Black hole vs the speed of light

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ehcuob

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Does matter entering the event horizon of a Black hole ever exceed the speed of light?
 
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alokmohan

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As per General theory of relativity nothing can move at speed of morethan light.This is universal.Talks of faster than light talks are not correct.
 
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lukman

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not necessary, in a singularity, realitvity doesn't work, there is space or time, how can you meausure speed? <div class="Discussion_UserSignature"> </div>
 
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alokmohan

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Since we have no notion as to what happens inside a black hole,and in fact we know so little of singularity ,we may leave it out for the present.Speakig in terms of spacetime,I am to say it is spacetime itself and in singularity time freezes.You have nothing called time in singualarity.For the purpose of discussion,I say black hole and singularity are one and the same thing.
 
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alokmohan

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Scientists have captured [image] for the first time the entire process of a black hole eating a stellar meal. <br /><br /> <br /><br />An orbiting telescope called Galaxy Evolution Explorer, detected bright ultraviolet flares emitted from a star that had ventured too close to the hungry void of a black hole and began to plunge into it. <br /><br /> <br /><br />"This type of event is very rare, so we are lucky to study the entire process from beginning to end," said Suvi Gezari of the California Institute of Technology. <br /><br /> <br /><br />For thousands of years, this black hole most likely rested quietly deep inside an unnamed galaxy before the opportunity for a filling feast came up. <br /><br /> <br /><br />Today, the space-based telescope continues to periodically watch this ultraviolet light fade as the black hole finishes the remaining bits of its meal. <br /><br /> <br /><br />“This will help us greatly in weighing black holes in the universe, and in understanding how they feed and grow in their host galaxies as the universe evolves," said Christopher Martin also of the California Institute of Technology. <br /><br /> <br /><br />In the early 1990s, three other dormant black holes were suspected of having eaten nearby stars when satellites picked up X-ray flares from their host galaxies. <br /><br /> <br /><br />Only with better technology and a decade later were astronomers able to confirm that the black holes' X-rays had faded dramatically—a sign that stars were swallowed.<br /><br /> <br /><br />Black holes are heaps of concentrated matter whose gravity is so strong that even light cannot escape. Supermassive black holes are believed to reside at the cores of every galaxy, though some are thought to be more active than others. <br /><br /> <br /><br />Active black holes drag surrounding material into them, heating it up and causing it to glow. Dormant black holes, like the one at the center of the Milky Way, hardly make a peep, so they are difficult to study.<br /><br /> <br /><br />It’s rar
 
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oscar1

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Measuring the speed of light can only be done taking time into account. Since between the event horizon and the singularity, time is likely compressed into something extremely slow moving, I don't think that we could ever translate the speed of the incoming matter into a speed that we can comprehend.
 
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newtonian

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ehcuob - good question.<br /><br />Relativity may be relatively inaccurate for the inside of the black hole - or it may be entirely accurate, we do not know. Just like Einstein tweaked Newtonian laws of motion, there may be additional tweaking needed for motion inside a black hole.<br /><br />I will leave that to the experts for now.<br /><br />However, theoretical physicists consider tachyons may exist. They would be faster than light forms of matter, with a lower rather than upper speed limit at the speed of light.<br /><br />One might consider whether in a black hole with the extreme attraction to exceed the speed of light, whether some matter may indeed be converted either directly into tachyons or indirectly after being converted into dark energy or even more familiar forms of energy.<br /><br />We do not know the speed limit of dark energy - it might propagate faster than light such that it could keep up with FTL expansion of space while causing it.<br /><br />Matter can be converted into energy, btw - and vice versa - according to the formula: e=mc^2.
 
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alokmohan

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Tacyons exist?Speed of light is limit.Univese containing tacyons has every thing moving at more than speed of light
 
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newtonian

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Oscar1 - Hi!<br /><br />Consider that you are speaking as an observer in our reference point, or some other reference point outside of the event horizon. <br /><br />To us, from our viewpoint, time has stopped for said matter.<br /><br />However, the matter itself experiences time from its own reference point, not ours.<br /><br />That is part of the theory of relativity.<br /><br />I see no reason why it would not continue to travel towards the center of gravity of the black hole, from its own reference point.<br /><br />However, the trajectories of entering matter will be variable, and the effects on the spin of the black hole will also therefore be variable from black hole to black hole.<br /><br />I suspect that spin will increase to the speed of light in some black holes, and also some entering matter may revolve at light speed around the center of gravity.<br /><br />What happens when further decrease in radius would translate into faster than light revolution of matter, or faster than light spin of the black hole?<br /><br />We don't know, of course.<br /><br />But I suspect things we have not observed - it could be something already theorized like tachyons, or dark energy, or something we haven't even dreamed of!<br /><br />Remember, btw, spin rate increases with the decrease in radius. One cannot reach an infinitely tiny radius without also tending to reach infinitely fast spin rate.<br /><br />I posit that infinitely fast spin rate is not possible, and that therefore black holes do not actually become singularities, but rather having variable tiny radii ranging perhaps above to below Planck length.
 
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newtonian

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alokmohan - Thank you for your posted information above about observational evidence involving black holes.<br /><br />On your question - we do not know. But I am simply suggesting that we keep open minds to what might be so that we dont miss something we might assume cannot exist.<br /><br />We have not observed tachyons. They may or may not exist. Certainly, our universe, if it contains tachyons, does not only contain tachons - that is obvious!<br /><br />Do not assume we shall never know it.<br /><br />One day we may determine by cause and effect, without actually seeing the cause.<br /><br />Just like we 'observe' extra solar planets without actually seeing them directly.<br /><br />And like the evidence of the existence of God, whom we also cannot directly see. (Or at least we cannot survive seeing.<br /><br />There are many things we do not know now that science will discover in the future! <br /><br />Rather than saying we shall never know it, I would say we may know it someday in the future - and proceed to try to find out!<br /><br />Who knows, we may one day be able to observe additional things with dark energy telescopes, especially if dark energy propagates FTL!
 
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oscar1

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"To us, from our viewpoint, time has stopped for said matter."<br /><br />I think that you and I have a different way of looking at the world/universe around us. As I see it, we do observe spheres, or dimensions if you like, that are beyond our physics. This is a result of, I reckon, the specific time-flow that is required for us to exist. Nature does however allow us to be fully aware of certain points of contact. Nature has to render us that allowance, for otherwise we couldn't be sane, and hence not be [thinking]. These 'incomprehensibe-to-us' spheres are probably, among other, the at random behaviour of an isotope before reaching half time, quantum mechanics, and, if they do exist, the environs of Black Holes, as well as these Black Holes (singularities?) themselves. <br /><br />What I mean to say is that I cannot imagine a sphere where time has stopped, so I will not be able to understand whatever answer would be given to the underlying question. <img src="/images/icons/frown.gif" /><br /><br />
 
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alokmohan

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General theory fails inside a black hole.Wheeler shows us the way.A fierry marriage between quantum mechanisc and theory of relativity gives new science quantum gravity.Any way anything travelling in black hole faces tidal wave,infinitely stretched and infinitely squeezed.
 
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abhinavkumar_iitr05

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What I think about the speed of the particle inside the black hole is that it is less than the speed of light in its own frame.What actually happens is that the rate of time flow is slowed down drastically near & inside the event horizon.So in its own frame it never crosses the speed of light.<br /><br /><br />For an observer away from the black hole will also notice the same due to the curved nature of space there.<br /><br /><br />So a person/particle never crosses the limit of speed.<br /><br />This can also b supported by the fact that the mass of the falling particle never becomes infinite (as predicted by Special Theory Of Relativity) otherwise it would had engulf all the matter in the space.
 
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alokmohan

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Tachyons never slow down to speed of light.They donot violate casualty.The article rferred in the post says so.
 
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oscar1

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I suggest we race Tachyons and Gravitons. I am curious to find out which one will win. <img src="/images/icons/wink.gif" />
 
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alokmohan

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Of course tachyo wins.But how to get ,only Sudarsan can say.
 
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alokmohan

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Astronomers Discover New Kind of Black-Hole Explosion <br /><br />PRESS RELEASE<br />Date Released: Wednesday, December 20, 2006<br />Source: Pennsylvania State University<br /><br /><br /> <br /><br /> <br /><br />Scientists have discovered what appears to be a new kind of cosmic explosion -- a "hybrid gamma-ray burst" -- which will be the subject of four articles to be published in the journal Nature on 21 December 2006. The scientists include four astrophysicists at Penn State University as well as others around the globe. The burst was discovered with NASA's Swift satellite on 14 June 2006, and has since been studied with over a dozen telescopes, including the Hubble Space Telescope and large ground-based observatories. <br /><br />"Gamma-ray bursts are the most powerful explosions in the Universe, yet they are random and fleeting, never appearing in the same place twice. The only way to study them in detail is to observe them as quickly as possible with the most powerful telescopes we have," explains Derek Fox, assistant professor of astronomy and astrophysics at Penn State. Fox is an author of one of the Nature papers, which presents ground-based and Hubble Space Telescope observations of the fading afterglow of the hybrid gamma-ray burst in optical light. "This burst -- unlike all other long gamma-ray bursts we have seen at close distance -- was not accompanied by a supernova, for reasons we do not yet fully understand." Fox is the Principal Investigator of one of the Hubble Space Telescope programs that contributed data on the hybrid gamma-ray burst. <br /><br />As with other gamma-ray bursts, this hybrid burst is likely signaling the birth of a new black hole. It is unclear, however, what kind of object or objects exploded or merged to create the black hole or, perhaps, something even more bizarre. The hybrid burst exhibits properties of the two known classes of gamma-ray bursts, characterized as "long" and "short," yet has other features that cannot be explained. <br /><</safety_wrapper>
 
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alokmohan

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Tell me if quantum tunnlig is thory only or practically possible?Tell me what is quantum tuneling is in simple words.
 
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oscar1

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Thanks, I find that very interesting. I am looking around if I can find any more on this.
 
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alokmohan

Guest
Of course singularity is a place to visit.It is 10 to the power minus 43 cm.If you can reach singularity,you cross it and go to another space time may be in this universe or other universe.There quatum tunnelling is feasible?
 
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oscar1

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I love spagetti bolonaise, especially with freshly made tomato puree and basil, but I wouldn't like to become it! <img src="/images/icons/wink.gif" />
 
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kyle_baron

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<font color="yellow"><br />Tell me what is quantum tuneling is in simple words.<br /></font><br />Quantum (particle/wave) tunneling (digs thru a barrier). The barrier can be just about anything: a dimension, energy, or mass.<br /><font color="yellow"><br />Tell me if quantum tunnlig is thory only or practically possible?</font><br /><br />Quantum Tunneling is actually based on Heisenburg's Uncertainty "Principle". This states that there is only a probability that a quantum wave will pass thru the barrier. <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>
 
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