how big is the universe?
400480
Olliehunt has the right idea, but the expansion of the Universe during the first second (although probably less than that), was so incredibly fast, millions and millions of times faster than the speed of light, that the final figure he came up with is much smaller than what could be the actual size of the Universe.\n\nThe simple answer is, we don't know.  It's vast!
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.
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.
1048724
Before we can address that question, we must first define universe. \n\nThe word universe denotes all space and everything (matter, energy) contained within it. The prefix uni means one. The root verse means word, carnate message, meaningful substance, matter. Questions regarding our universe persist today. Does it have a beginning and end, or does it go on forever and ever? Is it linear or curved? If it has limits of length or curvature, then what lies beyond the Universe? If something lies beyond the Universe, then can’t we accurately call that the Universe?\n\nSome lay people and some scientists conceive of the universe as infinite space. Others define the universe as finite, or limited (perhaps curved), space. Still others incorporate the elements of matter and/or energy into their definition of the universe, as opposed to the space beyond matter and energy.\n\nGiven these concepts of our universe, some scientists conclude that the “totality of space could be infinite. Shrink an infinite space by an arbitrary amount, and it is still infinite. (Scientific American March 2005).” \n\nAs to the notion that we live in an ever expanding universe, moving away from every other universe on the fabric of space-time, some scientists are careful to point out that “\n\nAndromeda, our nearest large galactic neighbor, is actually moving toward us, not away. Such exceptions arise because Hubble's law describes only the average behavior of galaxies (Scientific American March 2005).”\n\nIn accordance with your supposition that our universe is in another universe, “it has been hypothesized by some scientists that the universe may be part of a system of many other universes, known as the multiverse (http://en.wikipedia.org/wiki/U... Modern astrophysicists talk about multiple "pocket" universes that branch off from one another. Stephen Hawking points out that parallel pocket universes can have no effect on a real observer inside a single pocket, so, according to Hawking, they are theoretical baggage that should be eliminated from cosmology, the study of the origins of the universe.\n\nSome string theories define the universe as a three-dimensional space in an invisible space having more dimensions. This is, in essence, a universe within a universe. Our zone, a “braneworld” could periodically bounce into another parallel braneworld. \n\nThis may create what would appear as a Big Bang from one perspective or a Big Bounce of alternating expanding and contracting universe from another perspective. Such a cataclysmic event is thought to occur 300 billion years from now, resulting in the rearranging and creation of a new universe.\n\nWhich is the end of expanding universe? That may be determined in 300 billion years, when it stops expanding (like a balloon). If any end exists, what will be behind this end? A multiverse void containing other expanding and contracting balloons, referred to as universes, may exist beyond our own.
220701
We don't yet have the technology to answer this question.\n\nEDIT: To dogoutburner: That's the largest in our galaxy. We have no idea the largest in the universe.
923222
The smallest anything can be is called Plank length and it is approximately 1.6 × 10 (to the -35th power) meters.  \nAssuming "we" is the earth, we are very small compared to the size of the universe.  The "volume" of the observable universe is about  1.9 × 10 (to the 33rd power) light years, and the earth has a volume of approximately 8.2 x 10 (to the 12th power) miles, or 4 x 10 (to the -26 power) of a light year.  The universe, then, is about 4.7 x 10 (to the 58th power) times bigger than the earth.
398088
I asked that question to Dr. Brian Greene, author of "The Elegant Universe".  His answer was "the Universe is continually expanding", and therefore, you can't put a size on it.  The Universe, in a sense, CREATES the space it's expanding into.  It is all-encompassing.
533282
earth= 5 billion, sun= 7 billion, sky ie universe= 12 billion\nmoon= 4 billion
472941
There\nIs\nNo\nMap\nOf\nThe\nUniverse.\n\nThe universe is, in theory, an infinite size. Meaning it has no end or beginning, kind of like American Idol or Myspace.
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.
313486
your answer is in \nhttp://en.wikipedia.org/wiki/Big_Bang
78408
The Planck length is the smallest possible length in our universe. 10^-33cm\n\n"Particles" can come into existence in opposite pairs which balance the total energy of the universe at E = 0. Were this not true, the universe would be empty.
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...
657544
Isn't the universe infinite? How can it have a definite radius or circumference if it's infinite?
370961
go to\nhttp://en.wikipedia.org/wiki/Universe
326153
1)"The simple answer is that the observable Universe is about 20 billion light years in diameter. That number is obtained by multiplying how old we think the Universe is by the speed of light."\n2)rate of expansion is not constant throughout the Universe\nit varies with distance\nyou can see the variation with distance in this GRAPH AT\nhttp://archive.ncsa.uiuc.edu/Cyberia/Cosmos/Images/hubble_lg.jpg
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.