how old is the universe, what is it made of, how did it start, what are supernovas, what are black holes?
604912
These astronomical questions require astronomical answers. How to start and how to end?\n\nFact is, our existence is only a very very very very.......... small portion of time to calculate. To find how old, we have yet to discover evidence mainly because we cannot reach outside our very own galaxy to explore. Considering that it will take lightyears to travel the enormosity of time and space boggles all that best is people to come with a reasonable reason that will be hard to disprove. No one can. All can theorise.\n\nSo the universe is so large, it is beyond our perception, beyond our present ability to fully comprehend, and though we are making small progresses with probes and telescopes, it is still too huge and complex to grasp. We can theorise based on understanding of our surrounding and equating everything else to what we know. This is our limitation. \n\nUniverse has been around even before our gaalxy is formed bbillion zillions years ago. The acceptable theory is that a big bang ceated our galaxy and out solar system. Something must happen, and people theorise it must be sudden, that is why the bang. And it just happen like that that our galaxy was formed, and then our solar system. No one can track back and so this is so. Hence, theory is what we can do to try to explain to ourselves.\n\nSupernova is a dying star, giving its last burst of energy befre collapsing. Death of stars is something little understood because it is rare. Stars take million of light years to reach us and so we are watching history when some event occurs. So far, only a few supernova had been documented. And these stars actually died millions years beforehand.\n\nIt is theorised that when a star dies, it collapse into itself, as stars are suppose to be like our sun, all gaseous. It is theorise that the star will collapse into a very dense body with very high gravitational pull that it sucks everything nearby into itself. This is the black hole.. It is theorise that it will be so dense that even light cannot escape. So far possible sighting of black hole has been done by noting the bending of light in the universe, since the black hole cannot be seen \n\nSo, outside our atmosphere, we have theories to try to explain everything we see. We need a reason to justify the things we see in space, rather than accepting that they are there even way before life begins on earth, and that there will be many flawed theories because at this time, it is just beyong our ability to check it out.
725562
The essence of the Big Bang theory is pretty simple:  sometime billions of years ago the universe began;  everything now in the universe was created from energy/matter that was compacted into a really, really small volume/space, and indeed that really, really small volume/space was all there was to the universe at that moment; and since the universe began, it's been expanding.  These are the essential points of the theory.  Over time, we've added new details, such as pinning down the age of the universe to within a few hundred million years (last I heard, we thought it was 13.7 +/- 0.2 billion years old).  And a lot of theoretical and observational work have gone into investigating and refining the theory.\n\nAs to why we think that there was a Big Bang instead of, say, a universe which had always existed or a universe which came into being pretty much fully formed, the main reason and the reason we started thinking there was a Big Bang in the first place is because of very peculiar observations that we can make of distant galaxies.  This observation is that, except for a bunch galaxies which are both nearby and gravitationally bound to our own galaxy, all the galaxies we can see are moving away from both our galaxy and all other galaxies.  Also, the speed with which a galaxy is moving away from us depends directly on how far away from us it is (e.g. galaxies farther away from us are moving away from us faster than galaxies which are closer).  And the reason we first infered a Big Bang from this is that if you imagine running this movement backwards, doing a cosmic rewind if you will, then all the galaxies will be moving back towards each other, and eventually will all find themselves in the same place.\n\nSeveral years after this observation, a key predicition of the Big Bang theory was verified.  When the universe was young, it was also really hot and so for a time would have given off light all its own (I'm simplifying things a bit, but these are the essential facts as we know them).  It was predicted that some of this light should still be around.  And, lo and behold, at the very same time that people were making this prediction and beginning to think of looking for it, practically right down the road some experimentalists stumbled upon it accidentally.\n\nSo, in short and hopefully simple words, that's what the Big Bang is and why we think it happened.
854866
Everything we know about, everything we can see, behaves as if 13.7 billion years ago it was a dense, hot plasma that has been expanding and cooling ever since.  That's the Big Bang theory, and there is a tremendous amount of overlapping, detailed evidence to show that it's correct.  The Big Bang theory being wrong is about as likely, and makes about as much sense, as the idea that a Sun-centered solar system is wrong.  Essentially all of modern astronomy depends on the Big Bang to make sense.  The main observations are:\n\n1) The redshift of more distant galaxies is larger than that of nearby galaxies.\n\n2) Quasars and radio sources are seen to evolve.  There were many quasars in the past, now there are almost none.\n\n3) The amounts of the light elements Deuterium and Hydrogen make sense in the context of neucleosynthesis in the Big Bang.\n\n4) The Cosmic Microwave Backround Radiation is as predicted by the Big Bang theory, both in magnitude and in the details of its anisotropy in amplitude and polarization.\n\n5) All stars and galaxies evolve as if that evolution were set into motion by the Big Bang.\n\n\nYour notion of mirages and crests makes no sense in the context of modern physics.  We do see some warpage of space, particularly gravitational lensing by clusters of galaxies, but the Cosmic Microwave Background is most certainly only 400,000 lightyears from our event horizon.\n\nMany current versions of the Big Bang involve a Universe that exists eternally in both the past and future.  Our Big Bang was not necessarily the beginning of the Universe.
664516
NASA's Wilkinson Microwave Anisotropy Probe (WMAP) project estimates the age of the universe to be:\n\n(13.7 ± 0.2) × 109 years. \nThat is, the universe is about 13.7 billion years old, with an uncertainty of 200 million years. However, this age is based on the assumption that the project's underlying model is correct; other methods of estimating the age of the universe could give different ages.
1179225
Good question.\n\nIn short... there's no way to really know how the Universe was created.  Some look towards scientific research to explain our origins while many others trust in their faith as the answer. For now, we can only speculate.
2448
As you yourself suggested in an earlier question, "our" universe is finite, though there may be an unlimited amount of "bubble" universes out there, which we could not begin to have any specific knowledge of...\nEinstein's theory of relativity proved that time was a property of matter, and as matter expands at the speed of light into the omni-directional void, then whatever matter overtakes, there time also exists. In the void, there is no time. The edge of the universe, is where time began, but only for "our" universe...\nOur universe is roughly 20 Billion years old, our earth 4.6 Billion years...\n[From my 7th grade Science class lesson]\nBest question asked: Does the universe have an end?\nMy answer: Who knows!
44714
Universe is ONE and it is ever expanding.\n\nThere are many solar systems like ours in our Galaxy. There are billions of galaxies in the universe.\n\nIf you are interested to know more, check the site http://www.space.com site.
533024
Is our universe in another universe?\n  \nBefore 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 “\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/Universe).” 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.  This 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\nIs our universe inside another universe?  Well, apparently the Men in Black had it right.  Our universe seems to be inside of something else, another universe, called the multiverse.\n\nSteve\n:-D
252532
A black hole is a super dense hole in space with an extremely powerful gravitational pull (not even light can escape).  The 12 months come from the ancient Romans, and to the best of my knowledge aren't related to constellations.  Life on Earth evolved from a "chemical soup" of elements.  These elements cam together to form amino acids, which formed proteins, which over billions of year multiplied and evolved into the 10 million + species on earth today.
268021
According to current estimates, roughly 400,000 years.  This is what we can tell from the data from WMAP, which was launched to measure the microwave background radiation.  It is this radiation that is the leftover glow from when light decoupled from matter, which is the point at which the universe would have "turned black".
280906
Supposedly the universe is estimated to be about 13.6 billion years old.  I think I read that on Wikipedia, though, so you never know...\n\nThat said, I really have so little idea what is out there or what conditions are necessary for life to arise that I don't know which theory is more plausible.  How flexible are the conditions that lead to the formation of primative cells on Earth?  Can there be life based on an entirely different set of molecules?  An entirely different set of elements (i.e. not carbon based)?  How many other planets have chemical compositions and climates like Earth?  Did life even originate on Earth? (I've heard the theory that primative cells could have originated on another planet and been brought here on an asteroid).  Could primative cells have left Earth on some sort of asteroid and taken up residence elsewhere?\n\nI'd like to think there's other life out there, just because it makes things more interesting.  Until I have reason to believe otherwise, I'll assume there is.
1153548
It is a theory that the universe started from a "big bang."  This is considered by scientists as the earliest recorded history of the universe.  It is believed that the entire universe was so dense it was possible that it could have been the size of a planet or smaller.  All that density was too much and it exploded.  Everything back then was hydrogen.  The hydrogen formed into stars.  The stars created other elements because of the neclear reactions breaking up the hydrogen and connecting it together.  This led to planets.  Unfortionatly I would say there is too much info to share everything.  Try reading :\n"A Short History of the Universe"\nI did before I went into seminary.
205236
No one anywhere has the answer to your question, or even if there was any "thing" before the Big Bang. The religious crackpot fundamnetalists certainly don't have the answer! By definition, the universe is everything there ever was, is now, or ever will be. At the instant of the Big Bang, all space-time and energy that will ever exist was created.\n\nGod is spelled B-I-G B-A-N-G\nPBrax@netscape.com
765931
When?\n\nThere are at least 3 ways that the age of the Universe can be estimated. \n\n    * The age of the chemical elements.\n    * The age of the oldest star clusters.\n    * The age of the oldest white dwarf stars. \n\nThe age of the Universe can also be estimated from a cosmological model based on the Hubble constant and the densities of matter and dark energy. This model-based age is currently 13.7 +/- 0.2 billion years. The actual age measurements are consistent with the model-based age which increases our confidence in the Big Bang model.\n\nHow?\n\nNo one really know for sure how however by taking in consideration the evidence the closest thing on how our universe was formed is the Big Bang model. \n\n“Our universe began in a hot dense state which began, and still is expanding. In this initial event, all the matter in our universe was created with approximately 80% hydrogen and 20% helium.”\n\nSome will say what about god? The Big Bang, like all science, doesn’t have any implications either for or against God. What it may do, it place constraints on how God did things and these may run contrary to scripture.
1073548
The Big Bang theory is the most popular one. It is hypothesized that the universe was a collection of dust and other particles forming to one huge mass, until heat and gases formed and pressure from gravity and mass caused it all to erupt in one "big bang" causing everything to project and very high speeds in all directions.\n\nOur world was theorize to have originated through this process. The debris and particles that were projected from the point of origin (now the sun) and locked into its gravitation rotation. The larger mass debris attracted other smaller debris by its gravitational pull to form an even larger mass.\nThis mass growing in size of gases, dust and other particles started to alter by factoring conditions such as distance from the sun and compostion of gases and such. Eventually providing the right conditions and atmosphere to form water which is the basis of life. From that life was made sustainable by the oxygen created by water and plant life... so a billion bunch years later we have our planet earth and the universe we live in surrounded by other planets and stars.\n\nThere are also legends and tales from various religions and cultures that tell the begins of our universe and earth. You'll have to look these up and see.
683506
Wow, what great questions.  Just so you know, we don't know the answer to what was before the big bang.  One idea is that our universe expands, then contracts on itself, over billions of years, and the whole big bang repeats over.  In other words countless universes preceded our own.
277935
A galaxy is a huge gravitationally bound system of stars, interstellar gas and dust, plasma, and (possibly) unseen dark matter. Typical galaxies contain 10 million to one trillion (107 to 1012) stars, all orbiting a common center of gravity. In addition to single stars and a tenuous interstellar medium, most galaxies contain a large number of multiple star systems and star clusters as well as various types of nebulae. Most galaxies are several thousand to several hundred thousand light years in diameter and are usually separated from one another by distances on the order of millions of light years.\n\nAlthough so-called dark matter appears to account around 90% of the mass of most galaxies, the nature of this unseen components is not well understood. There is some evidence that supermassive black holes may exist at the center of many, if not all, galaxies.\n\nIntergalactic space, the space between galaxies, is filled with a tenuous plasma with an average density less than one atom per cubic meter. There are probably more than a hundred billion (1011) galaxies in the visible universe.