Has Hawking radiation been observed?

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newtonian

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Hawking proposed black holes would evaporate by means of Hawking radiation.<br /><br />By what means?<br /><br />I have heard two scenarios:<br /><br />1. By the dissapearance and reappearance of virtual particles due to exact location being variable rather than constant and involving probability - similar to the exact position of an electron (cloud) in its orbital being variable based on probability.<br /><br />2. By temperature exchange (thermodynamics) whereby a black hole has a temperature which when warmer than the cold space surrounding it - radiates energy.<br /><br />Has any such radiation been observed?<br /><br />Or is it theoretically possible that tachyon radiation is occurring?<br /><br />I am not limiting this to direct observation of said radiation - obviously we could not actually observe tachyons for example.<br /><br />Rather, if radiation is occurring, then loss of mass/energy is occurring. <br /><br />Is there any evidence of this in our universe - loss of mass/energy in black holes?<br /><br />I would include in this, not only large black holes, but also tiny ones - even perhaps sub-atomic black holes.<br /><br />The latter's existence was postulated on one of today's science channel broadcasts, btw.
 
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No it was never observed.<br /><br />Hawking retracted "his position that Information can't escape a black hole after 30 years holding to its theory." - "edited due correct input from Saiph"<br /><br />Read following post:<br />http://uplink.space.com/showthreaded.php?Cat=&Board=sciastro&Number=587610&page=&view=&sb=&o=<br /><br />This is what it was thought to happen (some still do):<br />http://www.astro.princeton.edu/~strauss/ast203/Lectures/Lecture_19.html<br /><br />"In 1974, Steven Hawking showed that black holes are not totally black.<br />Consider the space right at the edge of the event horizon. A pair of<br />particles is formed out of the vacuum; an electron and a positron.<br />Normally, the two would immediately annihilate, but perhaps one of<br />them will fall into the black hole, and the other would escape. The<br />net effect is for the black hole to give off black-body radiation<br />(albeit very slowly), and thus slowly lose mass. So black holes can<br />evaporate on *very* long timescales. Thus for the supermassive black<br />hole at the center of a big quasar, 3 billion solar masses, it will<br />evaporate on a timescale of 4 x 10^{94} years. No wonder no-one has<br />ever seen Hawking radiation!<br /><br />Another way to think about, due to Bekenstein (grad student here in<br />Princeton, working under John Wheeler in the 1970's): entropy is a<br />measure of the disorder of an object; a basic law of thermodynamics is<br />that the entropy of the universe is always increasing. Bekenstein<br />found it useful to consider the entropy of the black hole as related<br />to the surface area of its event horizon. But entropy is always<br />associated with a finite temperature, so it would give off black-bod
 
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nexium

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One reason we have not observed Hawing's radiation is, we have not found any black holes within 10,000 light years of Earth. Sub atomic black holes may zip past daily within 100 kilometers. Ball lightening is possibly caused by extremely small black holes, but probably not. If micro size black holes do not evaporate, they should be very numerous.<br />Black body radiation is generaly infrared photons or longer wave length's, so I am puzzled why these could escape, if visable photons can not escape.<br />It seems to me that all black holes rotate, otherwise what is the rotational energy of the infalling matter converted to? There are a lot of ideas about black holes which are counter intuitive. Neil
 
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willpittenger

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The people attempting to use colliders to create micro black holes claim they would evaporate within milliseconds or less. Supposedly, that is why they are safe to create. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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Saiph

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steve: The black hole comment is a typical hypothetical and you know it. Yes, we'd be dead. But the gravitational forces of a solar mass black hole, and a solar mass star at 1 au are identical.<br /><br />As for micro-black holes. Even if they didn't evaporate, the collisional cross-section (geometric, electromagnetic, and graviational) is very, very small, the speed very, very high. So the micro-BH would rapidly leave earth's viscinity, being far in excess of escape velocity, and the likelyhood of absorbing even an electron is miniscule. In the event that it does absorb an electron, or a proton...the result is...negligible anyway. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>
 
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The comparison at the end of the post is quite clear, it as to do with fact that the Sun has a Schwarzschild radius of approximately 3 km. If you envision the simplest three-dimensional geometry for a black hole, that is a sphere (known as a Schwarzschild black hole), the black hole's surface is known as the event horizon. Behind this horizon, the inward pull of gravity is overwhelming and no information about the black hole's interior can escape to the outer universe. So 3km and you being on Earth you are outside. But it is obvious that if the sun would turn into a black hole it would be dooms day.<br /><br />As for CERN experiments I think Saiph said it all and I believe this discussion ocurred in another thread.
 
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Saiph

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Hawking didn't retract on the issue of matter escaping the black hole. He retracted his position that <i>Information</i> can't escape a black hole. There is a difference. See my last post on your first linked thread for further information on the matter. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>
 
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newtonian

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saiph - OK, I missed your "further information" somehow.<br /><br />Now, Hawking says information can escape a black hole?<br /><br />Not according to Sunday's Science channel broadcast! Of course, that was pre-recorded.<br /><br />So how is information supposed to escape a black hole - not by Hawking radiation - correct?<br /><br />And what definition of information is being used here?<br /><br />I assume the answer to my opening question is: No.<br /><br />But why not????<br /><br />Do any observational experiments confirm this is likely?<br /><br />Or is this all theoretical?
 
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newtonian

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Neil (nexium) - Hi!<br /><br />OK, no black holes within 10,000 ly found? I assume, then, that we cannot measure Hawking radiation from such distances because it would be too tiny to measure?<br /><br />On black holes rotating - yes, I suspect extremely rapidly. I wonder if one approaches zero radius, wouldn't rotation speed exceed the speed of light?<br /><br />Do any rotate at the event horizon?<br /><br />Doesn't rotation cause those jets?
 
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newtonian

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stevehw33 - How would you contain or destroy a dangerous micro-black-hole?<br /><br />Perhaps by causing all matter within danger to revolve around it faster than escape velocity?<br /><br />Why would anyone want to create a black hole?
 
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willpittenger

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<blockquote><font class="small">In reply to:</font><hr /><p>solid evidence that it's safe<p><hr /></p></p></blockquote><br />The only way to do prove it is to do what you are saying we should avoid doing. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>
 
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search

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Good point<br />Post has been corrected<br />Here is your comment on other mentioned thread:<br /><br />"hawkings has said matter can leave a BH, via hawking radiation. however, the position used to be, that radiation held no information about the internal goings on of the BH. Nobody knew how the virtual particles could communicate that. Now he says it does, i.e. he's figured out how the particles can communicate and get information out. So, hakwings admits to being wrong, Information can escape black holes, should really be the title."<br /> <br />Thanks
 
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vogon13

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Hawking radiation has a temperature spectrum whose wavelength is proportional to the mass of the blackhole.<br /><br />Currently, most blackholes in our region of the universe are quite massive, and their resulting Hawking radiation will have an effective temperature far lower than the 2.73 degree cosmic background radiation, and will be exceedingly difficult to detect.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>
 
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kyle_baron

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<i><br />So how is information supposed to escape a black hole... <br />And what definition of information is being used here?</i><br /><br />Information=Wave Function, from The Elegant Universe p.342: "When anything falls into a blackhole, it's wave gets sucked in as well. TO PREDICT THE FUTURE, we need to know all waves today. But if some have escaped down the abyss of blackholes, the information they contain is lost."<br /><br />"Once Hawking informed the world that blackholes radiate, it's mass slowly decreases, and it slowly evaporates. And, as the distance from the center to the event horizon shrinks, regions of space that were previously cut off, re-enter the cosmos. The question is, does the information (waves) re-enter as well?"<br /><br />I personally, don't have a clue. Hawking first said no, now he says yes (and he lost his bet).<br />I paraphrased these statements to make it easier to understand; waves=wave function=particle-wave duality. <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>
 
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newtonian

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kyle_baron - Interesting response. I am still trying to understand what kind of information is involved here.<br /><br />OK, the particle-wave duality nature of the matter that has been sucked in?<br /><br />Meaning it's specific wavelength - its specific properties.<br /><br />Sounds like we are talking about something relevant to how our universe was fine tuned for life at its creation.<br /><br />That involves some very specific properties, and laws, that are manifest in matter/energy in particle/wave properties!<br /><br />To me, the fact that the matter in a black hole is still exerting the same ratio of gravity to mass it had before becoming part of the black hole argues that this type of information has not been lost - otherwise the precise fine tuning of the strength of gravity would vary from its very precise value or strength.<br /><br />On that predicting the future bit - the future is not predestined, in my opinion, such that it could be seen by anyone in any circumstance by any method.<br /><br />Of course, there are patterns caused by informational properties along with chance or statistical properties based on pre-set factors - notably the laws and properties of our universe and its parts including matter in black holes.
 
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newtonian

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stevehw33 - good posts.<br /><br />Well, Einstein refined Newtonian laws, so why not QM refining Einstein?<br /><br />Did Einstein rule out FTL tachyons, for example?<br /><br />Yes, I did hear about reported FTL experiments - interesting indeed!<br /><br />To me the statistical location of atomic particles (waves), notably electrons, is somewhat different than actual speed - though I do agree that the changed location could be beyond what could be travelled at light speed.<br /><br />But might this be more akin to the FTL expansion of space rather than actual speed of matter on the fabric of space?<br /><br />Sounds like pursuing this subject will naturally lead us to the question of dark energy.<br /><br />E.g.: can dark energy escape a black hole?
 
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kyle_baron

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<i><br />kyle_baron - Interesting response. I am still trying to understand what kind of information is involved here. <br /><br />OK, the particle-wave duality nature of the matter that has been sucked in? <br /><br />Meaning it's specific wavelength - its specific properties.</i><br /><br />Exactly, that's how I understood it.<br /><i><br /> On that predicting the future bit - the future is not predestined, in my opinion, such that it could be seen by anyone in any circumstance by any method. </i><br /><br />I agree with you 100%. But that's not stopping some physicists. One in particular- David Deutsch in Oxford England. From Discover Mag. 2001: .....a team at Oxford with whom Deutsch works are trying to build a quantum computer that would manipulate atoms or photons and exploit the particles ability to exist simultaneously in more than one state. It could in theory perform more steps than there are atoms in the entire universe. To do that, it would have to draw on resources in other universes for storing all that information, and manipulating it. <br /><br />He wants to know everything about everything. I think that he wants to be like God. I personally prefer to be somewhat ignorant. <img src="/images/icons/wink.gif" /><br /><br /> <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>
 
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newtonian

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kyle_baron - Off theme, but a natural tangent involving information - quantum computers.<br /><br />Relevant tangents include:<br /><br />"Einstein won the 1921 Nobel Prize for Physics for his way of explaining light. His paper helped lead the way to a new field of science called quantum theory. In turn, quantum theory laid the foundation for a host of applications including nuclear science, electronics, and nanotechnology." - "Awake!," 9/8/05, p. 20.<br /><br />In fact, quantum effects are involved with Hawking radiation, and also quantum computer designs.<br /><br />Another application of quantum effects, coupled with superconductors:<br /><br />"NMRs (nuclear magnetic resonance scanners) and SQUIDs (superconducting quantum interference devices) are machines that can peer into the human body and detect brain waves." -"Awake!," 3/22/88, p. 21.<br /><br />Brain waves plus quantum computers may well help us figure it all out!<br /><br />We will always be somewhat ignorant, but we also will always learn - and God actually invites us to do this:<br /><br />(Romans 1:20) 20 For his invisible [qualities] are clearly seen from the world’s creation onward, because they are perceived by the things made, even his eternal power and Godship. . .<br /><br />The various fields of science involve perceiving from the things made - and belief in God actually adds incentive to learn the various fields of science.<br /><br />Its not that scientists want to be God - rather it is that we were created in God's image including the capability of having wisdom based on accurate knowledge.<br /><br />Of course, there are all kinds of scientists!
 
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newtonian

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kyle_baron - Scientific American had an article on quantum computers in October, 1995.<br /><br />I hope to study it before responding properly.<br /><br />Meanwhile, it has great potential and is only natural that 11 years later some would try to design and construct such a computer.
 
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