Why is the universe so big???
828819
Thats a question that physics is still trying to answer.  \nThere are 3 types of theories on how big the universe is and the shape of it.  It is either flat, meaning it will always be this large and continue forever.  There is the closed ellipse type, meaning the universe started from something, but unfortunatly will end after its reaches its max capacity and starts to shrink again.  There is still the hyperbola theory meaning that the universe started at a finite point and is always expanding.
368430
Okay considering this scientifically (ie not just assuming there is a God) at the moment no one is sure how the big band happened. However the big bang was the start of time as well as space so it is difficult to talk about before. Some scientists believe that the big band was caused by tiny fluctuations of the vacume. Something like the universe can be forever just by never stopping or by time ending much as it began in a 'big crunch'. It is possible that there is something beyond the universe. M-theory suggests that there are many different dimensional universes floating around in a larger dimensional space. All of these are of course theories the point is to try to use these to make observable predictions which will either support or contradict the theory.
1048593
Thank you! Very informative (and correct) information!\nWell, according to Physics, the same vast quantities, dimensions etc., we have to the large scale, we also have to the small scale, going from our size into smaller (cells, moles, atoms, electrons, nuclei, ....)\nFurther, according to my theory, the Universe we described above is the connection between other universes! As a matter of fact, each one of us is a Universe greater that the one we usually talk about! After all, people discover the dimensions, Greeks named 4 of them and we, somehow think we understand them! People understand only what has been named! That is why we can not comprehend the other dimensions, since we have not discover how the Greeks named them!
90108
I don't believe so.  If there is any merit to the Big Bang theory (and there's lots of scientific evidence in support of it), then the universe has a radius of currently about 14 billion light-years, and is expanding.  \n\nThat's pretty big, but it's not infinite.
1186033
There is only one universe, and to say it is expanding actually refers to the fact that the solar systems, galaxies, etc are all spreading apart from one another.  If you believe int he big bang theory, them think of yourself in one VERY slow explosion spreading out from that central core.  \n\nSo I guess to answer your question, it is expanding into itself.
1076114
Odds are that the universe IS teeming with life.  We haven't been to the universe -- it's very big and most of it is too far away.
1151663
Universe in not infinite. It is finite and constantly expanding. Yes there are more galaxies than no. of grains of sands in all beaches of the world. This universe is unimaginably huge!
612456
My Astronomy teacher at college of the redwoods believes it not to be the like a big ball though, it may be in some way like that.  He believes it is more like a blob of water in zero gravity.  It isnt a circle but it has i would say lumps in the ball type figure.  All of this but on a much larger scale.\n\nBy the way the universe is not infinite but it is expanding.  It may be huge but we believe to have found areas that just return no data.  It is about 560 billion light years away from us.  It is illogical to even believe anything physical to be infinate.
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.
1055858
If you've ever wondered how big the universe is, you're not alone. Astronomers have long pondered this, too, and they've had a hard time figuring it out. Now an estimate has been made, and its a whopper.\n\nThe universe is at least 156 billion light-years wide. \n\nIn the new study, researchers examined primordial radiation imprinted on the cosmos. Among their conclusions is that it is less likely that there is some crazy cosmic "hall of mirrors" that would cause one object to be visible in two locations. And they've ruled out the idea that we could peer deep into space and time and see our own planet in its youth.\n\nFirst, let's see why the size is a number you've never heard of before.\n\nStretching reality\n\nThe universe is about 13.7 billion years old. Light reaching us from the earliest known galaxies has been travelling, therefore, for more than 13 billion years. So one might assume that the radius of the universe is 13.7 billion light-years and that the whole shebang is double that, or 27.4 billion light-years wide.\n\nBut the universe has been expanding ever since the beginning of time, when theorists believe it all sprang forth from an infinitely dense point in a Big Bang.\n\n"All the distance covered by the light in the early universe gets increased by the expansion of the universe," explains Neil Cornish, an astrophysicist at Montana State University. "Think of it like compound interest."\n\nNeed a visual? Imagine the universe just a million years after it was born, Cornish suggests. A batch of light travels for a year, covering one light-year. "At that time, the universe was about 1,000 times smaller than it is today," he said. "Thus, that one light-year has now stretched to become 1,000 light-years."\n\nAll the pieces add up to 78 billion-light-years. The light has not traveled that far, but "the starting point of a photon reaching us today after travelling for 13.7 billion years is now 78 billion light-years away," Cornish said. That would be the radius of the universe, and twice that -- 156 billion light-years -- is the diameter. That's based on a view going 90 percent of the way back in time, so it might be slightly larger.\n\n"It can be thought of as a spherical diameter is the usual sense," Cornish added comfortingly.\n\n(You might have heard the universe is almost surely flat, not spherical. The flatness refers to its geometry being "normal," like what is taught in school; two parallel lines can never cross.)
408049
Current estimates for the size of the universe are that it is so large that light from some parts of it that has been traveling towards us since the moment of the Big Bang still hasn't had enough time to reach us.  Furthermore, the universe is expanding rapidly enough that such light will NEVER reach us.  Therefore, no matter how advanced our telescopes become, humans will never be able to see the most remote reaches of space.
40749
Sorry, as Braxton points out, the size to the edge of the observable universe is 78 billion light years due to the expansion of the universe (same source as the other guy used, Wikipedia) There is much debate as to whether or not the universe is infinite, but many scientists believe that the universe is indeed finite in size.\n\nBY THE WAY: I find it comically amusing how two people can cite the same source, yet somehow I'm the wrong one.  Oh well ;)
79119
Our universe has 4 dimensions of space-time, and the domain of these domains is finite.  However, the expansion of that is in a larger dimensional space--meaning more than our four dimensions, with higher dimensions orthogonal to our four.\n\nThink of the 2-D surface of a balloon.  If you were a 2-D being on the surface on that balloon, you'd have no concept of the 3-D space inside and outside the balloon--your entire existence wouldbe contained on that 2-D surface.  But if the balloon inflated, you 2-D reality would grow in the context of the larger 3-D reality which was beyond you.
249324
Of course the size of this galaxy and universe are beyond human undestanding, I know this scientist did a math formula where he put the very least possiblities of life and the number was still huge.\nEx, he did like in one galaxy there is only X planet where there is water and only X springs life and only X becomes civilized, and in the end he figurd there tons of life out there!
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 .
1165431
From the physics point of view, our universe thus far is approximately 15 billion light years and expanding every second. Light year is the distance that light with the speed of nearly 300,000 Km/s travels in one year. This distance equals 9, 500, 000, 000, 000 Km (that light travels each year). Now, imagine how big our universe is!!\n\nAbout the second part, The space-time (space and time are inseparable) make our universe. They are both dynamic and the  fact that universe expands means both the space and the time expand. Now, in what do the space and time and our universe expand? This fact is not like other daily facts in our life, it is not possible to assign a place for space-time so that our universe expand in it. We cannot say there is something outside our universe because it is meaningless. These concepts are complex and require in-depth studies and deliberating.\n\nI hope these would be a little helpful...
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.