tag:blogger.com,1999:blog-22973357.post8058029410872753758..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: The Black Hole Information Loss ParadoxSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger178125tag:blogger.com,1999:blog-22973357.post-37049074778695655362014-09-09T15:13:54.684-04:002014-09-09T15:13:54.684-04:00Great reading, Bee. Thanks for helping to make th...Great reading, Bee. Thanks for helping to make the topic understandable.<br /><br />If an electron falls into a BH, then the No Hair Theorem tells us that lepton number is not preserved by the BH. But if I am an observer outside the event horizon, then I never see the electron cross the EH. In fact any measurement I perform will tell me that the lepton number is preserved outside of the EH. (Anonymoushttps://www.blogger.com/profile/09151399725219820347noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-27362696579044265452013-08-24T04:32:53.352-04:002013-08-24T04:32:53.352-04:00Personally, I think that it is similar to a comput...Personally, I think that it is similar to a computer hard drive, where the information is just over-written. I base this idea off of the principle of "if a hydrogen atom is bonded to an oxygen atom, how do you tell what it was bonded to before that?". Simply put, the information changes once the energy/matter is released from the black hole.Holy Diverhttps://www.blogger.com/profile/01874075090270229815noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-28569597683332878142012-01-21T09:12:28.404-05:002012-01-21T09:12:28.404-05:00Hi Quarkhopper,
That's an interesting questio...Hi Quarkhopper,<br /><br />That's an interesting question. You do not need mass to encode information, but you do at least need energy. However, you can use massless particles. That the collapsing mass gets rid of all information before it forms a horizon is commonly referred to as "bleaching." The problem with this is however, there is no reason why it should happen, and no Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-88443150026654804882012-01-21T09:07:54.088-05:002012-01-21T09:07:54.088-05:00Hi Sintaxes,
As I already explained here, there i...Hi Sintaxes,<br /><br /><a href="http://backreaction.blogspot.com/2008/06/black-hole-information-loss-paradox.html?showComment=1214485800000#c1586473817976837275" rel="nofollow">As I already explained here</a>, there is absolutely no experimental evidence for black hole evaporation. Please read the previous comments before you add a new one. Yes, all of them. Thanks,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-19100949446805232012-01-21T07:53:19.035-05:002012-01-21T07:53:19.035-05:00Have we been able to witness the disappearance of ...Have we been able to witness the disappearance of a black hole yet, or is the idea that they (will) eventually disappear also part of theory?sintaxeshttps://www.blogger.com/profile/05284177923845703588noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-9011071020639389502012-01-20T14:51:41.494-05:002012-01-20T14:51:41.494-05:00[not entirely sure I should open my mouth, my rese...[not entirely sure I should open my mouth, my resembling some kind of food more than a physicist] This might be the silliest proposition in the thread, and maybe it has been answered, but is it possible that the information gets separated from the mass at an early stage and remains outside the horizon? I'm not sure what problems arise from mass without the information to run it in reverse. I&quarkhopperhttps://www.blogger.com/profile/05605625817392483025noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-19341872222373286802010-04-30T17:22:47.044-04:002010-04-30T17:22:47.044-04:00Hi Bee,
I'd like to offer a way of thinking o...Hi Bee,<br /><br />I'd like to offer a way of thinking of Andrew's idea (using entanglement getting information out):<br /><br />Let's say there is an electron inside th BH, which is called particle A.<br />Then there is virtual particle pair B,C (of electron-positron or positron-electron).<br />B falls into BH, and C gets out.<br /><br />Now any measurement done over all three Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-21589851492773948012010-02-10T03:19:22.876-05:002010-02-10T03:19:22.876-05:00Gilesgoatboy: I'm not sure where you got your ...Gilesgoatboy: I'm not sure where you got your impression from on what is the "leading" solution? In my previous post I was listing mechanisms for information recovery. It's not sufficient for that to claim information isn't lost, but you need to know when and how it comes out. For what I know it's still not entirely clear how information recovery is supposed to happen. <Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-79376216110283845942009-12-04T21:51:57.812-05:002009-12-04T21:51:57.812-05:00BTW: the total lack of radiation through a horizon...BTW: the total lack of radiation through a horizon isn't always a feature of classical theory (although some of the logical and definitional structures that we've built up around general relativity certainly make it look that way). <br /><br />In other contexts, the default behaviour of classical horizons tends to be indirect radiation. Imagine a plane of laser light projected at an acuteErkDemon (Eric Baird)https://www.blogger.com/profile/00430413494529535159noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-31827206407977039062009-03-18T05:56:00.000-04:002009-03-18T05:56:00.000-04:00a blackhole decays to a singular point in time, in...a blackhole decays to a singular point in time, information is kept, until <BR/>the instance before time began, and the universe has colapsed back to a singular itself,<BR/>at which point, it has enough energy to overcome the reduced time colapsed information,<BR/>and retreive it as latent radiation from within the time singular, which becomes<BR/>invisible, along with the information until the Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-15609960738234890672008-12-09T15:33:00.000-05:002008-12-09T15:33:00.000-05:00Hi Gerry,Energy conservation is an assumption. The...Hi Gerry,<BR/><BR/>Energy conservation is an assumption. The calculation is done in a semi-classical approximation, meaning the background is fixed, meaning the energy extracted from it is not taken into account in the calculation but added later as a request of consistency, such that if radiation is emitted the mass of the black hole shrinks by the respective amount. This is also the reason why Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-92100440268716434262008-12-08T15:13:00.000-05:002008-12-08T15:13:00.000-05:00I like the (e-mail) tunneling solution. Most parad...I like the (e-mail) tunneling solution. Most paradoxes (paradi?) are only so due to the frame of reference. Once the big(ger) picture is perceived, the paradox (not the information) disappears.<BR/><BR/>If the singularity is simply the end-point to another location (i.e., a "worm-hole" through space-time), then the information is not lost but re-located. It seems to be lost because we are not Cosmogenium's Convohttps://www.blogger.com/profile/06017166958542831638noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-49589104477172655892008-07-31T05:19:00.000-04:002008-07-31T05:19:00.000-04:00Hi Bee,I had a chance to look back over our discus...Hi Bee,<BR/><BR/>I had a chance to look back over our discussion and read some of the references.<BR/><BR/>You agree with me that the issue is the non-unitarity, not any specific definition of information, but you still talk about the issue of "getting the information out". As long as the evolution is unitary, it doesn't matter whether the information gets out or not, as information is such a Eujinhttps://www.blogger.com/profile/11305131956031966601noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-30266688274996002702008-07-12T12:37:00.000-04:002008-07-12T12:37:00.000-04:00Bee, if you are interested in the idea of Horowitz...Bee, if you are interested in the idea of Horowitz and Maldacena, I found this paper (by checking who cited them....)<BR/><BR/>http://arxiv.org/abs/0806.3818<BR/><BR/>Maybe this helps to answer why you should care about that antidesitter black hole case? Though the author doesnt claim to solve the problem.<BR/><BR/>By the way, there are some nice trackbacks to the HM paper.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-50337267301720961922008-07-11T10:16:00.000-04:002008-07-11T10:16:00.000-04:00OK, maybe one needs to think about this a bit more...OK, maybe one needs to think about this a bit more. But here's a quick example that might be interesting and help give an idea of what I am thinking of.<BR/><BR/>Forget black holes for a moment. Imagine I have a very large number of photons and a hydrogen atom. The photons all have energies that correspond to atomic transitions of the hydrogen electon. I would surely need a lot of bits to Eujinhttps://www.blogger.com/profile/11305131956031966601noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-56943972422147406462008-07-11T09:47:00.001-04:002008-07-11T09:47:00.001-04:00Because, in your version of squashing you have squ...Because, in your version of squashing you have squashed bits into each other and thrown some out. Think of bits as being positions and momenta in the classical version or whatever commuting quantum variables in the quantized version. You sqash them away, you don't any longer know what you had previously. Such a process can't be unitary.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-52457009060047968792008-07-11T09:47:00.000-04:002008-07-11T09:47:00.000-04:00I have to go bed soon. It is late in my timezone. ...I have to go bed soon. It is late in my timezone. Let me know what parts of my arument you agree with and what parts you disagree with and I'll try to check back on Monday (going away for the weekend).<BR/><BR/>I think we agree that the distinction between event horizons and trapping horizons is important to the problem.<BR/><BR/>And we also agree that there are numerous places where Hawking may Eujinhttps://www.blogger.com/profile/11305131956031966601noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-53724979112108595382008-07-11T09:45:00.000-04:002008-07-11T09:45:00.000-04:00How do you want to do that, you'd have to dramatic...How do you want to do that, you'd have to dramatically reduce the basis of the Hilbert space. Consider you create two entangled particle pairs, 1: up-down, 2: down-up, the first of which falls in, the other goes out. Now you need to encode 1: up 2: down, how do you do that with only one state? Besides this, that doesn't explain how the information from inside comes out, see above discussion with Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-46210089865642254892008-07-11T09:43:00.000-04:002008-07-11T09:43:00.000-04:00"If the process isn't one-to-one and 'squashes bit..."If the process isn't one-to-one and 'squashes bits' into each other it can't be unitary, see above, the opposite could be the case though (i.e. even if you don't squash, it doesn't have to be unitary)."<BR/><BR/>I don't understand how you can conclude it won't be unitary if you squash enough, as you don't have a theory that is operable at these densities. I do agree that one needs to answer thisEujinhttps://www.blogger.com/profile/11305131956031966601noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-16103992413440556772008-07-11T09:37:00.000-04:002008-07-11T09:37:00.000-04:00"No, you don't need a large amount of energy. But ..."No, you don't need a large amount of energy. But if you don't have the large amount of energy you need a long time with the above mentioned problems."<BR/><BR/>Why? I don't understand. Even if just one particle comes out right at the end, but it is entangled with all the other Hawking radiation particles that led to the evaporation, won't it still be unitary?Eujinhttps://www.blogger.com/profile/11305131956031966601noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-42161671080817289832008-07-11T09:36:00.000-04:002008-07-11T09:36:00.000-04:00If the process isn't one-to-one and 'squashes bits...If the process isn't one-to-one and 'squashes bits' into each other it can't be unitary, see above, the opposite could be the case though (i.e. even if you don't squash, it doesn't have to be unitary).Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-9846514689239350672008-07-11T09:34:00.000-04:002008-07-11T09:34:00.000-04:00Really one should ask, what happens when a large n...Really one should ask, what happens when a large number of particles are squashed up real close to one another? <BR/><BR/>If this process violates "number of bits" conservation, like baryon number and the like, then so be it. I don't see why it should violate unitarity though.<BR/><BR/>The problem is the violation of unitarity. Nothing else.Eujinhttps://www.blogger.com/profile/11305131956031966601noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-81475346791464922322008-07-11T09:33:00.000-04:002008-07-11T09:33:00.000-04:00No, you don't need a large amount of energy. But i...No, you don't need a large amount of energy. But if you don't have the large amount of energy you need a long time with the above mentioned problems.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-13108877629099931332008-07-11T09:29:00.000-04:002008-07-11T09:29:00.000-04:00"The problem with not having any modification alre..."The problem with not having any modification already at small energy densities is that then you run into the mentioned problem of there being not enough energy left to eventually get the information out with."<BR/><BR/>So the information can somehow be measured in some number of bits? What is the minimal set of bits that I need to describe some gas of particles. Can I do this?<BR/><BR/>Things Eujinhttps://www.blogger.com/profile/11305131956031966601noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-69546414310723807072008-07-11T09:24:00.000-04:002008-07-11T09:24:00.000-04:00Hi Eujin,The interesting thing to look at is what ...Hi Eujin,<BR/><BR/><I>The interesting thing to look at is what happens to the ingoing negative energy states generated by the Hawking radiation when they catch up with the originally collapsed matter, near or at the centre of the black hole. No one ever really answers this question.</I><BR/><BR/>Yes, this is indeed the interesting question. Problem is one can't address it without knowing what Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.com