Hidden Reality. He says that according to inflation theory, there are likely other inflation-caused universes beyond ours. And we are just one bubble universe in a number of these universes. Plus from our perspective inside our bubble universe, it appears "as endless space". But someone outside our bubble universe sees what "appears to be an endless time." (He explains this on pp. 66-71) . And unlike string theory and other quantum gravity approaches, inflation does have substantial supporting evidence . But it is still a work in progress. I'm still trying to digest all this, so all I can say is WOW! The "we have an infinite number of multiverses arising from bubble universes" claim was also made by Marcus Chown in the "never ending days of being dead" he also said that this was a COROLLARY of the standard theory. This seems highly dubious to me but would be interested to know if anyone thinks that the argument is sound. Link to comment Share on other sites More sharing options...
csmyth3025 Posted April 22, 2011 Share Posted April 22, 2011 well can nothing be defined as infinite? I think that to the ordinary layman anything that has no end point can be defined as infinite. This definition is not quite exact, though. For instance, the surface of a sphere has no end point and yet is a finite (closed) surface. Chris Link to comment Share on other sites More sharing options...
owl Posted April 22, 2011 Share Posted April 22, 2011 (edited) I've said this before in other threads, but I challenge anyone here to come up with an "end of space." So, what kind of boundary can anyone imagine such a limit to be? (Hint: It's all in your head.) But say you have a firm idea of a limit to space... so what lies beyond that limit/wall/boundary that someone might have imagined? More space? Of course. There can be no limit to space. I just read the thread and copied a bunch of quotes. I'll make it simple and just reply in bold within the quote box of selected quotes: steevey:“What would be stopping the existence of infinite space? “ Exactly! “There's also something else too, since the fabric of space itself is not proven to exist, even though the universe is said to be filled with virtual particles, there could still be space of nothingness between those, which if thats the case and true space is nothing, there could be infinite "nothing"... Right on. The following may be scrambled (no spaces) due to my old cut and paste program. If so, sorry. It's well spaced in my edit screen and run together when posted so I'm at a loss, not good at this kind of glitch. Decipher it or not. A c c o r d i n g t o t h e t h e o r y o f c o s m i c i n f l a t i o n a n d i t s f o u n d e r , A l a n G u t h , i f i t i s a s s u m e d t h a t i n f l a t i o n b e g a n a b o u t 1 0" 3 7 s e c o n d s a f t e r t h e B i g B a n g , t h e n w i t h t h e p l a u s i b l e a s s u m p t i o n t h a t t h e s i z e o f t h e u n i v e r s e a t t h i s t i m e w a s a p p r o x i m a t e l y e q u a l t o t h e s p e e d o f l i g h t t i m e s i t s a g e , t h a t w o u l d s u g g e s t t h a t a t p r e s e n t t h e e n t i r e u n i v e r s e ' s s i z e i s a t l e a s t 1 0 2 3 t i m e s l a r g e r t h a n t h e s i z e o f t h e o b s e r v a b l e u n i v e r s e . " h t t p : / / e n . w i k i p e d i a . . . . r v a b l e _ u n i v e r s e Zant: “But it may be infinite in a sense it repeats it self it collapses together again and makes another big bang.” Perpetual bang/crunch cycle. That’s the way I see it. Quark View PostShmuckersJam, on 19 April 2011 - 12:13 PM, said: Perhaps the universe IS finite. I've always wondered if the universe as we know it might just be a component of something bigger. Perhaps the universe needs a different title, and whatever it is a component of should be "The Universe". How about taking the word literally, " one verse," with "verse" meaning all there IS, known and unknown. I'll go with "The Universe" as you say. I think the observable universe fits your description. The observable universe is all there is? keelanz Meson well can nothing be defined as infinite? Look at the meaning of the words. To "de-fine" is to make finite, at least in the collective mind, and in the dictionary. Srpace and all that it contains (visible and not) is infinite, by the above argument using logic alone. I welcome any argument with this post. Just be clear on you premise as to what space (and "the universe') is, please. Edited April 22, 2011 by owl Link to comment Share on other sites More sharing options...
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