Re: [math-fun] "firewall paradox" about black holes
From _our_ perspective of the outside world, things that 'fall into' the black hole _never get there_, because time just gets slower & slower (GR time dilation) until at the horizon itself time stops. So all of the _information_ that 'fell into' the black hole still resides in our universe, except that from our perspective it is now painted on the _surface_ of the black hole. This is one way to see Bekenstein's argument that the information 'content' of a black hole is proportional to its surface area. --- BTW, I was watching a lecture at UCSB's KITP where the claim was made that particles that 'fall into' a black hole 'release' an amount of energy equal to their gravitational potential energy, which can be ~ 50% of their _rest mass_. I haven't done the calculations, but if we can attribute the 'rest mass' of a particle to its _potential energy_ as a result of being pulled out of a black hole, who needs Higgs Bosons to give us rest mass ? So we get all of our mass from the potential energy from being separated from every other mass in the universe? Mach was right, after all: http://en.wikipedia.org/wiki/Mach's_principle At 04:38 PM 8/13/2013, Warren D Smith wrote:
in NY Times today, graphic is here:
http://www.nytimes.com/interactive/2013/08/13/science/0813-sci-blackhole.htm...
does my (already discussed) quantum decoherence picture already resolve this paradox? Needs thought...
On 8/13/2013 5:37 PM, Henry Baker wrote:
From _our_ perspective of the outside world, things that 'fall into' the black hole _never get there_, because time just gets slower & slower (GR time dilation) until at the horizon itself time stops.
That's not quite right. The Gravitational redshift makes the photons coming to us later and later so that it takes indefinitely long for us to see the thing falling thru the event horizon. But for the thing proper time (as it reads on its clock) is quite finite.
So all of the _information_ that 'fell into' the black hole still resides in our universe, except that from our perspective it is now painted on the _surface_ of the black hole.
Except there are other perspectives - like that of the guy falling into the black hole and we want our theories of physics to apply equally to all points of view.
This is one way to see Bekenstein's argument that the information 'content' of a black hole is proportional to its surface area.
--- BTW, I was watching a lecture at UCSB's KITP where the claim was made that particles that 'fall into' a black hole 'release' an amount of energy equal to their gravitational potential energy, which can be ~ 50% of their _rest mass_.
I think they meant that's the ideal amount you could get by adiabatically lowering a particle into a BH. There's no mechanism for a particle to just 'release' energy (photons?) as it falls into a BH.
I haven't done the calculations, but if we can attribute the 'rest mass' of a particle to its _potential energy_ as a result of being pulled out of a black hole, who needs Higgs Bosons to give us rest mass ?
So we get all of our mass from the potential energy from being separated from every other mass in the universe? Mach was right, after all:
The Higgs field is needed to give *rest mass* to the weakly interacting particles. Photons for example have gravitational potential energy without having rest mass. Nucleons get most of their mass from the kinetic energy of the bound quarks. Brent
http://en.wikipedia.org/wiki/Mach's_principle
At 04:38 PM 8/13/2013, Warren D Smith wrote:
in NY Times today, graphic is here:
http://www.nytimes.com/interactive/2013/08/13/science/0813-sci-blackhole.htm...
does my (already discussed) quantum decoherence picture already resolve this paradox? Needs thought...
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Really smart guys are confused by this issue. And even Ed Witten is staying silent. To me, that means that the jury is still out while the experts digest things. Rowan. On Tue, Aug 13, 2013 at 6:49 PM, meekerdb <meekerdb@verizon.net> wrote:
On 8/13/2013 5:37 PM, Henry Baker wrote:
From _our_ perspective of the outside world, things that 'fall into' the black hole _never get there_, because time just gets slower & slower (GR time dilation) until at the horizon itself time stops.
That's not quite right. The Gravitational redshift makes the photons coming to us later and later so that it takes indefinitely long for us to see the thing falling thru the event horizon. But for the thing proper time (as it reads on its clock) is quite finite.
So all of the _information_ that 'fell into' the black hole still resides in our universe, except that from our perspective it is now painted on the _surface_ of the black hole.
Except there are other perspectives - like that of the guy falling into the black hole and we want our theories of physics to apply equally to all points of view.
This is one way to see Bekenstein's argument that the information 'content' of a black hole is proportional to its surface area.
--- BTW, I was watching a lecture at UCSB's KITP where the claim was made that particles that 'fall into' a black hole 'release' an amount of energy equal to their gravitational potential energy, which can be ~ 50% of their _rest mass_.
I think they meant that's the ideal amount you could get by adiabatically lowering a particle into a BH. There's no mechanism for a particle to just 'release' energy (photons?) as it falls into a BH.
I haven't done the calculations, but if we can attribute the 'rest mass' of a particle to its _potential energy_ as a result of being pulled out of a black hole, who needs Higgs Bosons to give us rest mass ?
So we get all of our mass from the potential energy from being separated from every other mass in the universe? Mach was right, after all:
The Higgs field is needed to give *rest mass* to the weakly interacting particles. Photons for example have gravitational potential energy without having rest mass. Nucleons get most of their mass from the kinetic energy of the bound quarks.
Brent
http://en.wikipedia.org/wiki/**Mach's_principle<http://en.wikipedia.org/wiki/Mach's_principle>
At 04:38 PM 8/13/2013, Warren D Smith wrote:
in NY Times today, graphic is here:
http://www.nytimes.com/**interactive/2013/08/13/** science/0813-sci-blackhole.**html<http://www.nytimes.com/interactive/2013/08/13/science/0813-sci-blackhole.html>
does my (already discussed) quantum decoherence picture already resolve this paradox? Needs thought...
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Things can fall into a black hole; they penetrate the event horizon and then reach the central singularity in a finite proper time, about a millisecond for a solar mass black hole. Signals emitted after the object enters the event horizon cannot exit. The object emits, in its own rest frame, a finite number of photons per unit time. The external observer detects only finitely many photons, although no upper bound can placed on the arrival time of the last photon. After that, all contact is lost. I'm not sure what meaning can be attached to the statement "So all of the _information_ that 'fell into' the black hole still resides in our universe, except that from our perspective it is now painted on the _surface_ of the black hole." This is not something that can be experimentally verified. The stuff isn't just sitting there on the event horizon. An object falling into a black hole loses energy only if it collides with other objects on its way in, as in an accretion disk. In the absence of such dissipation, the object carries all its energy inside. The total energy, rest + kinetic, of the object at infinity, and then divided by c^2, is the mass increase of the black hole. Subtract from that total energy, any energy radiated away to infinity by dissipation. -- Gene
________________________________ From: Henry Baker <hbaker1@pipeline.com> To: math-fun <math-fun@mailman.xmission.com> Sent: Tuesday, August 13, 2013 5:37 PM Subject: Re: [math-fun] "firewall paradox" about black holes
From _our_ perspective of the outside world, things that 'fall into' the black hole _never get there_, because time just gets slower & slower (GR time dilation) until at the horizon itself time stops.
So all of the _information_ that 'fell into' the black hole still resides in our universe, except that from our perspective it is now painted on the _surface_ of the black hole.
This is one way to see Bekenstein's argument that the information 'content' of a black hole is proportional to its surface area.
--- BTW, I was watching a lecture at UCSB'sKITP where the claim was made that particles that 'fall into' a black hole 'release' an amount of energy equal to their gravitational potential energy, which can be ~ 50% of their _rest mass_.
I haven't done the calculations, but if we can attribute the 'rest mass' of a particle to its _potential energy_ as a result of being pulled out of a black hole, who needs Higgs Bosons to give us rest mass ?
So we get all of our mass from the potential energy from being separated from every other mass in the universe? Mach was right, after all:
http://en.wikipedia.org/wiki/Mach's_principle
At 04:38 PM 8/13/2013, Warren D Smith wrote:
in NY Times today, graphic is here:
http://www.nytimes.com/interactive/2013/08/13/science/0813-sci-blackhole.htm...
does my (already discussed) quantum decoherence picture already resolve this paradox? Needs thought...
I believe this is exactly the contradiction that Hawking and Susskind et. al. have been wrestling with for decades. On Tue, Aug 13, 2013 at 8:09 PM, Eugene Salamin <gene_salamin@yahoo.com>wrote:
Things can fall into a black hole; they penetrate the event horizon and then reach the central singularity in a finite proper time, about a millisecond for a solar mass black hole. Signals emitted after the object enters the event horizon cannot exit. The object emits, in its own rest frame, a finite number of photons per unit time. The external observer detects only finitely many photons, although no upper bound can placed on the arrival time of the last photon. After that, all contact is lost. I'm not sure what meaning can be attached to the statement "So all of the _information_ that 'fell into' the black hole still resides in our universe, except that from our perspective it is now painted on the _surface_ of the black hole." This is not something that can be experimentally verified. The stuff isn't just sitting there on the event horizon.
An object falling into a black hole loses energy only if it collides with other objects on its way in, as in an accretion disk. In the absence of such dissipation, the object carries all its energy inside. The total energy, rest + kinetic, of the object at infinity, and then divided by c^2, is the mass increase of the black hole. Subtract from that total energy, any energy radiated away to infinity by dissipation.
-- Gene
________________________________ From: Henry Baker <hbaker1@pipeline.com> To: math-fun <math-fun@mailman.xmission.com> Sent: Tuesday, August 13, 2013 5:37 PM Subject: Re: [math-fun] "firewall paradox" about black holes
From _our_ perspective of the outside world, things that 'fall into' the black hole _never get there_, because time just gets slower & slower (GR time dilation) until at the horizon itself time stops.
So all of the _information_ that 'fell into' the black hole still resides in our universe, except that from our perspective it is now painted on the _surface_ of the black hole.
This is one way to see Bekenstein's argument that the information 'content' of a black hole is proportional to its surface area.
--- BTW, I was watching a lecture at UCSB'sKITP where the claim was made that particles that 'fall into' a black hole 'release' an amount of energy equal to their gravitational potential energy, which can be ~ 50% of their _rest mass_.
I haven't done the calculations, but if we can attribute the 'rest mass' of a particle to its _potential energy_ as a result of being pulled out of a black hole, who needs Higgs Bosons to give us rest mass ?
So we get all of our mass from the potential energy from being separated from every other mass in the universe? Mach was right, after all:
http://en.wikipedia.org/wiki/Mach's_principle
At 04:38 PM 8/13/2013, Warren D Smith wrote:
in NY Times today, graphic is here:
http://www.nytimes.com/interactive/2013/08/13/science/0813-sci-blackhole.htm...
does my (already discussed) quantum decoherence picture already resolve
this paradox?
Needs thought...
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Hello, but ? , ok let's say that hypothesis 1 is good then suppose someone trows a copy of the week-end edition of the NYT, the big one then waits a while , perhaps a very long time : How the information is restored ??? The journal just pops out in thin air untouched ? Does this makes sense ? Simon Plouffe
Or, ironically, the New York Times website is down at the moment, for reasons that are apparently not yet known. Think of all the information that might be destroyed. --Dan On 2013-08-13, at 11:44 PM, Simon Plouffe wrote:
Hello,
but ? , ok let's say that hypothesis 1 is good then suppose someone trows a copy of the week-end edition of the NYT, the big one then waits a while , perhaps a very long time :
How the information is restored ??? The journal just pops out in thin air untouched ? Does this makes sense ?
Simon Plouffe
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P.S. At least the home page just went back up after being down for about an hour. No mention of the downtime currently appears on the home page. D. On 2013-08-14, at 9:58 AM, Dan Asimov wrote:
Or, ironically, the New York Times website is down at the moment, for reasons that are apparently not yet known. Think of all the information that might be destroyed.
--Dan
On 2013-08-13, at 11:44 PM, Simon Plouffe wrote:
Hello,
but ? , ok let's say that hypothesis 1 is good then suppose someone trows a copy of the week-end edition of the NYT, the big one then waits a while , perhaps a very long time :
How the information is restored ??? The journal just pops out in thin air untouched ? Does this makes sense ?
Simon Plouffe
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firewall problem. On Wed, Aug 14, 2013 at 9:58 AM, Dan Asimov <dasimov@earthlink.net> wrote:
Or, ironically, the New York Times website is down at the moment, for reasons that are apparently not yet known. Think of all the information that might be destroyed.
--Dan
On 2013-08-13, at 11:44 PM, Simon Plouffe wrote:
Hello,
but ? , ok let's say that hypothesis 1 is good then suppose someone trows a copy of the week-end edition of the NYT, the big one then waits a while , perhaps a very long time :
How the information is restored ??? The journal just pops out in thin air untouched ? Does this makes sense ?
Simon Plouffe
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-- Thane Plambeck tplambeck@gmail.com http://counterwave.com/
Clearly, if you throw your NYT into a black hole, it won't magically reappear intact at some future date. But you don't have to be that dramatic, you can simply burn your NYT and grind the ashes to powder, after which it would be similarly unlikely to return to its former state. However, suppose you had a time machine that you could use to reverse time. Now burn you NYT and grind it to ash powder. Ostensibly, because our physics works in either time direction, you could use your machine to reverse time and ungrind and unburn your NYT and thus recover its original form amenable to reading. Thus when the NYT was burned and ground, no information was actually lost, it was just transformed into a state you couldn't read. Likewise, if the universe preserves information, then the identity of Jack the Ripper, the fate of Ambrose Bierce, and Fermat's proof of his last theorem are locked away in the present state of things, and could presumably be recovered by reversing time. If black holes indeed devour information, then if you dropped your NYT into a black hole, even a time-reversal machine could not recover the lost information. Do I have this right?
-----Original Message----- From: math-fun-bounces@mailman.xmission.com [mailto:math-fun- bounces@mailman.xmission.com] On Behalf Of Simon Plouffe Sent: Wednesday, August 14, 2013 2:44 AM To: math-fun@mailman.xmission.com Subject: Re: [math-fun] "firewall paradox" about black holes
Hello,
but ? , ok let's say that hypothesis 1 is good then suppose someone trows a copy of the week-end edition of the NYT, the big one then waits a while , perhaps a very long time :
How the information is restored ??? The journal just pops out in thin air untouched ? Does this makes sense ?
Simon Plouffe
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
You're asking me? But seriously: Don't black holes lead to a singularity of the usual physics equations? I suppose the event horizon occurs before this singularity is reached. But I imagine no one knows what happens when the singularity is reached -- is that the case? If so, are there widely believed hypotheses about what happens? E.g., maybe at that point a black hole behaves like a star in reverse time? Or (woo-woo) gives rise to a disjoint piece of the universe? --Dan On 2013-08-17, at 10:33 AM, David Wilson wrote:
Clearly, if you throw your NYT into a black hole, it won't magically reappear intact at some future date. But you don't have to be that dramatic, you can simply burn your NYT and grind the ashes to powder, after which it would be similarly unlikely to return to its former state.
However, suppose you had a time machine that you could use to reverse time. Now burn you NYT and grind it to ash powder. Ostensibly, because our physics works in either time direction, you could use your machine to reverse time and ungrind and unburn your NYT and thus recover its original form amenable to reading. Thus when the NYT was burned and ground, no information was actually lost, it was just transformed into a state you couldn't read. Likewise, if the universe preserves information, then the identity of Jack the Ripper, the fate of Ambrose Bierce, and Fermat's proof of his last theorem are locked away in the present state of things, and could presumably be recovered by reversing time.
If black holes indeed devour information, then if you dropped your NYT into a black hole, even a time-reversal machine could not recover the lost information.
Do I have this right?
On 8/17/2013 10:58 AM, Dan Asimov wrote:
You're asking me?
But seriously: Don't black holes lead to a singularity of the usual physics equations? I suppose the event horizon occurs before this singularity is reached.
Right. The event horizon contains the singularity. For a large BH, as at the center of the galaxy it is many years from the event horizon to the singularity (and that's the way to put it because once you're inside the event horizon the singularity isn't in a different place from you, it's in your future at the same place, i.e. you don't "move to it" rather "it happens to you".
But I imagine no one knows what happens when the singularity is reached -- is that the case?
Right, although no one really believes there's a singularity, only that general relativity no longer applies. And most physicists hope/believe that when the relation between quantum mechanics and gravity is understood it will explain how the singularity is just an approximation.
If so, are there widely believed hypotheses about what happens? E.g., maybe at that point a black hole behaves like a star in reverse time? Or (woo-woo) gives rise to a disjoint piece of the universe?
Lee Smolin has theorized that the "singularity" gives rise to another universe - but I don't think he's been able to work out anything convincing absent the hoped for quantum theory of gravity. The more pressing question seems to be whether information is conserved (as quantum mechanics implies) when stuff falls into a BH and then the BH evaporates (per Hawking radiation). Whether you chose "yes" or "no" some accepted principle of physics gets violated. Brent
I think that all sane physicists know that when a singularity shows up in your calculations it means that the approximations that you are using are breaking down. This is true in particle physics (where renormalization is required to hide the fact that you actually don't know what is happening at infinite momentum in your internal perturbation loops) as well as in general relativity (where the black hole singularity is also approaching energies where a true quantum gravity theory is required). Good physicists recognize the limitations of the theoretical structures that they are using. On Sat, Aug 17, 2013 at 6:43 PM, meekerdb <meekerdb@verizon.net> wrote:
On 8/17/2013 10:58 AM, Dan Asimov wrote:
You're asking me?
But seriously: Don't black holes lead to a singularity of the usual physics equations? I suppose the event horizon occurs before this singularity is reached.
Right. The event horizon contains the singularity. For a large BH, as at the center of the galaxy it is many years from the event horizon to the singularity (and that's the way to put it because once you're inside the event horizon the singularity isn't in a different place from you, it's in your future at the same place, i.e. you don't "move to it" rather "it happens to you".
But I imagine no one knows what happens when the singularity is reached -- is that the case?
Right, although no one really believes there's a singularity, only that general relativity no longer applies. And most physicists hope/believe that when the relation between quantum mechanics and gravity is understood it will explain how the singularity is just an approximation.
If so, are there widely believed hypotheses about what happens? E.g., maybe at that point a black hole behaves like a star in reverse time? Or (woo-woo) gives rise to a disjoint piece of the universe?
Lee Smolin has theorized that the "singularity" gives rise to another universe - but I don't think he's been able to work out anything convincing absent the hoped for quantum theory of gravity. The more pressing question seems to be whether information is conserved (as quantum mechanics implies) when stuff falls into a BH and then the BH evaporates (per Hawking radiation). Whether you chose "yes" or "no" some accepted principle of physics gets violated.
Brent
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participants (8)
-
Dan Asimov -
David Wilson -
Eugene Salamin -
Henry Baker -
meekerdb -
Rowan Hamilton -
Simon Plouffe -
Thane Plambeck