tag:blogger.com,1999:blog-22973357.post6436412105688410148..comments2020-12-02T02:53:31.102-05:00Comments on Sabine Hossenfelder: Backreaction: The Black Hole information loss problem is unsolved. Because it’s unsolvable. Sabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger105125tag:blogger.com,1999:blog-22973357.post-91652513291915436702020-11-29T12:42:07.346-05:002020-11-29T12:42:07.346-05:00Is there a symmetry associated with the conservati...Is there a symmetry associated with the conservation of information?Wyrd Smythehttps://www.blogger.com/profile/06694506351266400927noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-78628244073557378992020-11-28T16:05:26.267-05:002020-11-28T16:05:26.267-05:00manyoso: I think the point of Sabine's book is...manyoso: I think the point of Sabine's book is that jusst using math blindly without intuition won't get you anywhere. But on the flip side, intuition without math is also certainly not going to get you anywhere.<br /><br />Peter Shorhttps://www.blogger.com/profile/13823970640202949073noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-58786755368771440322020-11-27T02:31:05.790-05:002020-11-27T02:31:05.790-05:00The stone can in principle reach the rocket, SR pr...<i>The stone can in principle reach the rocket, SR predicts...</i><br /><br />Again, a rocket with constant (and eternal) proper acceleration can be reached from some events but not from others. The hyperbolic worldline of the rocket is asymptotic to two light lightlines, and the events in the “wedge” region behind the “fulcrum” event (origin of the asymptotic lightlines) are not in the causal Amoshttps://www.blogger.com/profile/00595591283398023248noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-4793738767017001052020-11-26T16:04:19.553-05:002020-11-26T16:04:19.553-05:00Amos, the stone can in principle reach the rocket,...Amos, the stone can in principle reach the rocket, SR predicts, and that's enough to show a violation of the EP. GR predicts the stone can't reach the rocket, not even in principle. The difference between "can in principle" and "can't, not even in principle" is unambiguously contradictory. SR's and GR's predictions can differ in a LIF, I showed.<br /><br />Tom Fuchshttps://www.blogger.com/profile/17646011875919892992noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-54942329470539727122020-11-26T11:12:35.039-05:002020-11-26T11:12:35.039-05:00I can use SR's equations to make predictions a...<i>I can use SR's equations to make predictions as to, say, how long that'd take in the rocket's or the stone's frame. GR predicts that the stone can't reach the rocket.</i><br /><br />Not true. In flat spacetime (where special relativity applies), special and general relativity make identical predictions. <br /><br /><i>SR predicts that the stone can reach the rocket in Amoshttps://www.blogger.com/profile/00595591283398023248noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-83725564285476551492020-11-25T19:54:40.659-05:002020-11-25T19:54:40.659-05:00Amos, SR predicts that the stone can reach the roc...Amos, SR predicts that the stone can reach the rocket in principle; I can use SR's equations to make predictions as to, say, how long that'd take in the rocket's or the stone's frame. GR predicts that the stone can't reach the rocket. That contradiction violates the EP, which says that SR's laws must hold in any and every local inertial frame (LIF). To make your case that Tom Fuchshttps://www.blogger.com/profile/17646011875919892992noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-29157536047199107692020-11-25T12:53:39.053-05:002020-11-25T12:53:39.053-05:00Your answer here is that physicists just need to d...Your answer here is that physicists just need to do *more* math and eliminate all the current assumptions they rely upon by replacing them with more math. And that's precisely why Sabine wrote a book called "Lost in Math." Frankly, if you have read that book and watched this video and you *still* insist that the problem with these "solutions" is that they just don't manyosohttps://www.blogger.com/profile/12384195364005229109noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-2012756097567626622020-11-25T10:06:13.591-05:002020-11-25T10:06:13.591-05:00In [terms of] the [inertial] entity's frame [a...<i>In [terms of] the [inertial] entity's frame [an accelerating] rocket can be any distance away…</i><br /><br />Right. There are no “horizons” in terms of inertial coordinate systems.<br /><br /><i>[General relativity] does violate the [equivalence principle], because according to [special relativity] a freely falling stone below the event horizon can in principle reach a rocket that hoversAmoshttps://www.blogger.com/profile/00595591283398023248noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-72388566658766449232020-11-25T07:35:45.520-05:002020-11-25T07:35:45.520-05:00The emission of photons by a thermal body is treat...The emission of photons by a thermal body is treated by Fermi's golden rule. You can look that up. This describes the spontaneous emission of photons by a system with lots of excited states or energy such as a hot body. This system is considered with a density of states with small transitions relative to the total energy.<br /><br />Hawking radiation is related to to this. This converges to aLawrence Crowellhttps://www.blogger.com/profile/12090839464038445335noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-1210108451213140722020-11-25T01:44:18.577-05:002020-11-25T01:44:18.577-05:00Photons are quanta. They're not classical. I d...Photons are quanta. They're not classical. I don't know how you want to classically emit a quantum, that doesn't make any sense.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-39591037211777229642020-11-25T01:27:14.893-05:002020-11-25T01:27:14.893-05:00If a classical black body emits single thermal pho...If a classical black body emits single thermal photon, does the photon carry information away from the black body?<br /><br />I guess in other words the question is equal to: If a classical black body emits a single thermal photon, is the process time reversible?<br /><br />-TopiTopi Rinkinenhttps://www.blogger.com/profile/10274807062102966219noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-80020840911357487452020-11-25T00:08:00.823-05:002020-11-25T00:08:00.823-05:00The spectrum is the same, yes.The spectrum is the same, yes.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-80346887984755008462020-11-24T15:59:49.351-05:002020-11-24T15:59:49.351-05:00Bee,
I guess BH thermal radiation is equal to bla...Bee,<br /><br />I guess BH thermal radiation is equal to black body thermal radiation, right?<br /><br />How is the reversibility preserved in black body thermal radiation?<br /><br />-TopiTopi Rinkinenhttps://www.blogger.com/profile/10274807062102966219noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-24174361065116364772020-11-24T15:14:51.868-05:002020-11-24T15:14:51.868-05:00Amos, when in the chasing entity's frame the r...Amos, when in the chasing entity's frame the rocket can be any distance away in principle, GR does violate the EP, because then according to SR a freely falling stone below the event horizon can in principle reach a rocket that hovers above the event horizon. The rocket is some distance away from the stone in the stone's LIF, which meets the requirement of "any distance away". Tom Fuchshttps://www.blogger.com/profile/17646011875919892992noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-16225928155470689272020-11-24T11:09:48.365-05:002020-11-24T11:09:48.365-05:00I already agreed that "the chasing entity alw...<i>I already agreed that "the chasing entity always crosses the x axis at a distance less than c^2/a from where the hyperbola crosses that axis". </i><br /><br />Yes, that’s the relevant fact, i.e., that’s what people are referring to when they talk about that “horizon” for an accelerating object.<br /><br /><i>In the chasing entity's frame the rocket can be any distance away in Amoshttps://www.blogger.com/profile/00595591283398023248noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-29542811967305913092020-11-24T11:07:22.553-05:002020-11-24T11:07:22.553-05:00Black holes do not propagate information from thei...Black holes do not propagate information from their interior to the exterior in a causal manner. When black hole collide the gravitational radiation produced is from spacetime in the exterior. Thus, when a quantum particle tunnels from the black hole interior to the exterior by Hawking’s original formalism it carries no information about the black hole interior state. <br /><br />We can think of Lawrence Crowellhttps://www.blogger.com/profile/12090839464038445335noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-53792744943904425302020-11-24T10:43:02.170-05:002020-11-24T10:43:02.170-05:00That's the result of Hawking's calculation...That's the result of Hawking's calculation. The assumptions, as I said, are quantum field theory and the approximate validity of general relativity in the small curvature range. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-55124241634251908172020-11-24T10:18:03.618-05:002020-11-24T10:18:03.618-05:00Hi Bee,
One point that often bugs me when reading...Hi Bee,<br /><br />One point that often bugs me when reading about time reversibility paradox, is the statement that black hole evaporation is thermal.<br /><br />I'm sure it is known that it is thermal, but it's not clear for layman reader like me.<br /><br />Would you mind writing a few lines of this? What assumptions are taken to get to the conclusion that the radiation is indeed Topi Rinkinenhttps://www.blogger.com/profile/10274807062102966219noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-83675795159473382232020-11-24T08:39:35.139-05:002020-11-24T08:39:35.139-05:00So many vacuums. So many vacuums. Greg Feildhttps://www.blogger.com/profile/11893021846714172269noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-59806533869830727732020-11-24T08:37:58.216-05:002020-11-24T08:37:58.216-05:00(Most) physicists don't understand probability...(Most) physicists don't understand probability or statistics, nor do they let that slow them down!Greg Feildhttps://www.blogger.com/profile/11893021846714172269noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-33104846196417805432020-11-23T15:00:20.140-05:002020-11-23T15:00:20.140-05:00Amos, I already agreed that "the chasing enti...Amos, I already agreed that "the chasing entity always crosses the x axis at a distance less than c^2/a from where the hyperbola crosses that axis". I said that distance applies only in a LIF that momentarily co-moves with the rocket. The examples I gave from The Relativistic Rocket site prove my point that in the destination's (chasing entity's) frame the rocket can be any Tom Fuchshttps://www.blogger.com/profile/17646011875919892992noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-89488400178737855732020-11-23T10:40:09.174-05:002020-11-23T10:40:09.174-05:00If you were right then a rocket wouldn't be ab...<i>If you were right then a rocket wouldn't be able to accelerate and decelerate to reach any destination.</i><br /><br />Not true. Ordinary motions along ordinary worldlines in flat spacetime, including accelerations and decelerations, are entirely consistent with special relativity, and motion with constant proper acceleration does not present any difficulties or inconsistencies. Again, Amoshttps://www.blogger.com/profile/00595591283398023248noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-89644758974791960402020-11-23T04:34:34.438-05:002020-11-23T04:34:34.438-05:00Amos, if you were right then a rocket wouldn't...Amos, if you were right then a rocket wouldn't be able to accelerate and decelerate to reach any destination; the predictions listed at The Relativistic Rocket site at "Here are some of the times you will age when journeying to a few well known space marks, arriving at low speed" would be wrong. For any distance between a rocket and its destination as measured in the destination'Tom Fuchshttps://www.blogger.com/profile/17646011875919892992noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8032676788549982952020-11-22T14:11:30.929-05:002020-11-22T14:11:30.929-05:00Hyperbolic motion is self-similar in terms of ever...Hyperbolic motion is self-similar in terms of every system of inertial coordinates, and in each of them the spatial distance between the stationary point on the hyperbola and the "fulcrum" event is c^2/a. No, that distance cannot be "any distance" when measured in the stone's frame. You're still confusing different initial conditions. Remember, in some frames the Amoshttps://www.blogger.com/profile/00595591283398023248noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-65640465340998300942020-11-22T12:41:02.589-05:002020-11-22T12:41:02.589-05:00Sabine: You have explained in detail the informati...Sabine: You have explained in detail the informational problems of a black hole.<br /><br />On the other hand, it could be interesting to check the problem in the view of Lorentzian relativity.<br /><br />An essential point is the behavior of the speed of light c in a gravitational field. For Einstein, its variation is a seeming effect because in the view of a curved space-time c does not change.antooneohttps://www.blogger.com/profile/12559038212417783694noreply@blogger.com