Awhile back in the news there was a piece about the expansion of the universe suddenly slowing down dramatically.  Has anyone heard any recent follow ups on this?
137175
Evidence I have seen points to the contrary: that the universe is acutally accelerating in expansion. The majoraty of scholars propose that theory to explain a universe without a singularity, but the evidence favors an accelerating universe.
485682
http://www.sciam.com/print_version.cfm?articleID=0009F0CA-C523-1213-852383414B7F0147\nhttp://universeadventure.org/\nhttp://en.wikipedia.org/wiki/Physical_cosmology\nhttp://www.astro.ucla.edu/~wright/cosmo_01.htm\nhttp://map.gsfc.nasa.gov/m_uni.html\n\nthis is actually a common misconception about the big bang. the universe is not expanding into anything. the universe is four-dimensional, but a two-dimensional version may be something like the surface of a sphere, and it is this surface that is expanding. the universe seems to be finite in size, yet it has no center and no edge. nothing, not even space-time, seems to exist "outside" the universe. the big bang was the entire universe, and everywhere in the universe was once the big bang.\n\nthe earliest, and oldest, radiation we can observe is the cosmic microwave background, and we see it in every direction we look, but the universe was much smaller at that time. the universe had expanded and cooled enuf for electrons and atomic nuclei, about 74 percent hydrogen and 26 percent helium, to combine and form neutral atoms. before this time the universe was much like a heavy fog, but when atoms formed, there were no free electrons to scatter light, and the universe became transparent. today, we see this light stretched to microwave wavelengths by the expansion of space-time.\n\nanything with a cosmological redshift of 1.7 is receding at light-speed, c.  anything with a greater redshift is receding faster than c.  the redshift of the cmb is 1089.  the cmb seems to be at least 78 billion light-years away, but the universe is only 13.7 billion years old.
62642
Universe is not exactly rotating or spinning... it is said to be constantly expanding... and sorry i don't know about the big band
440827
Yes, because the cosmological constant is a specification of a pressure that's constant in each unit volume of empty space.  So it "explains" an expansion over and above the expansion due to the velocity imparted by the Big Bang.  Einstein, after some thought, concluded that the CC = 0; in other words, that the expansion of the universe is due only to the initial kick of the Big Bang and is thus slowing down due to gravity.  But recent observations (of very distant supernovas) indicate that the expansion is not slowing down, but increasing.  This is consistent with a small but positive CC.  Other explanations are possible, though.  For example, there could be a "real" force exerting the outward pressure ("real" as opposed to the very mysterious constant pressure per unit volume); if this is true, such a force couldn't be one of the four known forces of physics, but would have to be a fifth one, and so has been called "quintessence."
201298
This period of "inflation" is one of the big mysteries in cosmology right now.  We have a pretty good idea that something like it happened, but we don't really know how or why.  The timing of the period of inflation fits with the timing of any grand unified theory breaking down, so it may be a result of a symetry breaking of the universe.\n\nThe theories are getting better, but inflation is still one of the toughest topics to try and get a handle on, as the timescales and energies really are at (and even) over the hairy edge of what we know and can comfortably call physics.
510917
The way to measure it is to measure the redshift of galaxies at different distances. Are they starting to slow down, or not? But like was said above, I'm not going to worry about it. Not that cosmology isn't a fun thing to study, but as far as applications it's just about there with Abstract Art. I would say let's concentrate on applied physics, earth and solar science first, develop some new technologies, maybe colonize Mars, some other solar systems, or a good fraction of the galaxy and then we can worry about the fate of the universe when we have more tools, power and understanding to explore or do something about it. It's noble and admirable, but might be like a caveman pondering the lifespan of the sun - that large bright circle that goes around the flat earth. Occasionally skipping ahead is rewarded - most times it's a shot in the dark.
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It doesn't make sense that "everything contained in [the universe] is imploding in on itself". First, no one has the slightest clue as to what exists external to the universe. There's plenty of speculation, but there exists no observations that would point us in the right direction. The universe may indeed implode in itself if it is not expanding fast enough to resist the gravitational attraction of all the mass in the universe. Whether or not it is expanding fast enough is an important and open question in cosmology as well as philosophy.
269210
You misunderstand the Big Bang theory. The universe did not start from a big ball of matter. For the first 10-34 seconds we simply don't have the physcis figured out as to what happened. There are many conjectures, though.\n\nThe first difficulty is that General Relativity predicts something called a singularity at the Big Bang. A singularity is something like what you see at the north pole. There is no 'north of the north pole' simply because the coordinate system can't be extended that way. Under General Relativity, there is no 'before the Big Bang' because thw time coordinate cannot be extended past that point. Remember that time itself is part of the structure of the universe, so time began when the universe did (in this view).\n\nAnother view is obtained through quantum mechanics. We know that modern vacuums are never completely empty. They are a blur of particles apperaring and disappearing all the time. The state of having absolutely nothing is actually a very high energy state. When that state decayed into a lower energy state, that provided the energy that subsequently became the matter we see around us. In this scenario, the singularity predicted by relativity is blurred out by the quantum effects, but the net result is that all the matter literally came out of a vacuum. This is possible without violating conservation of energy because the vacuum state 'befroe the Big Bang' had a higher energy than all the matter we see around us.\n\nAnother possibility is a 'bouncing universe' where the universe goes through cycles of collapse and expansion. The collapse before the current cycle provided the energy for the current one. There are modifications to this where 'universes' bud off of the vacuums of other ones.\n\nAll of this is highly speculative. However, we do know that a Big Bang is how things got started about 13.7 billion years ago. We see the afterglow of the hot, dense time at the beginning all around us in the cosmic microwave background radiation (CBE).
350661
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.
157577
1 and 3 cant be answered other than by speculation\n\n2-According to current theory, the first physically distinct period in the Universe lasted from "time zero" (the Big Bang itself) to 10-43 second later, when the universe was about 100 million trillion times smaller than a proton and had a temperature of 1034 K. During this so-called Planck era, quantum gravitational effects dominated and there was no distinction between (what would later be) the four fundamental forces of nature – gravity, electromagnetism, the strong force, and the weak force. Gravity was the first to split away, at the end of the Planck era, which marks the earliest point at which present science has any real understanding. Physicists have successfully developed a theory that unifies the strong, weak, and electromagnetic forces, called the Grand Unified Theory (GUT). The GUT era lasted until about 10-38 second after the Big Bang, at which point the strong force broke away from the others, releasing, in the process, a vast amount of energy that, it is believed, caused the Universe to expand at an extraordinary rate. In the brief ensuing interval of so-called inflation, the Universe grew by a factor of 1035 (100 billion trillion trillion) in 10-32 seconds, from being unimaginably smaller than a subatomic particle to about the size of a grapefruit.\n\nPostulating this burst of exponential growth helps remove two major problems in cosmology: the horizon problem and the flatness problem. The horizon problem is to explain how the cosmic microwave background – a kind of residual glow of the Big Bang from all parts of the sky – is very nearly isotropic despite the fact that the observable universe isn't yet old enough for light, or any other kind of signal, to have traveled from one side of it to the other. The flatness problem is to explain why space, on a cosmic scale, seems to be almost exactly flat, leaving the universe effectively teetering on a knife-edge between eternal expansion and eventual collapse. Both near-isotropy and near-flatness follow directly from the inflationary scenario.\n\n\nElectroweak Era (10-38 to 10-10 second)\n\nAt the end of inflationary epoch, the so-called vacuum energy of space underwent a phase transition (similar to when water vapor in the atmosphere condenses as water droplets in a cloud) suddenly giving rise to a seething soup of elementary particles, including photons, gluons, and quarks. At the same time, the expansion of the universe dramatically slowed to the "normal" rate governed by the Hubble law. At about 10-10 seconds, the electroweak force separated into the electromagnetic and weak forces, establishing a universe in which the physical laws and the four distinct forces of nature were as we now experience them.\n\n\nParticle Era (10-10 to 1 second)\n\nThe biggest chunks of matter, as the Universe ended its first trillionth of a second or so, were individual quarks and their antiparticles, antiquarks – the underlying particles out of which future atoms, asteroids, and astronomers would be made. As time went on, quarks and anti-quarks annihilated each other. However, either because of a slight asymmetry in the behavior of the particles or a slight initial excess of particles over antiparticles, the mutual destruction ended with a surplus of quarks. Only because of this (relatively minor) discrepancy do stars, planets, and human beings exist today.\n\nBetween 10-6 and 10-5 second after the beginning of the Universe, when the ambient cosmic temperature had fallen to a balmy 1015 K, quarks began to combine to form a variety of hadrons. All of the short-lived hadrons quickly decayed leaving only the familiar protons and neutrons of which the nuclei of atoms-to-come would be made. This hadron era was followed by the lepton era, during which most of the matter in the Universe consisted of leptons and their antiparticles. The lepton era drew to a close when the majority of leptons and antilepton
180560
Very good.  You are close to the truth.\n\nSpace alternately expands and contracts over a two billion year cycle.\n\nWe are now nearing the end of the expansionary phase.  So all the scientists on primitive planets hypothesize a big bang and talk about red shift.\n\nIn the following phase, scientists on other primitive planets will hypotehsize a fiery, incandescent end in the middle of everything and talk a lot about blue shifts.\n\nThe reasons for this have to do with the benefits of dynamic equilibrium.  Static would not work.  Apparently God already knows about this, but so do some physicists.\n\nSoem Dutch guy named DeSitter was also close, I have heard.
8043
Quintessence was discovered by two groups which looked at distant supernova. By seeing how bright the supernova were they were able to estimate how far away they were. This was used to plot the relationship between distance and redshift that can be used to show how fast the universe is expanding.\n\nWhat they found instead, was that the universe is accelerating. That is, the rate and which the universe is expanding today is more than it was a billion years ago, and  in a billion years from today the rate of expansion will be even faster.\n\nThe name "quintessense" is used for various models of the vaccum energy which drive the acceleration of the rate of expansion. The term was chosen because it sound nice and mysterious, it has no connection with any Earth-Fire thing. They could have called it "Peanut Butter" and nothing would have changed in the mathematics - which is what counts.\n\nIf you're interested in science, like it sounds you are, I would strongly recommend reading more about it, and just enjoy the very strangeness of it. Engage with people on message boards. It is extremely difficult to make a major, ground-breaking contribution to physics even with a PhD and research experience. It is basically impossible to do so without one. \n\nI don't mean to be condensending, its just that there were, and still are, a lot of crank theories out there based on a few ideas which may or may not be wrong, but which ignore the VAST amount of experimental data there is about the universe we live in.\n\nYou don't want to fall into the trap of being a crank, or quack. Trust me, I've seen it. (When a post-doc at a big state university.)
663071
Everything started off with The Big Bang. As there is the Big Bang Theory, there is also the big crunch theory if im not wrong. During the Big Bang, the universe is formed and it is expanding. But scientific discovery have showed that the Universe is expanding at a decreasing speed. It will come to a point of time where the Universe will stop expanding and due to the internal gravitational force, the Universe will also start contracting but at a slow rate. It will be really contract really slow at first but the rate of contracing will speed up. Think it as a exponential curve. Yup... Then everything will be suck back to the point of sigularity again and when energy in it becomes unstable it will explode again thus forming the new Universe. But anyway we wouldnt be ard to witness this by then. Not even a million lifetime. HAhahah... So dun worry!
12349
actually they do not care at all if you believe it or not, they are just highly intelligent people who are using rational evidence to make theories.  i will share with you the most compelling piece of evidence which proves beyond any doubt that the universe is expanding.  and if the universe is expanding... well, it had to start somewhere right? it's just a logical conclusion formulated and agreed upon by very intelligent people, and they didnt just pull it out of their butts.\n\nso here is how we know the universe is expanding: the doppler effect. This is an effect observed with waves, most observably with sound and light waves. Basically, it says that waves moving toward you have a shorter wavelength, and waves moving away from you have a longer wavelength. \n(  (  (  (x)))) -->\nKind of like that, the waves are closer together at the front, kind of like they are being bunched up, they are staying closer to the object(x) since it is moving and getting closer to them. This is the Doppler effect. With sound waves, this effect means that coming toward you, sound waves have a shorter wavelength(notice that the distance between each wave is shorter) and a higher frequency(notice that more waves would pass a given point per second since they're closer together) the formula is v=fw where v is velocity, f is frequency and w is wavelength; as you can see, since v is constant(the speed of light) f and w are inversely proportional so when one goes up, the other goes down. This higher frequency results in a higher pitch of the sound. This has been easily observed with sound.  this means that the waves coming from an object moving away from you has a lower frequency.\n\nWhen dealing with light, these differences in wavelentgh and frequency actually leads to a change in color, because the different colors just correspond to different wavelengths of light.(speeds must be very high to observe these changes) When an object is moving toward us, the wavelength is shorter and the frequency is higher, so we observe a "blue shift" because blue has the highest frequency, and when an object is moving farther away, the frequency is lower and wavelenth is longer, so we observe a "red shift," since red has the highest frequency(lowest wavelength, it looks longer, see the 'diagram' i tried to represent above...) \n\nWell, we currently observe a red shift in other stars using strong telescopes, meaning that everything in any direction is getting farther and farther away from us and therefore, the universe is expanding.\n\ni hope i gave you some insight into some of the observations that are made before such a theory is created.  science has much evidence, which is why it is supported by so many intelligent people. scientists are very skeptical and will not believe anything unless proper evidence is presented to them, and even then will not really believe it, just admit that it may have happened that way. like the big bang theory, we didn't say "this is what happened, deal with it", we say "hey, it seems from the evidence that this is a possibility and makes a lot of sense... but it's still just a theory."
478708
Scientifically speaking: There is nothing that humans can do stop the sun from expanding. It will happen whether we like it or not.\nReligiously speaking: Your God should have wiped us out by then.\nOptimistically speaking: We will by then have space-travel and colonize space and spread our distorted DNA all over this universe.\nPessimistically speaking: We are freakin' dead.\nRealistically speaking: We can't even stop the green-house effect, how do you think we will stop a star from expanding its' fuel and dying?\nPersonally speaking: Scotty, beam me up!
444983
A very specific phenomenon called decoupling (specifically the decoupling of the strong force from the electroweak force) generated what amounted to a phase change in the nature of space-time.  This drove  a rapid superluminal expansion called "inflation" or The Big Bang.  Look up inflation on wikipedia.\n\nYou are correct that the universe was expanding just because it was a hot dense ball, but that is only a small part of the story and does NOT explain the expansion we see today.
148859
There is a very basic problem here. If you do a computation of the energy associated with the virtual particles, you get way, way, WAY more than enough to produce a closed universe. By one estimate, the answer is *at least* 63 orders of magnitude off. This is one of the worst predictions ever made! Clearly something is going on and nobody seems to have a good idea about how to get plausible results from this type of calculation. A *lot* of cancellation has to occur.