If the universe is expanding, what is happening to the space between atoms, molecules etc.?
464239
The expansion happens everywhere, but things that are bound together even moderately, do not experience it reletive to what they are bound to.  You don't notice it in the solar system, our own galaxy, or even the local galaxies near by.  This is because the gravitational force is enough to overcome the exansion.\n\nSimilarly you don't exapand (due to chemical bonds), and electron orbits, governed by QED (advanced form of electromagnetism) don't change their size.  In a sense you will only notice it with objects that you are basically unconnected with.\n\nWe don't notice the cosmic expansion until we either look at galaxies and objects very far away, or look at light that has traveled vast distanced before it reaches us.
533024
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
626822
The Universe is expanding, but it doesn't have a phyiscal start, middle, or an end.  It's going to expand forever. Don't think about it, because it's not something our mind can really grasp.\n\nHere's an analogy that helped me:\n\nImagine the Universe as a two dimensional place.  The Universe is the surface of a rubber ball.  There's no start, finish, or middle.  As the Universe expands, the rubber ball fills with air.  Still no start, finish, or middle.\n\nFor a long time, it was unknown whether the Universe was open or closed, meaning whether the Universe would expand forever or eventually collapse back on itself back to nothing.\n\nThe hubble telescope proved that the Universe it open and would expand forever.
410246
Well, this is uncertain. I will explain it as it is currently understood. There are three possibilities based on relativity and the Standard Model. There are three types of expansion depending on the mass-energy density of the universe - open, flat and closed.\n\nIn an open universe, expansion will continue and will actually increase with time. This is because there is not enough mass and energy in the universe to pull it back in.\n\nIn a flat universe, the universe will continue to expand, but expansion will begin to slow at a certain point and as time approaches infinity the expansion will stop. Of course, since infinity means forever, the expansion will continue but slow down constantly, little by little.\n\nIn a closed universe, there is enough mass and energy to cause a collapse of the universe, known as the "big crunch."\n\nAnyway, current theory holds that we live in a flat universe and that inflation will continue forever, as mentioned.\n\nOh. It expands into nothing - as in before the universe is there, there is nothing there.
317862
Size & volume of the current universe have little bearing on how "big" or "small" the singularity was at the moment this universe came into being, since the structures of the various sub-atomic particles that make up atoms and unltimately the "stuff" you have difficulty in "compacting" were not yet defined sufficiently for your question to have meaning.  Not that it's a bad question.  It's just in the same family as "well i know the Universe is infinite, but what's outside it?"\n\nStephen W.Hawking might be a good place to start.
1101873
First I will address your difficulty with the answer someone gave to your earlier question.\n\nSpace is expanding between distant parts of the universe, and presumably very slowly on local scales too (~100 km/s per MPC, works out to about 100 nm/s over a distance of a meter.  Hmmm, I wonder if one could devise an experiment to measure that. . . )  \n\nLocally, things like gravity (in the case of a galaxy) or electromagnetic forces (in the case of a less than planet sized solid) overcome that expansion. If everything in space was expanding uniformly, we would never notice that phenomenon, because the "rulers" we use to measure distance and size would be expanding too! \n\nSo, you can throw your baseball, and maybe space will expand between the two of you as it travels, however the friction between the two of you and the ground, and the chemical bonds and electrostatic forces in the strip of ground between you and your dad do not permit the two of you to be dragged apart by the expansion of space during the ball's travel time, just as those same forces prevent your body from expanding with the expansion of space.\n\nThe answerer was incorrect in their generalization. I will take a look at this earlier question you asked; in context the part of the answer might be OK, but it appears to be too general a statement the way you presented it.\n\nKeep questioning answers;  you have the makings of a good scientist, philosopher, lawyer or other combination creative and analytical  endeavour.\n\nYour more general question was about movement in "space-time." If you define movement by a change in space-time interval, then the difficulty is in staying still!  In fact, you have to move through 3-D space at the speed of light to experience zero change in the space-time interval between two events; only light itself is frozen in space-time in those terms.\n\nWiki has a good section on space-time intervals:\nhttp://en.wikipedia.org/wiki/Space-time_interval#Basic_concepts
83937
Yes the universe is expanding, thanks to dark energy and perhaps the shape of space itself.\n\nThe space, as far as I know, existed already. From what I understand, our universe exists within a 5th dimension. The "big bang" was really the collision of two membranes that caused a big release of energy along the contact surface and the formation of all matter (initially in the form of a quark-gluon plasma). This matter has kept expanding since and can probably expand indefinately along the 5th dimensional membrane, but there's really no way to know. Some speculate that the reason the expansion of the universe is accelerating right now is that we are in for another collision at any moment, which will destroy all matter as we know it. Sleep tight.
667215
An interesting theory!  What do you think it will start coliding with?  Actually as space expands, the matter within it becomes farther and farther apart, so there is less and less chance of colisions.  \n\nThere are two aspects of the curvature of space.  Local curvature is caused by (or causes) gravity - masses curve the space around them.  But the entire universe may be curved on a great 4-D sphere.  \n\nThe third link below gives an excellent discussion on curvature and the expansion, including an explanation of the density parameter.  If the density parameter is less than 1, then the universe will expand forever.  \n\nAstrophysics and cosmology are pretty fascinating topics.  Keep asking questions and, when the time is right, take some classes in these subjects (take lots of math first!).  The scientific world needs folks who can think outside the box!
314231
The boundry of the universe lies at the outer limit of expansion of the space-time continuum.  It's a popular misconception that the universe is expanding into space.  The truth is that space-time itself is expanding, carrying all the matter and energy in our universe along with it. I should also mention that the 4th dimension, mentioned in other answers is, in fact, time. It is already included in the whole time-space continuum. As for what lies "outside" the universe, the question is in one respect meaningless.  Since it is space and time that is expanding, there is no "outside" in any meaningful sense of the word.  All the space that exists does so within the bounds of our universe.  I know what you are trying to say is"What is our universe expanding into?" but again, that question cannot be answered meaningfully.  We can't even set up mathematical models that are more than speculation because the laws of physics as we understand them are applicable only within the framework of the T.S.Continuum they exist in. Some have speculated that there may be other universes that lie "outside" our own, and there is a body of mathematical models to support this idea, but the plain truth is, no one knows for sure. If such universes exist, they will probably function under differing "laws" than our own, and will be difficult, if not impossible to comprehend. As for what lies "between" universes-as it is "something"(for lack of a better term) that falls completely outside of any human experience or frame of reference, there are no words to describe "it."  You may as well call it the Tao- that's about as close to describing it as we will ever likely get.
297208
As my education impressed on my mind; there is no empty space.  What we think of as "space" is not empty but a constant dance of virtual particals (protons/antiprotons, etc) constantly appearing out of the vacuum travelling a short distance, then touching and annihilating into nothing once again.  \n\n"Empty" space is filled with these interactions which I believe are known as vacuum fluctuations.  The law of "convservation of energy" is really something that holds on average.  Another principle called the uncertainty principle states that we cannot measure simultaneously the energy and time of a (system of particles?) more accurate than a constantant called h or hbar (a very small but finite number). \n\nSo in theory the universe can "borrow" energy from nowhere as long as that energy is returned before the h bar uncertainty in time runs out.  And thus "empty" space is filled with these vacuum fluctuations and is not really empty after all.  Of course I don't think I explained that too well.  See "In Search of Schrodinger's Cat" by John Gribben for a more coherent description
441363
In addition to memac63's pretty good answer, intergalactic space and the entire universe is filled with other "things" that don't necessarily have any solidity -- dark energy (the mysterious force that's causing the universes's expansion rate to increase), gravity (its range is infinite), and something called the cosmic microwave background radiation which is the "afterglow" from the Big Bang.\n\nGod should be spelled B-I-G B-A-N-G\nPBrax@netscape.com
525769
the universe is expanding into "nothing", is that so hard to understand? yes it is. according to the latest version of string theory, our universee is just one little speck in a whole giant "Landscape of probabilities", with as many probabilities as 10 to the power of 500, and more then 500 dimensions, so can you imagine living in a world with 500 dimensions? no! its impossible to imagine. \ntry to imagine our univers being a giant balloon constantly expanding, outside of this balloon there is nothing, void, by expanding, our universe is creating Space-time as it expands. i know some of those concepts are simply impossible to visualize, but mathematically it make perfect sense.
311625
Well, all molecules are constantly vibrating ie changing positions all the time. And yes, intermoleculer forces exsist between. Think about this: do these intermolecular forces require a meduim? This question kinda indirectly relates to the Theory of Nothingless but have a look at the nothinglesstheory website. It's quite interesting. You can find it by googling or from my source list or other resources you may come across. It kinda relates to physics more than chemistry, in  my opinion. In the universe, it began a state of nothing and now after the "Big Bang" there's "everything"... the universe is mostly made up of empty space, just like at atom being made of mostly empty space~\n\nGood question. I hope I've answered your question.
710329
I hate to be the philosopher but that is why the question still reamins. No one can accuratly tell what lies beyond the boundries of the universe. Is there another? Is it just white noise? I believe that space is infinite and our "universe" could well be a part of a cluster of "multiverses". i was once told that the universe is expanding in the same way that a balloon is blown up. So what lies beyond our universe? I say space, space, and more space! \n\nIf our universe began with the "big bang" then that would mean that at some point the universe had collapsed upon itself, leaving empty space.
349458
There currently is a "limit" to space; however, the universe is still expanding from the Big Bang, so the edge of space is constantly moving away from a central point. Beyond this, there is nothing, but unfortunately, this is almost impossible for our brains to conceive because the laws of physics that make up our known world do not exist outside the known universe.
1082539
Drunk again?? No problem. The Universe is expanding outward at about the speed of light and the "edge" that you refer to is the actual outer boundary of our Ubiverse as it contines to expand.  Outside of our Universe, or the absolutely empty vacuum that the Universe is expanding into has no light to shine into our Universe.  It is a totally dark, empty, absolute zero cold, infinite vacuum.
10073
The size of the universe in terms of length, width, height, time is in a state of flux. At any instant it may be expanding or contracting. The universe is generally accepted to be currently expanding. \n\nM Theory (the conglomeration of the 5 superstring theories) tells us that the universe is the result of, so called, “membranes” colliding in such a way that create a pocket of space which we call the universe. If M Theory is accurate, it is probable that there are many universes just as there are many planets, solar systems, and galaxies. \n\nFor more information:\nhttp://en.wikipedia.org/wiki/M_theory