Why is the universe so close to the dividing line between collapsing again and expanding indefinitely?
155835
The problem is to tabulate the total mass of the Universe, a realy BIG problem.  There may be a lot of undetected dark matter in the universe that would shift calculations of the Gravitational Constant that will determine the fate of the Universe.  It is like trying to count the mushrooms in a totally blacked out cellar while blindfolded, or even much harder.  Progress is being made as the limits of the Universe are being explored by every means possible, especially by use of the human brain.
594695
The universe cannot have an end, it has to be infinite and completely symetrical. This leads to three possible scenarios for its shape a saddle shape, a spheroid, and a flat plane. Different experiments have led scientists to believe that space is an infintie flat plane. The main reason why we know that if there were edges to space then we would have to me moving towards some objects and away from others. This is not the case as all observed entities are moving away from us. This leads to the assumption of a infinite expanding universe. \n\nAs far as our perception is concerned we are not inside of anything since the universe occupies all of the space that we can observe so the universe is everything. But if somehow you could step out of our universe into a higher dimension you dont know what you would see. There are some theorists who believe our universe is one of many universe. But since there is no way to see out of the universe we may never be able to answer this question. I agree that if you start thinking in this manner it can get quite perplexing\n\nTo the person who said space must have an edge to expand think of a baloon. If we go down a dimension imagine that our galaxy is a penny glued on the surface of a baloon. To us the baloon has no edges at all since we cannot see out into the third dimension, yet the baloon is expanding. So from our vantage point we live on an infinite surface that is expanding and causing nearby pennies to all travel away from us.
703604
The universe is still expanding, and so far it's been dated at several billion years old, so assuming it began to collapse again, it would likely take just as long, before an immense black hole forms again and then there's another big bang.\n\nMy guess is that we'll be gone long before that, since our species uses more natural resources than the Earth can replenish.
14387
"There is disagreement over whether the Universe is finite or infinite in spatial extent and volume.\n\n"However, 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, since the Universe has been expanding; it is estimated to be about 78 billion light years (7.8 × 1010 light years, or 7.4 × 1023 km). 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\n"Both 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. See also Causality (physics).\n\nWe live in the centre of the Universe that we observe, in apparent contradiction to the Copernican principle which says that the Universe is more or less uniform and it has no distinguished centre. This is simply because light does not travel infinitely fast, and we make observations of the past. As we look further and further away, we see things from epochs (times) closer and closer to the limit of time, which equals zero, according to the Big bang model. Since light travels at the same speed in any direction towards us, it is reasonable to suggest that we live at the center of our observable Universe."
760374
Scientists say it is expanding. If true, that would mean that the universe is not infinite. It also suggests a beginning.\n\nGood question. Reminds me of my childhood imagination. I imagined a brick wall at the very edge of the universe. Then, however, I wondered what was on the other side of that brick wall.\n\nI wonder what the scientists are saying about it? I bet they don't know either.
962950
This sort of question generates the highest percentage of false and meaningless responses of any other I know of in A&S forum. Here's the real poop. According to the BB model of the universe, the universe is expanding, but there is no boundary beyond which there is only empty space into which stars and galaxies are expanding into. This is a common misinterpretation due to a widespread inability to grasp the concept of curved space. On a large scale, every can consistently be presumed to be pretty much the same as it is in our neighborhood, although any conclusions about what lies beyond the observable universe are impossible. However, the volume of the universe may be either finite or infinite. This is simply not known. In General Relativity, finite *and* unbounded is not a contradiction.
830256
The universe is still expanding and speeding up, faster and faster.  The outskirts of the universe can boggle the mind.  It has been thought that the mass of the universe would eventually stop the outward push and eventually draw it back to implode in on itself, then repeat.  Like a thirty billion year old flower.  Now it is believed that the universe will die a cold death with the universe continually speeding off in all directions.  Maybe we will run into another universe that is moving towards our own.  And no we will not fall off a cliff, the universe is expanding at a uniform rate in ALL directions.  There will be no drop-offs...
178670
If the universe is infinite, it doesn't mean that everywhere is the center, it means that it has no center. Or, if you mean relative to the existing matter...well, that isn't infinite, and has a defined center.
1174337
Yes.  I think (and I think some scientists have discussed this on public TV) that a universe (either in our dimension, or another) was gradually, then more quickly, collapsing into itself, like a black hole, and that caused the bang, and the cycle repeats itself.  They think this because the universe is expanding; when it reaches its maximum limit (and I don't have any idea what causes that limit, etc.) then it starts to reverse direction, and start collapsing in on itself again, and starts the whole process over again.  In a couple of quintillion years).
1056226
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.
127551
Because the universe is a vacuum and there's nothing to stop it from expanding. This is assuming that the big bang theory is correct and it's expanding because of the explosion .
800785
Ah yes, people like to give mumbo jumbo bullshiet answers to this question to confuse you further.\n\nThe thing is, we really have no idea. This is half the reason the answer is so confusing.\n\nScientists, like myself, have defined the universe as everything and like to say it isn't expanding into anything because, quite frankly, they don't know what's going on and it's easier to just define the universe as that for the time being. I don't know, neither does anyone else.\n\nFrom recent science, we know that the universe is absolutely finite, therefore it's size is increasing; it is getting larger. This can also be seen by looking at microwave radiation maps of the universe.\n\nSo then, what is it expanding into? Well, if ANYONE could answer this question, they would probably go down in history as greater than even people like Einstein, Newton, Galileo...but the reality is, we don't know. All answers to this question are purely spectical and usually formed to fit a belief system that has been adapted from that person.\n\n\nPersonally, it's probably expanding into more space, which probably contains an indefinite number of universes and extends infinitely.\n\nBut that is only my personal view. Just like all other views.
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.
1075314
The current status of the universe actually does work like that.  Technically, with gravity the universe should collapse back upon itself and the big bang would occur all over again.  However, gravity is one of the weakest forces in the universe.  With that said, it has been measured that the universe is expanding and accelerating at a rate that exceeds the gravitational forces required to initiate the "big crunch."\n\n\nThere are two schools of thought right now.  One is that the universe will continue to decelerate but never completely stop or collapse upon itself.  More recent theories have stated that the universe appears to be accelerating.\n\nAs it stands now, I would say that it is safe to say that the odds are extremely low of the universe collapsing back to a singularity.\n\nSee the link below for some more information.
1184658
The universe is incomprehensibly large and, please, don't try to argue it isn't - it is - no person who has ever lived could draw a comparison between the size of the universe and ANYTHING else - there is absolutely NOTHING to measure it against.  I've read articles saying scientists are able to see to the center of the universe now - I'm sorry but that is garbage - the universe is endless.  You can not see the center of something that is endless or, infinite in size.\nI'm not perfect, I admit there may be flaws in my logic so, please, help me learn if you think you have something to add.\nSince the universe is never ending, the odds are minuscule there are no other sentient beings anywhere.  I can't even begin to comprehend how minuscule - in fact, I doubt they can be calculated - if the universe is endless they can not be.\nThis leads me to believe there are aliens in the universe.  It's possible that aliens are here and have been here for a long, long time - but it's also possibly they've never been here.  \nWhat would an alien look like?  There is no way of knowing.
387616
Originally it was thought that the expansion of the Universe was slowing, and would eventually stop, reverse, and end in a "big crunch".  Now it appears as if the expansion is not only *not* slowing, it's actually accelerating!  As close as we can tell, this expansion will continue until the Universe dies of cold-when the reaction potential reaches zero, and all the energy is lost either to waste heat or inert matter.  However, it is clear we have a very poor understanding of the Universe and what it is composed of, and the forces that drive it (the expansion, for example, seems to require a new force that opposes gravity).  There is also the possibility that humans, or some other intelligent species, will over the next few billion years, achieve enough knowledge and power to change the fate of the Universe.
52550
I believe the universe is a 'closed' shape, meaning that there is no 'edge', however it does have a finite size.  But just to entertain your question, if we one day did reach the End of the Universe we literally would be unable to describe anything on the otherside.  Everything we know about physics, space time, the fundamental forces, the universal constants and so on only exist in this universe.  Anything 'outside' of the universe could potentially then have different laws of physics and thus would be completely beyond our comprehension.  Words would literally fail.  For more fun reading, checkout the link in the sources.