Is there any  constrains at the outskirt of the Universe?
358909
There is no "outskirt" to the universe-Each point is the center, just as every point on the surface of a sphere is a center.  One of the primary engines of motion is gravity, which is a warping of space/time.  There is a "thing" we call space/time, which has certain properties, but not necessarily substance (as mass, for example).  According to current theory, at the sub-quantum level, there is a bubbling of space/time in which energy is created and destroyed, but it exactly evens out-the "zero-point" energy.  So, yes, there is a thing called space-time which allows things to exist, but no, there is no outskirts of the universe.
1159722
Well - the universe is infinite in so far as it can have an infinite distance.  However, if you take the classical approach, you can assume that the universe is at LEAST twice as wide as the distance light has travelled in the billions of years since the Big Bang, or moment of creation.  The reason is that the Universe contains all things, and it's width can be measured as the point between the two things at greatest distance from eachother.  The greatest distance between any two points is the distance between the first two photons that headed off in opposite directions at the time of the Big Bang.  Those photons still exist, and are still making their lonely trek through the unimaginable black nothingness at close to two hundred thousand miles per second.  So yes, I do believe the universe is that big.  At some point, you can view the positions of those photons more as a variable in some giant computer.  Their distance from everything else is actually pretty much irrelevant, since there is nothing out there for them to interact with.
1094356
It means that we can measure the size of the universe, but if you tried to approach an "edge" of the universe, all you would do would be to extend it. Wherever you go, the universe goes with you, so it is unbounded. You cannot go "outside" the universe.
909934
There is some controversy over that. It is difficult to account for the expansion of the universe if it doesn't. At least at the very beginnings of the big bang.
844932
i don't think in terms of the universe being massive compared to the size of galaxies,but minuscule compared to that which is outside the universe, that way there is an endless supply of material on hand.here at the"center of the universe"it's all relative to our thinking everything is so large but since all we can do is theorize about whats out there,why cant we theorize outside the box,way outside the box. where did science get this idea ? i believe that a chaotic set of galaxies brings about an ordered universe that is a single organism of a larger set of chaotic universes,which in turn forms ordered groups of galactic multiverses which is a small component of a megaverse ,and so on
21285
not necessarly but possible if it goes further
784741
The universe may be infinite in size, or it may be of only finite size. Doesn't the universe have to be infinite? It doesn't make any sense that it would be finite, then there would be some end or edge, and what would be beyond that?\n\nStrange as it may seem, the universe could be finite, a finite universe would not have to have any edges or an end, it could 'wraparound'. The universe could be curved. Huh? How could you curve the universe?\n\nAn analogy should help, consider the surface of the Earth. It looks flat and many children and ancient people might assume that it is flat and that it is either infinite or must have an end or edge somewhere.\n\nBut the Earth's surface is curved, it wraps around and closes in on itself. There is only a finite amount of area yet there is no ends or edges. The two-dimensional flat surface of the Earth is wrapped around into a sphere when viewed in three dimensions. If you set out flying westward in a plane, you will wraparound and eventually return to where you started, approaching from the east.\n\nThe universe may be a curved three-dimensional space that wraps around and closes on itself. If you set out in a spacecraft heading one direction, you could eventually return to the same spot from the opposite direction.\n\n \n\nA nice demonstration of the scale of the universe is to start with a view showing our galaxy and then zoom by a factor of ten once per second. Such a demonstration is done at http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/ \n\nClick on this link and view the demo. Use your browser's Back button to return to this page after watching the demo.\n\n\nThe entire universe, or just the visible portion of the universe if its infinite, is roughly 27 billion light-years across. That's 159,000,000,000,000,000,000,000 miles. Our solar system, from the Sun to Pluto, is .00063 light-years across or 3,720,000,000 miles. That makes our solar system 42,700,000,000,000 times smaller than the whole universe.\n\nCan we put that into a more meaningful perspective? If the entire Earth's surface represents the whole universe, the solar system on that scale would be one-millionth of a meter wide, about 1/25,000 of an inch, the size of a single, small bacteria.
1027618
It is quite possible for the universe to be both finite and without a boundary. No wall, but still it doesn't go on forever. Here's a way of visualizing it. Imagine that nomatter which direction you choose, you will eventually get back to your starting point if you go far enough in a 'straight' line. Impossible? Free your mind. It happens in two dimensions on the surface of a sphere. While it currently looks like the universe really is infinite, such three dimensional spheres were models used for finite universes until the data showed they are probably wrong.
229431
What we consider the physical universe is limited by physical laws. The universe that we can comprehend beyond those laws has limits that we can not comprehend. One such limit is the speed of light if matter in the universe exceeds the speed of light relative to our observation point it will pass out of existence as far as we can detect. A black hole is another such limit to our universe, infinite time, distance etc. The Begy concept of gravity(a substatement in the atomic model) describes a big bang which has no beginning and no end, infinite energy. which we can only detect as the force of gravity. Hey theres another limit!
355200
Theoretically, there is such a thing. It is called a tachyon, and has the ability to travel at beyond light speed. However, the physics of such a particle are very hard to figure out, because of the sheer mechanics of such a feat. \n\nAnd, as one of the guys above me said, galaxies that are beyond 13 billion miles away from us are travelling away from us at light speed and greater; this is why we cannot see them. The only way we know they're out there is because we think the universe is infinite, and that it is much the same throughout as it is here.
264754
Think of the universe as a giant bubble. Outside the bubble is nothing. nothing exists. no space. no time. Even though there is an edge to the universe, you cant reach it. If you started at the earth and went in a straight line. you would eventually come back to the earth. Also, we are not the only universe. there are other bubles. too. they are in the same nothing as ours. But you could not travel to other universes.
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.
313404
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.
1044184
Your question assumes the first part is correct.  It is just an assumption. We can define the universe as everything that exists - therefore precluding anything bigger. In other words, the universe is it - all there is. It includes all matter, energy, forms, spirits if you will, everything we can conceive of and everything we cannot conceive of.  Okay?
918239
where ?\nin outer space. there is room enough.\nor am I wrong ?
645859
No practical method has been found yet (unless I missed a memo somewhere), though it's still a very tantalizing possibility.  We'll have to be careful when the time comes near, however.  There's a chance that we could start a second Big Bang and pop another Universe into existence inside our own.  A rather significant environmental impact.\n\nMeanwhile, have a read of Arthur C. Clarke's novel "Songs of Distant Earth," where he talks about vacuum energy and such trivial concepts as stopping the expansion of the Universe.
363300
a lot more, actually there is a whole "landscape" full of universes, with probability's of more then 10x500 that's 500 decimals, the cosmological constant currently predicts that the universe is not heading to the "big crunch", but rather it will continue expanding unless the cosmological constant changes which is very unlikely to happen.\n\na great book to read on that subject is "the cosmic landscape" by Leonard Susskind, this book is mind boggling.