why is the universe expanding?
478807
According to the experts, there has been a rise in the latent energy of the Higgs field
1081007
Fun stuff, this gravity question. One of the leading hypotheses of the past was that the expansion of the universe would eventually slow, and gravity would then pull all mass back together, resulting in another singularity, and a recurrence of the big bang. \n\nRecent evidence says that this isn't happening. Instead, as the universe expands, the gravitational pull will approach zero. The consequence of this new hypothesis is that the universe will eventually spread itself into nothingness, and as the stars fade and run out of fuel, the universe itself will fade away into cold and darkness. Not that it's something we have to worry about anytime soon.
384787
The universe is curently about 156 billion light years across, expanding at a rate of 71(+/-4) kilometers per second per megaparsec. Current observations dictate that this rate is accelerating.  So we will go on, and on, and on for eternity
941884
It's a big mystery. I have read that initially, at the onset of the Big Bang, all the matter of the universe existed as a singularity that was infinitely dense and it, suddenly, expanded several times the speed of light. Once the expansion, or explosion, occurred the mass was no longer homogenous, but was clumped together, which can explain the formation of the planets, stars, etc. It's funny that all the big brains of the scientific community can tell you what happened .1, .01, .001 seconds (and so on) after the big bang, but none of them can tell you what occured the half second before.
574337
There are various conflicting theories about this.Some say universe will keep on expanding.Some say it will be a see saw .Some say it will all end in a big contraction.It's still a open question.
1168465
He discovered that the universe was expanding.
5808
Nobody really knows for sure.\n\nThere's a theory that the universe is expanding in a spherical shape and will continue to expand until it reaches maximum entropy. At that point all of the energy and matter in the universe will be equally distributed and the universe will no longer be able to support life.\n\nThere's another theory that the universe will expand (again, roughly in the shape of a sphere) until all of the galaxies exhaust their kinetic energy. At that point the universe will begin contracting. When the contracting is complete a singularity containing all of the mass in the universe will form and explode in a big bang.\n\nIf you think about it, if the latter theory is true then it's possible that the universe has expanded and collapsed an infinite number of times in the past!
158254
Universe is not exactly rotating or spinning... it is said to be constantly expanding... and sorry i don't know about the big band
450787
When talking about the universe, asking "why" something is the way it is usually has no absolute, 100% answer.\nThe best answer to your question is that the universe somehow began over 13.7-billion years ago and immediately began expanding. The expansion has gone on, steadily increasing the size of the cosmos until we observe its vastness today.\n\nGod should be spelled B-I-G B-A-N-G\nPBrax@netscape.com
1015629
Your thinking is good, but you have to take into account the distance scales involved. On the scale of the entire universe, space is indeed expanding, but on the relatively tiny scale of distances in our solar system, the expansion is miniscule. Also, the gravitational forces involved with holding the planets in their orbits around the Sun easily overcomes the expansion rate.
686202
Universe theories talk about a finite and unlimited Universe. The Universe is unlimited because it has no boundaries. There is no edge, no end where a spaceship would have to stop. See it as a tiny bug walking on the surface of a big balloon. The ballon has a finite dimension, but the bug will never find the end, so it is unlimited from the bug's point of view.\nSo, the Universe can be expanding or contracting or staying the same size. This is a very important question to answer in modern astronomy. Latest studies say that it is expanding, but it has not been totally proved.\nAnd where it is expanding? The Universe is creating more space and time where there is nothing.
862094
The space between the galaxies is what is expanding.  Imagine raisin bread being baked.  As the bread rises, each raisin moves away from every other raisin.  Another way to visualize this is by drawing dots on a balloon then blowing the balloon up.  As the balloon get's bigger, each dot moves further away from every other dot.  It's the same for galaxies.\n\nNow the expansion of the universe is only detectable at extremely large distances.  Nearby galaxies like M31 can move towards us.  But most galaxies we see are extremely far away, so almost all of them are receding from us.
163028
Science states that the universe is ever expanding, but another theory believes that the universe will eventually fold back in on itself and will crush itself into nothing. Such an implosion will have to create an opposite reaction (an explosion) which will allow another universe to expand outwards.\n\nFollowing that theory, one could deduce that our universe was born when the previous one died.
680741
Well we couldnt go to the end.. because time is what results from the universe expanding.. so as time goes on.. the universe keeps growing
757860
One of the latest theories (not widely accepted) is that it was caused by the interaction of two other universes at the sub-atomic super-string level. This collision caused a catclysmic explosion at a  point of singularity, creating all the matter and energy we now have in our universe, which then began to expand and cool. \nSimple isn't it?\n\nAnother theory is that the universe is a state of perpetual pulsation. It expands, and then crashes in on itself to a singularity point, and then explodes again, this has been going on forever.\nEven simpler isn't it?\n\nThis could explain why so many people believe in God. It is simpler to understand. \n\nWhich theory you believe is up to you.
465735
The Universe is Expanding because it has been observed that the galaxies within the Universe are moving away from us at tremendouse speeds. The Doppler Effect explains the red shift observed through hundreds of telescopes which confirms the fact that the galaxies are moving away from us. If the Universe were not expanding, then the Galaxies would not be all moving away from us, but moving with us. The more perplexing question is if the Universe is expanding, then it is expanding into what?
275416
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?