Is this theoretically possible?  Can the universe (infinity) be likened to a grain of sand?
133089
I don't know if it theoretically possible; I suppose you could see a grain of sand as a microcosm of the world or universe. \n\nPoetically:\n\nTo see a world in a grain of sand\nAnd a heaven in a wild flower, \nHold infinity in the palm of your hand\nAnd eternity in an hour.\n\n--William Blake, Auguries of Innocence
613729
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.
599198
If the universe is everything, then what is it expanding into?\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.  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\nIf the universe is everything, then what is it expanding into?  It seems that our universe is all matter, space, and energy that we can perceive in this closed system.  However, that does not mean that there is not additional matter, space, and energy outside our universe.  In other words, there are probably other universes.  Therefore, the zone that we call our universe (or braneworld) may be moving through or expanding into other universes (or braneworlds).  In sum, all universes may be moving through a multiverse.\n \nSteve\n:-D
499639
Could be an infinity of parallel realities. Proof???  Not one bit.
604501
No matter how many 'experts' around here claim that there are alternate universes or other dimensions or a brick wall, nobody--repeat NOBODY--really knows. Tons of theories, but not one single shred of evidence to support any of them.\n\nScientific research has repeatedly indicated that our universe is infinite in scope, and that it will expand forever although its contents (mass and energy) will very, very gradually fade away to nothing.\n\nBefore our universe began, and right now, there's probably nothing else but an absolute and infinite void totally without energy, mass, spacetime, dimensions or anything else.
255034
In spite of what some yo-yo answered, the universe IS expanding, but whether or not it's expanding inside something else is absolutely and totally unknown. In the far distant future our science might have progressed to a point where we'll have the means to answer that question. Instead of driving yourself goofy over wondering what our universe is inside of, best to just try and imagine an absolute and infinite void totally without space, time, energy, mass, or anything else.
131776
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.
495537
There is nothing called the end of the Universe. There are three possibilities of the shape of the Universe.\n\nFirst, the Universe might have what we call positive curvature like a sphere. In this case, the Universe is called "closed" and it has a finite size but without a boundary, just like a baloon. In a closed Universe, you could, in principle, fly a spaceship far enough in one direction and get back to where you started from.\n\nThe second possibility is that the Universe is flat. This kind of Universe can be imagined by cutting out a piece of a baloon material and stretching it with your hands. The surface of the material is flat and not curved. You can expand and contract it by tugging on either end. Flat Universes are infinite in extent and have no boundaries.\n\nFinally, the Universe might be "open" or have negative curvature. Such Universes are also infinite in spatial extent and have no boundaries.\n\nThus whatever be the shape of the Universe, there is nothing called a boundary and hence nothing called the edge or end of the Universe.
21686
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.
114017
The universe is said to be expanding,at least in the sense\nthat all of the galaxies are supposed to be drifting farther\naway from each other.That would seem to contradict your notion of a tremendously big circle as there's no gravitational pull binding them together.\n Also,if space is finite...then what's outside the boundaries?
641165
If you want an answer based on the known theories or experiments... they all will fail on the very assumption of something moving at speed greater than speed of light.\n\nBut in principle.... if something like that can be done.. it would be possible if not clearly see.. but record such events.\n\nMicrowave Background Radiation (if you have ever heard off) are the signatures of what must have happened at time of birth of universe i.e. just after big bang.
100457
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
303300
Just one doubt about your  theory,how do you know that only one big bang has taken place as you say that a second one is coming up???And tell me how you would accelerate something to the speed of light as the mass would become infinite.\nAnd according to your theory the total energy in the universe will go on increasing.You are stuck in a viscious circle!!!
269605
there are stars out there that haven't been discovered yet.  There is a finite amount of atoms in a grain of sand.  The period at the end of this sentence can hold about 250,000 atoms across.  So a grain of sand would have less atoms than there are stars in the universe.
262029
Is our universe in another universe?  \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 “\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.  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\nIs our universe inside another universe?  Well, apparently the Men in Black had it right.  Our universe seems to be inside of something else, another universe, called the multiverse.\n\nSteve\n:-D
488970
The universe is driven by entropy. Its energy on the whole stays the same, but that energy started off in a small number of very hot things and over time is being redistributed to a much larger number of cooler things. \n\nOne possible fate of the universe is that this will continue indefinitely until every particle in the universe has about the same energy. Nothing else would then ever happen in the universe. The temperature of such a universe would be everywhere very, very cold (below 4K).
118390
The Universe IS Infinite !!! \n\nThe shape of the universe is determined by a struggle between the momentum of expansion and the pull of gravity. \nThe rate of expansion is expressed by the Hubble Constant, Ho, while the strength of gravity depends on the density and pressure of the matter in the universe. If the pressure of the matter is low, as is the case with most forms of matter we know of, then the fate of the universe is governed by the density. If the density of the universe is less than the "critical density" which is proportional to the square of the Hubble constant, then the universe will expand forever. If the density of the universe is greater than the "critical density", then gravity will eventually win and the universe will collapse back on itself, the so called "Big Crunch". However, the results of the WMAP mission and observations of distant supernova have suggested that the expansion of the universe is actually accelerating which implies the existence of a form of matter with a strong negative pressure, such as the cosmological constant. This strange form of matter is also sometimes referred to as the "dark energy". If dark energy in fact plays a significant role in the evolution of the universe, then in all likelihood the universe will continue to expand forever.  \n\n\nThe density of the universe also determines its geometry. If the density of the universe exceeds the critical density, then the geometry of space is closed and positively curved like the surface of a sphere. This implies that initially parallel photon paths converge slowly, eventually cross, and return back to their starting point (if the universe lasts long enough). If the density of the universe is less than the critical density, then the geometry of space is open, negatively curved like the surface of a saddle. If the density of the universe exactly equals the critical density, then the geometry of the universe is flat like a sheet of paper. Thus, there is a direct link between the geometry of the universe and its fate.