What would be an example of a physical system in this universe reaching infinity in a finite amount of time?
375753
As far as I know, there are only 2 real-life examples of such a process: the Big Bang and a black hole.\n\nThe Big Bang caused 'everything' to expand into 'nothing'. That in itself is an infinitely large expansion; it's like dividing infinity by 1.\n\nA black hole is, in essence, where matter collapses to zero size, thus reaching infinite density and creating a hole in space-time. Little is known about the interior of such black holes, or, indeed, if there is such a concept.
1113632
What is beyond the borders of the universe?\nIs it truly possible for the universe to go on forever? If there is an end, what’s on the other side?\n \nBefore we can address these questions, we must first define universe.  The word universe denotes all space and everything (matter, energy) contained within it.  The prefix uni means one.  The root verse means word, turn, or whole.  Thus our universe has traditionally been thought to be the one whole of all substance or matter.  Questions regarding our universe persist today.  Does it have a beginning and end, or does it go on forever and ever?  Is it linear or curved?  If it has limits of length or curvature, then what lies beyond the Universe?  If something lies beyond the Universe, then can’t we accurately call that the Universe?\n\nSome lay people and some scientists conceive of the universe as infinite space.  Others define the universe as finite, or limited (perhaps curved), space.  Still others incorporate the elements of matter and/or energy into their definition of the universe, as opposed to the space beyond matter and energy.\n\nGiven these concepts of our universe, some scientists conclude that the “totality of space could be infinite. Shrink an infinite space by an arbitrary amount, and it is still infinite. (Scientific American March 2005).”  \n\nAs to the notion that we live in an ever expanding universe, moving away from every other universe on the fabric of space-time, some scientists are careful to point out that “Andromeda, our nearest large galactic neighbor, is actually moving toward us, not away. Such exceptions arise because Hubble's law describes only the average behavior of galaxies (Scientific American March 2005).”\n\nIn accordance with your supposition that our universe is in another universe, “it has been hypothesized by some scientists that the universe may be part of a system of many other universes, known as the multiverse (http://en.wikipedia.org/wiki/Universe).” Modern astrophysicists talk about multiple "pocket" universes that branch off from one another.  Stephen Hawking points out that parallel pocket universes can have no effect on a real observer inside a single pocket, so, according to Hawking, they are theoretical baggage that should be eliminated from cosmology, the study of the origins of the universe.\n\nSome string theories define the universe as a three-dimensional space in an invisible space having more dimensions. This is, in essence, a universe within a universe.  Our zone, a “braneworld” could periodically bounce into another parallel braneworld.  This may create what would appear as a Big Bang from one perspective or a Big Bounce of alternating expanding and contracting universe from another perspective.  Such a cataclysmic event is thought to occur 300 billion years from now, resulting in the rearranging and creation of a new universe.\n\nBeyond the borders of the universe, there are other universes moving through a multiverse.  While scientists do not commonly believe that our universe goes on for an unlimited distance, despite its present expansion, they allow for the possibility that the multiverse may go on forever.  If there is an end to our universe, what’s on the other side is called the multiverse.  If there is an end to the multiverse, another term may need to be coined to describe what lay people commonly refer to as infinite space.\n\nSteve\n:-D
615823
The Universe is thought to be 'finite but bounded'. That is, it does not come to an end anywhere but somehow loops around again far, far away. Another example of a finite but bounded shape is the surface of a bubble, a sphere. It has definite area and size but there are no edges to its surface, no place to call a "beginning" or "end" that is not arbitrary.
1083084
The Universe cannot be infinite, because it is expanding, which points to its origin where everything began at the same point, namely the singularity of the Big Bang. Therefore, if it is expanding, it is bounded.\n\nHowever, it is thought that it probably doesn't have an edge, much like the Earth doesn't have an edge. If you started in a spaceship and went in a straight line, you would eventually end up where you started, much like if you started at the North Pole and went in a straight line, you would end up back the North Pole.\n\nThe reason: although you would be going in a straight line on the 2-D surface of the Earth, that line is curved in the 3rd dimension. So, if spacetime is curved in the 4th dimension, you could be going in a straight line 3 dimensionally, but it would be curved 4th dimensionally.
1035265
Which is the end of expanding universe? If any end exists, what will be behind this end?\n\nBefore we can address that question, we must first define universe.  \n\nThe word universe denotes all space and everything (matter, energy) contained within it.  The prefix uni means one.  The root verse means word, carnate message, meaningful substance, matter.  Questions regarding our universe persist today.  Does it have a beginning and end, or does it go on forever and ever?  Is it linear or curved?  If it has limits of length or curvature, then what lies beyond the Universe?  If something lies beyond the Universe, then can’t we accurately call that the Universe?\n\nSome lay people and some scientists conceive of the universe as infinite space.  Others define the universe as finite, or limited (perhaps curved), space.  Still others incorporate the elements of matter and/or energy into their definition of the universe, as opposed to the space beyond matter and energy.\n\nGiven these concepts of our universe, some scientists conclude that the “totality of space could be infinite. Shrink an infinite space by an arbitrary amount, and it is still infinite. (Scientific American March 2005).”  \n\nAs to the notion that we live in an ever expanding universe, moving away from every other universe on the fabric of space-time, some scientists are careful to point out that “\n\nAndromeda, our nearest large galactic neighbor, is actually moving toward us, not away. Such exceptions arise because Hubble's law describes only the average behavior of galaxies (Scientific American March 2005).”\n\nIn accordance with your supposition that our universe is in another universe, “it has been hypothesized by some scientists that the universe may be part of a system of many other universes, known as the multiverse (http://en.wikipedia.org/wiki/Universe).” Modern astrophysicists talk about multiple "pocket" universes that branch off from one another.  Stephen Hawking points out that parallel pocket universes can have no effect on a real observer inside a single pocket, so, according to Hawking, they are theoretical baggage that should be eliminated from cosmology, the study of the origins of the universe.\n\nSome string theories define the universe as a three-dimensional space in an invisible space having more dimensions. This is, in essence, a universe within a universe.  Our zone, a “braneworld” could periodically bounce into another parallel braneworld.  \n\nThis may create what would appear as a Big Bang from one perspective or a Big Bounce of alternating expanding and contracting universe from another perspective.  Such a cataclysmic event is thought to occur 300 billion years from now, resulting in the rearranging and creation of a new universe.\n\nWhich is the end of expanding universe? That may be determined in 300 billion years, when it stops expanding (like a balloon).  If any end exists, what will be behind this end?  A multiverse void containing other expanding and contracting balloons, referred to as universes, may exist beyond our own.\n\nSteve\n:-D
245031
Yes this is a hard topic to understand the only way I can explain it is to imagine that space "curves" onto itself. Thus is finite.\n\nThe reality is an actual infinity can not exist, its something conceptual, impossible lack understanding of what an actual infinity is, it can exist mathematically as an Ideal, but not in reality as that is physically impossible.\n\nLook at the attributes of infinity:\n\n(1) You can not add to infinity\n(2) Any part of infinity is the same as the entire "set"\n\nWhen we trace our Universe back to the big bang we end up with a singularity, this is where "Science and physics break down" it can not be really explained and we have to go to a higher source of knowledge i.e. theology.\n\nWhat I will end on is saying that one of the Attributes of the Creator is that he is infinite.\n\nI hope that helps\n\nAnhar Hussain Miah
71518
Time is infinite, the end will never come.
300537
There is disagreement over whether the universe is indeed finite or infinite in spatial extent and volume. Many astronomers and cosmologists believe the universe is infinite due to recent findings in NASA's WMAP project supporting a flat (therefore infinite) universe\n\nHowever, the observable universe, consisting of all locations that could have affected us since the Big Bang given the finite speed of light, is certainly finite. The edge of the cosmic light horizon is 13.7 billion light years (4.19 Gpc) distant. The present distance (comoving distance) to the edge of the observable universe is larger, due to the ever increasing rate at which the universe has been expanding; it is estimated to be about 78 billion light years (7.8 × 1010 light years, or 7.4 × 1026 m). This would make the comoving volume, of the known universe, equal to 1.9 × 1033 cubic light years (assuming this region is perfectly spherical). The observable universe contains about 7 × 1022 stars, organized in about 100 billion galaxies, which themselves form clusters and superclusters. The number of galaxies may be even larger, based on the Hubble Deep Field observed with the Hubble Space Telescope. The Hubble Space Telescope discovered galaxies such as Abell 1835 IR1916, which are over 13 billion light years from Earth.\n\nBoth popular and professional research articles in cosmology often use the term "universe" when they really mean "observable universe". This is because unobservable physical phenomena are scientifically irrelevant; that is, they cannot affect any events that we can perceive.
292639
as the table is frictionless a constant force will take it to infinity...... it will never stop....
626622
The universe is an indefinite entity.It is bounded by 'nothing' even in the strict sense of modern physics.
38951
The universe has no center, but it is not infinite.  It is finite but unbounded, like the surface of a golf ball.  The surface does not have a center nor a boundary, but it is not infinite.
722611
the universe is constantly expanding although the rate is slowing and never reaches zero.\nexperts believe that the universe is finite yet has no edge, just like the surface area of a sphere. this could imply that if u reached one 'end' of the universe, u would end up on the opposite side or something like that
674188
well, spacetime does not seem to end, and nothing is "holding up" spacetime.\n\nthe universe is not infinite. the universe is finite yet has no edge and no center. it may be something like the two dimensional surface of a sphere. nothing inside or outside the sphere exists for the two dimensional surface.\n\nalso, i have something for you to think about. the radius of observable universe is about 46 billion lightyears, yet the universe is 13.7 billion years old.
983642
Actually, they know it isn't infinite.\n\n\nThe findings are mostly thanks to hubbles big idea and discovery, but they can now confirm that indeed the visible universe is finite thanks to WMAP.\n\n\n\nAs for the possiblity of space outside of the visible universe...we have no idea.
519258
Actually we don't even know enough about the shape of the Universe to affirm that the Universe is infinite or not.\n\nSuppose we put an ant on a infinite sheet of paper. The ant is short-sighted and sees only that close to him his universe look pretty flat. If he starts walking he will never meet a boundary and never come back to the same place again. The two-dimensional plane is infinite and without bounds.\n\nNext put the ant on a large sphere. Again our ant can not see far enough to observe any curvature. If he starts walking in one direction he will never come to a boundary, but this time he can make a roundtrip. The spherical universe is unbounded but finite.\n\nWe are in the same position as the ant, but in three dimensions. Locally our Universe seems flat and unbounded, but we don't know if we are in the 3 dimensional equivalent of the plane or the sphere. In the first case the Universe would be infinite, in the second place it would be finite.\n\nNow the fun and speculation starts....\nEven weirder shapes are possible. In two dimensions our ant has a third possibility, a universe shaped as a torus or a donut. We can make a torus by taking a sheet of paper, roll it up in a cylinder and then glue the two open ends together.\nThe torus also has a three dimensional equivalent. Take a cube and imagine the following rule: everytime we leave the cube-universe through a side, we immediately enter it again to the side opposite. It is as if the opposing sides are glued together.\n\nStrange? Yes, but not excluded...\n\nMy current favourite shape for the Universe is the following. Think of *two* three dimensional spheres. We live inside one of the spheres. A spaceship that flies to the boundary of one sphere immediately reappears on the corresponding point on the boundary of the other sphere and continues its voyage there. It is as if the boundaries of the two spheres are somehow glued together.\n\nNeat, isn't it?
55707
You get into Quantum Theory with your intrigue and there is no evidence to support that the universe is not infinate.\n\nHOWEVER, according to the Big Bang theory there was nothing and then there was something in a centralized location millions (billions) of years ago. At the speed that the universe is spreading outwards there has to be an end to it and scientists are trying to get telescopes powerful enough to see to the beginning of time.\n\nWhat lays on the other side? Nobody knows.
70871
Infinity has no value.  It is a concept of going on forever.