90% of the universal mass seems to be gone. Could it not exist at all?
97653
Actually the "missing mass" percentage is more like 96%. Science is pretty sure that there has to be something else present in the universe to cause the motions and velocities of large-scale structures like galaxies and galactic clusters. Based on recent research and analyses, it now looks like the universe is composed of about 4% "regular" matter, stuff we can see or infer is present, 23% "dark" matter that we can't as yet see or detect, and 73% "dark energy", the mysterious force(s) that is causing the universe's expansion rate to increase.
574838
It can and does. Most of the universe is empty space, with no matter or energy in it. Unless you mean all of space, as a whole. In which case, it doesn't exist devoid of matter and energy, and it is highly unlikely that it ever would. (Almost impossible, but no one really knows enough to be able to say that, for certain.) But seeing as how space is simply nothingness, I don't see why it couldn't.
1048159
I'll assume you mean the beginning of the universe, not the beginning of the earth. The earth formed about 8 billion years after the universe did, so there was plenty of matter at that point.\n\nYou are wrong in saying that matter cannot come from nothing. There are always 'vacuum fluctuations' where matter and anti-matter are spontaneously forming and disappearing. This is a measured effect and is important in our understanding of electromagnetism.\n\nOn theory (and I want to emphasize that it is a theory) is that the vacuum with *nothing* in it is at a higher energy than one with *something* in it. The difference in energy is quite large and when the vacuum decayed, it allowed the formation of a *lot* of matter and anti-matter. Because of an asymmetry between matter and anti-matter, when thing recombined, there was a small amount of matter left over. This is the matter we see around us.\n\nAnother theory is that there was another 'universe' before ours that experiences a 'Big Crunch' and collapsed. There was then a type of bounce which formed our current universe. So there would have eben all the matter and energy of that previous universe to work from. This theory has recently been given more credence because of a calculation made with quantum loop gravity ( a proposed theory of quantum gravity).
202172
It hasn't been observed, if that's what you mean by proven, but it is a widely accepted idea because the theoretical underpinnings are very solid.  I don't think anyone contests the idea much these days.  If we're lucky, when the LHC at CERN comes on line in late 2007, we may be able to make microsingularities and watch them evaporate, giving direct proof of Hawking radiation.
1106396
err the big bang was not really a a collision of matter. All mass and energy in the universe existed at a sigularity, or a dimensionless point. The Big Bang simply expanded and inflated it.
129944
Don't worry, this will never happen. The "gravity" of the earth is actually caused by attraction between two objects of significant mass.  Were the gravitational force of the earth to vanish, that would mean that the earth itself had vanished.  It would also mean that you would be in free-fall, expereincing what might appear to be weightlessness.  not that this would matter considering that you would be in the void of space and would be dead.
1000581
It is not a viable question, everything is crushed into a singularity, it is like a constricting consuming star, it may well produce light but that light is in turn sucked back in. Pushing aside the idea that you would cease to exist as your atoms are brokent down and crushed to miniscule size you would see nothing as not light escapes. And barring that obstacle and somehow light did you would probably see a swirling speck that is drawing in everything but not getting any bigger, feel an enourmous pull and see light being drawn in, broken down and consumed along with anything else.
346473
From a cosmological point of view - there used to be 3 standard theories about the fate of the universe, all dependant on the total mass of the universe:\n\na) High total mass - eventually the gravitational mass of the universe will halt and reverse the expansion of the universe.  This would naturally end in the universe collapsing in on itself - this is known as the Big Crunch.\n\nb) "Just-right" total mass - the mass of the universe is just enough to halt the expansion of the universe, but not enough to draw it back in.  This requires a very specific total mass of the universe as as such is unlikely to happen.\n\nThe 2 above theories have been more-or-less completely ruled out in recent year as not only is the expansion of the universe not slowing down, but is in fact accelerating.  Which leads us to:\n\nc) low total mass / unexplained acceleration of matter - The universe will continue to expanded, its constituent parts getting further and further away from each other.  \n\nEventually, there are not enough concentrations of hydrogen around , and no new nebulas are formed.  This means no more stars, and no more heat sources. This is usually referred to  as the "Big Freeze" scenario.\n\nCheck the below page for other possibilities.
904747
Its origins and nature are still open to postulation. But it is an attractive force only between any two masses and Newton concluded in his uneiversal laws of gravitation that the attractive force (F) was proportional to the masses interacting(M1 and M2) and inversely proportional to the square of their distance apart (r)\n\nie F α M1*M2/d²\nwhence \n\nF = G*M1*M2/r² \nwhere G is the universal gravitation constant\nG ≈ 6.6742 x 10^(-11) Nm²/kg²
163886
It theory it would destroy the body... and the rest of the universe. In relaity it's simply impossible.\n\nAny object travelling at lightspeed has infinite mass. That in itself isn't a problem, except that to decelerate a mass in any way you need to apply equivalent energy in the opposite direction to overcome inertia. An infinite mass has infinite iniertia. So to decelerate and mass will need to apply infinite energy.\n\nI've read some really good speculation on what would happen when a FTL mas hits something. It seems to come down to two camps.\n\nThe first camp says that the bullet can't be slowed down because has infinite iniertia and thus will always continue on its way. But the body it strikes has to absorb some energy from somehwere if it is to remain stationary. Through some methaemetcial gobbledegook it's apparently possible to arrive at a solution that the bullet will pick up the body and accelerate it to the same speed to avoid the problem. That means that the clothes are also accelerated, and the ground under its feet etc. Instantly the whole universe attempts to accelerate to lightspeed, which means that evertyhing is at the same energy level: infinite. Equal energy levels,  no energy transfer possible, instaneous heat death. By by universe. We all cease to exist.\n\nThe other school suggests that the bullet can't help but be decelerated. Yes it has infinite intertia, but the body has some iniertia too, so any interaction has to result in some energy loss from the bullet. Some energy loss/infinite kinetic energy = infinite energy. The interaction requires more energy than the noverse contains. Once again, instant heat death.\n\nThe trouble is that massive objects can only achieve lightspeed in theory, so we can only speculate on what it would be like. But the math says that any attempt to slow it down will require more energy than the universe actually contains one way or the other. It's an impossibility but if it ever could happen the universe couldn't continue to exist, at least not in its current form.\n\nWorrying about what happens to the body is a minor detail. The body will die with the universe.
155835
The problem is to tabulate the total mass of the Universe, a realy BIG problem.  There may be a lot of undetected dark matter in the universe that would shift calculations of the Gravitational Constant that will determine the fate of the Universe.  It is like trying to count the mushrooms in a totally blacked out cellar while blindfolded, or even much harder.  Progress is being made as the limits of the Universe are being explored by every means possible, especially by use of the human brain.
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.
3627
one estimate is about 10^52 kg, that is:\n\n\n100000000000000000000\n 00000000000000000000\n 00000000000000000000\n 000000000000 \nkilograms\n\nWithout about 90% being the "invisible" missing mass stuff.
187216
Plenty of physicists today still believe that the elusive Theory of Everything (or Grand Unified Theory) is something that does exist, however, I don't think very many people are actually actively looking for it. The biggest problem at the moment in regards to some sort of unified theory, is that there is no rectifying quantum theory with general relativity (as which would be needed to describe black holes, for example).\n\nBut yeah, I think that it is possible, considering that all evidence suggests that we are rational beings in a rational world. I'd like to find it myself!\n\nAs for whether Einstein would have been able to prove it, I really doubt that. He spent the final years of his life trying to disprove the inherent uncertainty in the universe that quantum theory requires. From what I've been taught, most people think that his talents were wasted on this vain effort; they are happy to accept the Copenhagen interpretation, and don't much care if, upon deeper examination, it does result in fundamental order and certainty. The mathematics work, and it has been proven... there's no problem with it unless you don't like the philosophical implications.
557686
Ok...we don't know how big the entire universe is. It may well be infinite, which, assuming it is homogeneous, would mean that it has infinite mass. At any rate, physicists currently think it is "much larger" than the observable universe. How much larger? I don't think that they have any evidence. But let's assume that we can see 1% of all visible space. This would make the mass of the universe = 100 * 3 * 10^52 kg, or 3 * 10^55 kg.
339011
Qunatum uncertainty says that you can never be certain that space is empty at Planck distances, therefore on those scales there is always some matter-energy in the form of virtual photon / antiphoton pairs that suddenly come into existence and then annilihate one another.  This suggests to me that empty space cannot exist on its own unless there is something in it.  Ultimately, we can spin whatever theories we want and debate forever which ones we prefer - but unless someone can design practical experimental methods, then the arm chair physics will not resolve very much.
1082883
Unless you are referring to matter, e.g, atoms, being converted into pure energy, the only way any form of matter can completely disappear is if it is what is known as a virtual particle produced from vacuum fluctuations in space, which immediately disappears without any affect on the surrounding matter or space