What is behind the sky and how big is the universe?
150200
The universe is as big as Gods pinky.  And smaller then his thumb.
476125
Huge.\n\nThere is an edge to what we are able to see and could ever possibly see in the universe. Light travels at 300,000 kilometers per second. That's top speed in this universe—nothing can go faster—but it's relatively slow compared to the distances to be traveled. The nearest big galaxy to our Milky Way, the Andromeda galaxy, is two million light-years away. The most distant galaxies we can now see are 10 or 12 billion light-years away. We could never see a galaxy that is farther away in light travel time than the universe is old—an estimated 14 billion or so years. Thus, we are surrounded by a "horizon" that we cannot look beyond—a horizon set by the distance that light can travel over the age of the universe. \n\nThis horizon describes the visible universe—a region some 28 billion light years in diameter. But what are the horizons of a civilization that inhabits the most distant galaxies we see? And what about galaxies at the limits of their vision? There is every reason to think that the universe extends a long way beyond the part of the universe we can see. In fact, a variety of observations suggest that our visible patch may be a small fraction—maybe an infinitely small fraction—of the whole universe. \n\nThis view of the universe fits with the currently popular idea that the universe began with a vast expansion of size. The idea describes a kind of undirected energy present in the vacuum of space, called scalar fields, that somehow got channeled into a process called "inflation." By conservative estimates, the universe expanded so much during this period that something the size of an atom inflated to the size of a galaxy. \n\nIf this grand idea is correct, then the universe is larger than we ever could have imagined.\n\netc...
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.
650212
The universe encloses all the stars and galaxies...so the answer is...we would see the universe. By the way, if I was that far out there and looking back, I'd be worried about what was sneaking up behind me.
332036
the radius of the observable universe is about 46 billion lightyears.  currently, the expansion of the universe is accelerating not decelerating.  any observers existing in the very distant future will only be able to see bodies within the galaxy that is the result of the merger of the milky way and andromeda.\n\nmaybe these sites will help.\nhttp://map.gsfc.nasa.gov/m_uni.html\nhttp://www.astro.ucla.edu/~wright/cosmo_01.htm\nhttp://universeadventure.org/\nhttp://www-supernova.lbl.gov/\n\ni have something else for you to think about.  the universe is 13.7 billion years old yet has a radius of 46 billion lightyears.
659476
"...What are the dimensions (length, width, and height or thickness) of the physical universe (in light years)?..."\nThe universe can't be measured in terms of length, width, and height. Such parameters require some reference point from which measurements can be made, along with some distant boundary where the measurement would end. You simply can't do that with the universe because the universe is isotropic, meaning it's the same in all directions from any observing point. From Earth we can look outward in any direction and 'see' about 13.7-billion light years. From Earth that represents a boundary. Here comes the tricky part: if some alien in a galaxy 13.7-billion light years away from Earth looked outward in all directions (including back towards Earth) they'd 'see' a universe that appeared to be 13.7-billion light years in scope. In other words, the universe has no boundary. To have one it would have to be inside some "thing" else, and there's absolutely no evidence that such is the case.\n\nTo confuse the issue even more, if we had the ultimate telescope with limitless viewing power we still will never be able to see into the universe beyond a certain range. That's because at almost the same instant of the Big Bang the universe briefly expanded faster than light (this doesn't violate relativity because it was the space of the universe that did the expanding). In our 'normal' universe the speed of light is the speed limit which prevents us from ever seeing any of that inflation because it's moving away faster than the speed of light.\n-----------------------------------------------------------\n"...I've read that the universe is thought to be "saddle shaped..."\nMore recent observations point more towards the universe being geometrically "flat." This simply means that the universe appears to be infinite, that its space will expand forever while cooling more and more over the eons.\n------------------------------------------------------------\n"...What does it mean for example, to say that the universe is expanding at a rate of 70 kilometers per second per (x number of light years)?..."\nYou've described the so-called Hubble Constant. (70 km/sec/Mpc) It means if galaxy 'A' is 1 Mpc (1-million ly) away from us it's recessional velocity will be 70 km/sec. If galaxy 'B' is 2 Mpc away then it's velocity will be 140 km/sec It's important to keep in mind though that it's space that's expanding like that, not the galaxies moving THROUGH space; they just get carried along.\n------------------------------------------------------------\n"...I was not able to find a rate of acceleration of expansion..."\nI've been looking for a figure too. So far the only thing I've come up with is -3.15^36 /sec/sec  Darned if I know what the units of measurement are though. Maybe someone else on Yahoo can help us out with that.
319855
The visible universe is supposedly that size because we can see the light from the beginning and therfore base the size on how far light has travelled in the time; However, the universe is not actually that size, since there are areas beyond the Event Horizon which light has not come from yet, and thus the universe is larger than that estimate.\n\n More to answer your point, the universe is expanding at its limits, but as it does so it creates teh space that we as three-dimensional beings can move in, like a dot on the surface of a balloon; If the dot could move anywhere on the surface, it could move all over the balloon, but never cover all of it as it expands. In the same way, the univrese is finite in size, but unbounded in dimension and therefore to practiacl purposes probably infinite.\n\n It's a hard concept and many people have trouble with it.:)
18752
it basically says that there are these giant cosmic strings that stretch an infinite distance and they are very dense (as in they're so thin that they are not visible, yet a millimeter would weigh tons and tons) and their huge mass warps space-time and they help to make up the universe as we know it. there are also small vibrating strings on the sub atomic level that make up the smallest divisions of matter. String theory also describes 11 dimentions.  If you're interested in it, read "the elegant universe" by Brian Greene, it explains it a lot better than i can here.
126355
In the sense of a comoving distance scaled to the current conditions, the universe is only 13.7 billion light years in radius because the universe is only 13.7 billion years old. However, space itself may expand faster than c making the physical size associated with this much larger. This occurs when space expands while a photon in transit, and the photon may traverse a proper distance which is greater than the Hubble distance, or the traditionally defined edge of the observable universe.\n\nThere is some disagreement as to exactly how large the observable universe in proper distance is: a study of the cosmic microwave background radiation by WMAP in May 2004 states the universe is at least 78 billion light years in radius, yet the March 2005 issue of Scientific American cites a figure of 46 billion lys in every direction. The ambiguity in size is dependent on the detailed models of the Hubble Law, especially the nonlinear nature of dark energy component of the universe which is causing the expansion of the universe to accelerate.\n\nIn practice we can only observe objects as far as the surface of last scattering 300,000 years after the big bang when the universe had cooled sufficiently to permit electrons to bind to atomic nuclei, which brought a halt to the Compton scattering of ambient photons.
561415
physically the universe has no limits . but still it is expanding with enormous speed . you can go to this link : http://en.wikipedia.org/wiki/Space and find out whatever you need about space . good luck
423943
The universe is basically everything.  The visible universe is the part of the universe that is known to us, it is the farthest we can see and, hence, the farthest we can study.  There may be more beyond this but it is kind of silly for us to worry much about it at this point because it is beyond our reach.\n\nVacuum (I'm assuming that's what you were typing), is supposed to be the complete lack of matter.  If you say that there is a vacuum inside a box then there should be no atoms inside the box.  We say that space is a vacuum but this is really a generalization.  Space is not completely empty but things thin-out the further you get away from the Earth, our sun, our galaxy...\n\nI'm not sure how one creates a real vacuum.  No one really knows how our universe came into existence but we have a very good guess that it started with the Big Bang.  There is some evidence to support this.\n\nHere are two websites that describe it better than I could if you are interested.\n\nhttp://en.wikipedia.org/wiki/Big_Bang\n\nhttp://liftoff.msfc.nasa.gov/academy/universe/b_bang.html
459525
Physical cosmology is the branch of physics and astrophysics that deals with the study of the physical origins of the Universe (the Cosmos) and the nature of the Universe on its very largest scales.
334137
the universe is finite yet has no boundaries. it may be something like the two dimensional surface of a sphere.  nothing inside or outside the sphere exists for the two dimensional surface.  nothing exists outside the universe in this model.
300537
There is disagreement over whether the universe is indeed finite or infinite in spatial extent and volume. Many astronomers and cosmologists believe the universe is infinite due to recent findings in NASA's WMAP project supporting a flat (therefore infinite) universe\n\nHowever, 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, due to the ever increasing rate at which the universe has been expanding; it is estimated to be about 78 billion light years (7.8 × 1010 light years, or 7.4 × 1026 m). 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\nBoth 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.
499544
There are numerous problems with your assertion: you measure the universe's size using the farthest object viewed from earth (13.7 billion ly).  Then you assume (from your equations) that earth is at the center of the universe (a somewhat egotistical idea), also, you forget to measure in the opposite direction (galaxies are visible at 180 degrees of the one observed to be 13.7 billion ly from here). Add to all these your interesting equivalent of the speed of light...apparently you believe the speed of light to be somewhere around 34.2 meters per second (a mere 226.4 times slower than the space shuttle).  If you are going to try to figure out the size of the universe, do a little more research and brush up on your math...for example: \n\n"From new data collected from a space probe examining the Cosmic Background Radiation, astronomers estimate the universe is at least 156 billion light-years wide. Actually, it’s long been known that the universe was a lot wider than 27.4 billion light-years; this latest research tells us how much wider.\n\nAccording to researchers writing in the journal Physics Review Letters, the universe must have expanded much faster than light in its early stage." *\n\nSo take into account that one light year is 9,467,280,000,000 km ** and you get...\n\n1.476895680 x 10^24 km\n\nthat's 1 octillion, 476 septillion, 895 sextillion, 680 quintillion kilometers wide (or 1 quadrilliard, 476 quadrillion, 895 trilliard, 680 trillion kilometers wide for those following the European system of counting)...and that disregards the continued expansion since the observations.\n\nOf course there are also quite a few scientists who affirm that the universe is infinite, so, in the end, nobody really knows.
909543
If the Andromeda Galaxy is 2.5 million light years away and it's the only galaxy on Earth to be seen by the naked eye, it leaves us to wonder how far it really is.\n\nPersonally, I googled it. I couldn't find a thing relating to the blank nothingness further than the universe.\nI only looked a little bit, but there are very few educational guesses on the Internet.\n\nMaybe you should try. Googling that is. Maybe it's you who'll find the right words to search it in.  \nThe words stumped me so the was probably my problem.\n\nGood luck on finding the answer!\n-Marissa
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.)