I am the first in the world

[Farsight]

No. Hawking is wrong, and Susskind is wrong. It's like picking sides between catholics and protestants. And besides, this thing has been going since 1981. That's thirty years of drummed-up publicity about a so-called "war". Bah.

 

[Dr. Trintignant]

I found the book interesting.

Hawking lost his bet on black hole information, so in that sense he lost. But like all good scientists, once the correct answer was known, he pursued that path with all vigor, and produced papers which describe ways in which black holes can lose information. The exact mechanism is not known for certain yet, though.

- Dr. Trintignant

 

[DC]

thanks for the video, very interesting i love their "war"

 

[Dinwar]

Bah. You physicists are cowards. When we had the Dino Wars, we used explosives. When paleontologists go to war, we GO TO WAR.

Of course, this is also why we're widely considered the red-necks of the science community...

 

[alfa1]

Why they are wrong? Some arguments...

 

[Corsair 115]

For what it's worth, Susskind gave a lecture at the Perimeter Institute in which he talked about the "Black Hole Wars". Quite informative for a layperson such as myself who has a bit of interest in the area. The hour-long lecture was recorded and shown on the TVO program Big Ideas.

TVO does have archives of its past programs, but the lecture was from a few years back so I don't know if they'd still have that episode available.

 

[Brown]

I listened to the book on audio (which can be a challenge especially when mathematics and equations are discussed) and I've written about the book a few times on the forum already:

Let me put in another plug for Leonard Susskind's The Black Hole War. One interesting part of the book is the notion that some physics models have been changing, and changing dramatically, within the past thirty years or so. Another interesting part of the book pertains to the various motivations about why the models have been changing. Some of it is a matter of personal ego, some of it is dogma, some of it is improved mathematical consistency, and some of it (a surprisingly small amount) is due to actual experimental observation.

One theme of the book is that you need to think about existence in new ways. Some of these new ways are counterintuitive, others are seemingly double-think contradictory, and some border upon the insane. Conventionally, we think of something smaller as being lighter (or less massive), yet in a sense, smaller is heavier. Similarly, we think of the smallest things in the universe as being, well, small, when they can actually be as large as the entire universe itself. And we can think of unseen six dimensions as genuine, while also thinking of our own three spatial dimensions--which we CAN see--as really being only two, with the third being an illusion.

This may sound like a positive assessment, and it is, but I find many, many flaws with this work. The flaws are not necessarily scientific, and the fact that what Susskind says is questionable does not add to any validity in position taken by Hawking.

Basically, the Black Hole War was about this: Is information lost in a black hole or not? Hawking thought it was. Susskind thought it was not. Game on, boys.

Now, where are the flaws in Susskind's work? The following come to mind immediately (and given more time to think, I could probably identify others):

• The big one: Susskind repeatedly reports things that are flat out contradictory. Sometimes he points out the contradiction himself, and perhaps even tries to deal with it; and sometimes he does not mention it and acts as if there is no contradiction at all. In listening to this work, I found myself repeatedly saying out loud, "Hey wait a minute, that's inconsistent with what you said a few chapters ago!" One example of inconsistency was whether it is possible for an outsider to observe something falling into a black hole or not. Another example is Susskind's handling of the time frames in which events occur. There were dozens more.
• Important concepts were footnoted, meaning that some of the important concepts were never really discussed in any meaningful detail. Susskind merely referred the reader to the work of another author, and went on his merry way.
• Illustrative imagery was inaccurate, but the inaccuracies were left vague. For example, the notion that mass distorts space is similar to the way a ball distorts a rubber sheet on which it is placed. Susskind is quick to say that this imagery is helpful but not completely accurate. Well, what's right about it, and what's not right? Similar imagery is tossed out again and again, and we're told it isn't quite right, but we aren't told what's inaccurate or what false conclusions we must avoid drawing. I can understand that we need to see things in new ways, but admittedly inaccurate metaphors can sometimes do more to confuse than to clarify.
• Some key distinctions were made that seemed nonsensical, and the distinctions were not discussed to show why they were distinctions at all. For example, there is a pretty damn important difference between having information "scrambled beyond all hope of recognition and recovery," and having the information "destroyed" or "lost." (Evidently the distinction is that the former is reversible in theory, while the latter is not.)
• Key concepts such as "information" are explained poorly. In some cases, I wish another word had word or term had been chosen.
• The last flaw that I shall mention is that the reader is left confused by the difference between models and reality. One example: A three-dimensional existence can be mathematically modeled as a two-dimensional existence. This sort of thing happens all the time: a complex number can be equivalently expressed in two-term rectangular form or single-term polar form; a general cubic equation with four terms can be expressed as a depressed cubic equation with three terms; and so on. But this sort of mathematical equivalence or mapping doesn't necessarily mean that the more economical model is somehow a more correct representation of reality, does it? The fact that the existence of every object in the universe CAN BE expressed mathematically equivalent to a hologram doesn't necessarily mean that the universe IS a hologram, does it??

I strongly suspect that some of the flaws arise from the fact that I listened to the book on audio, and therefore did not have the full benefit of pictures and equations. But I also suspect that Susskind fell into the very same trap that Hawking fell into, namely, that some publisher convinced him: "Now, you don't want to make the book too mathematical, with too many equations. That will just confuse people and will hurt sales."

 

[sol invictus]

The big one: Susskind repeatedly reports things that are flat out contradictory. Sometimes he points out the contradiction himself, and perhaps even tries to deal with it; and sometimes he does not mention it and acts as if there is no contradiction at all. In listening to this work, I found myself repeatedly saying out loud, "Hey wait a minute, that's inconsistent with what you said a few chapters ago!" One example of inconsistency was whether it is possible for an outsider to observe something falling into a black hole or not. Another example is Susskind's handling of the time frames in which events occur. There were dozens more.

Out of curiosity, could you be more specific about those (or others of the dozens)? I'm wondering how many of them are true contradictions, and how many were just counterintuitive or perhaps not well explained.

It's impossible to see or detect something once it's inside the event horizon and you're not, because no light or other signal can get back out. But - at least if information isn't destroyed - in principle you can reconstruct exactly everything that fell in from the radiation emitted by the black hole.

 

[Brown]

Out of curiosity, could you be more specific about those (or others of the dozens)? I'm wondering how many of them are true contradictions, and how many were just counterintuitive or perhaps not well explained.

It's impossible to see or detect something once it's inside the event horizon and you're not, because no light or other signal can get back out. But - at least if information isn't destroyed - in principle you can reconstruct exactly everything that fell in from the radiation emitted by the black hole.

Let me give a few examples, as I do not have the audio book handy (and it would take several hours to go through it again).

Susskind said that as objects approach black holes, from the point of an outside observer, the object never actually reaches the black hole. Later, he described a thought experiment in which outside observers were observing things falling into a black hole. Hey, wait a minute, I thought; didn't you say earlier that this couldn't happen?

Susskind discussed string theory and mentioned that string theory is often criticized because it cannot be tested. He later described several consequences predicted by string theory that would seem to be testable by experiment. Hey, wait a minute; is string theory a model that can make testable predictions about reality or not?

Susskind said a "Xerox" effect is impossible, then later described his view that seemed to be pretty much what the "Xerox" business was. Hey, wait a minute, is that information radiated by the black hole copied or isn't it?

Susskind talked about certain events occurring within particular time intervals. For example, he talked about the time interval between an object entering a black hole and the object being annihilated. Hey, wait a minute, didn't we agree that time is relative and that is seems to slow down from the point of view of an external observer?

These are just the ones I can remember off the top of my head. There were a hell of a lot of "Hey, wait a minute" moments when I listened to the audio book.

Now, I'm not saying Susskind is wrong or that he is truly being contradictory (although he may well be ... his own model of "black hole complementarity"--in which colloquially speaking an object is BOTH totally preserved and utterly demolished by the same event--seems to be a flat contradiction of itself, and Susskind admits as much). But what I am saying is that what SEEMS to be unexplained inconsistency and contradiction is not what we expect from a teacher of science. We expect inconsistency and contradiction from politicians, lawyers, advertisers and salesmen. Not from scientists.

 

[Dr. Trintignant]

It's been a over year since I read the book so I've forgotten a bit, but I'll try to answer some of these.

Susskind said that as objects approach black holes, from the point of an outside observer, the object never actually reaches the black hole. Later, he described a thought experiment in which outside observers were observing things falling into a black hole. Hey, wait a minute, I thought; didn't you say earlier that this couldn't happen?

I don't recall him saying that an outside observer would ever witness something crossing the event horizon. Saying that something is falling into a black hole is just an imprecise way of saying that the something is falling towards it--not necessarily that it has crossed the event horizon. An accretion disk is matter falling into a black hole, for instance.

Susskind discussed string theory and mentioned that string theory is often criticized because it cannot be tested. He later described several consequences predicted by string theory that would seem to be testable by experiment. Hey, wait a minute; is string theory a model that can make testable predictions about reality or not?

Are you sure you aren't overestimating our ability to perform an experiment? It's one thing to say that an experiment isn't physically impossible, and quite another to say that we could actually perform the experiment with practical devices.

Susskind talked about certain events occurring within particular time intervals. For example, he talked about the time interval between an object entering a black hole and the object being annihilated. Hey, wait a minute, didn't we agree that time is relative and that is seems to slow down from the point of view of an external observer?

Again, the outside observer never sees an object cross the event horizon, and I don't recall Susskind ever saying otherwise. So if there is a passage that refers to the time between crossing the horizon and being annihilated, it must refer to the frame of the falling object.

(although he may well be ... his own model of "black hole complementarity"--in which colloquially speaking an object is BOTH totally preserved and utterly demolished by the same event--seems to be a flat contradiction of itself, and Susskind admits as much).

Yes, it sure seems that way. But we have to define carefully what it means to have a contradiction, and it's not clear that an object can be both destroyed and not destroyed as long as the information is preserved. The entire history of physics is littered with commonsense beliefs that we had to give up to make sense of things. It seems like a contradiction that A can observe that X occurs before Y while B observes X after Y, but it's really not once you understand the physics.

- Dr. Trintignant

 

[sol invictus]

Thanks very much for these examples.

I'm not sure if you're interested in clarifications, but in case you are I'll add to what Dr. Trintignant already said.

Susskind said that as objects approach black holes, from the point of an outside observer, the object never actually reaches the black hole. Later, he described a thought experiment in which outside observers were observing things falling into a black hole. Hey, wait a minute, I thought; didn't you say earlier that this couldn't happen?

You can certainly observe things falling towards the horizon. You'd never see them actually cross - which is probably what Susskind meant - but they get extremely close. In fact that's how real black holes are actually observed by astronomers - from the radiation emitted by things falling into them.

Susskind discussed string theory and mentioned that string theory is often criticized because it cannot be tested. He later described several consequences predicted by string theory that would seem to be testable by experiment. Hey, wait a minute; is string theory a model that can make testable predictions about reality or not?

It certainly makes testable predictions, both with current and future tech. The problem is that the predictions that are testable with current tech aren't really unique to string theory - so you could show that string theory is wrong, but it would be hard to convincingly verify it as correct.

Susskind said a "Xerox" effect is impossible, then later described his view that seemed to be pretty much what the "Xerox" business was. Hey, wait a minute, is that information radiated by the black hole copied or isn't it?

The idea is that so long as you only ever (even in principle) have access to one copy, there's no problem. So long as you stay out of the horizon, there's no experiment you can do on the putative copy that fell in. If you jump in, the story is more interesting, but it seems to be consistent.

Susskind talked about certain events occurring within particular time intervals. For example, he talked about the time interval between an object entering a black hole and the object being annihilated. Hey, wait a minute, didn't we agree that time is relative and that is seems to slow down from the point of view of an external observer?

For an external observer, yes. But for the person falling in, those time intervals are finite.

But what I am saying is that what SEEMS to be unexplained inconsistency and contradiction is not what we expect from a teacher of science. We expect inconsistency and contradiction from politicians, lawyers, advertisers and salesmen. Not from scientists.

It seems that in writing such books one needs to be very careful to detect and head off that kind of "hey, wait a minute!" confusions...

 

[Brown]

The elaborations that have been mentioned may be fair (and it might have helped if Susskind had asked us to read his book before he published it, so that he could deal with some of the uncertainties), but the original criticism remains. Susskind gave the impression of contradicting himself (even if, in the end, he didn't really). But it is also true that the concepts he was trying to describe are difficult ones. Damn difficult.

The business about something entering a black hole is an extremely troublesome concept. What does it mean to enter a black hole? What is the border of a black hole? As Susskind explained, the border of the black hole is the event horizon; anything that passes the event horizon cannot escape the black hole. But it turns out that that it also matters who is doing the observing. A person drifting toward an event horizon might not have any sense of anything being amiss and may cross over the event horizon without even realizing it. There's no physical boundary or any tip-off of any change to be detected. (Hey, wait a minute, in the thought experiment where observers dropped a thermometer close to a black hole's event horizon, didn't the thermometer detect a significant change in temperature?) Eventually the person drifting along is going to be annhiliated, but if that person is inside the event horizon, there is no escape! If you crossed the event horizon, whether you realized it or not, you are toast.

What a distant observer sees is quite different, however. They see the person drifting toward the event horizon but never actually reaching it. (Hey, wait a minute, how then can ANYTHING observable fall into a black hole, if it takes an infinite amount of time to do so from the point of view of an external observer?) In other words, perceptions are radically different depending upon from where you are observing.

And this is sort of the paradox of "complementarity"; one observer sees basically nothing out of the ordinary, while another sees total demolition. And the "solution" to the paradox is that the two observers never get to compare notes. (Hey, wait a minute ....)

In the end, Susskind (and so far, every author or TV show host who has tried to discuss relativity and quantum physics with a lay audience, including Greene and Hawking) has to rely upon his own credibility. I expect that he COULD describe things more completely and with fewer "Hey, wait a minute" moments if he had a chalkboard and could trot out the mathemetics. He could SHOW us why the models and observations and mathematics support one particular view or another. (And truth be told, he gets a little more technical than most authors for lay audiences.) But these details are just too much over the heads of everyone except for those who make a living working with this subject matter. So Susskind has little choice but to report the findings with very little actual explanation, and he asks the reader or listener to trust that he and others have done the actual work to reach this result.

And yet...

Isn't this credibility question largely what The Black Hole War is all about? Didn't Stephen Hawking make a pronouncement, based largely upon his professional stature and credibility (he's Stephen Bloody Hawking, after all!!), which would if true mean (among other things) that the Laws of Thermodynamics weren't really "laws" after all? Good grief, Susskind mentioned a rather large number of people who had to develop models and tinker with the mathematics before Hawking conceded that he did not have good support for his announcement.

And if we can't trust Stephen Bloody Hawking, why should we trust Leonard Susskind, especially when he seems to be speaking out of both sides of his mouth?

 

[DC]

No. Hawking is wrong, and Susskind is wrong. It's like picking sides between catholics and protestants. And besides, this thing has been going since 1981. That's thirty years of drummed-up publicity about a so-called "war". Bah.

and who is correct then? i hope its not just some IT wannabe specialist that doesn't even know the difference between Internet and WWW.

 

[sol invictus]

A person drifting toward an event horizon might not have any sense of anything being amiss and may cross over the event horizon without even realizing it. There's no physical boundary or any tip-off of any change to be detected. (Hey, wait a minute, in the thought experiment where observers dropped a thermometer close to a black hole's event horizon, didn't the thermometer detect a significant change in temperature?)

Only if it's held in place and prevented from falling through. That requires a force and hence an acceleration, and you can think of that acceleration as responsible for the observed temperature. The acceleration required to maintain a fixed separation from the horizon goes to infinity as you get closer and closer to it, and hence so does the temperature. A thermometer that just drifts freely through the horizon wouldn't measure a temperature (or at least not a large one).

They see the person drifting toward the event horizon but never actually reaching it. (Hey, wait a minute, how then can ANYTHING observable fall into a black hole, if it takes an infinite amount of time to do so from the point of view of an external observer?)

This time I'm not sure what the issue is - those two statements are consistent.

In the end, Susskind (and so far, every author or TV show host who has tried to discuss relativity and quantum physics with a lay audience, including Greene and Hawking) has to rely upon his own credibility. I expect that he COULD describe things more completely and with fewer "Hey, wait a minute" moments if he had a chalkboard and could trot out the mathemetics. He could SHOW us why the models and observations and mathematics support one particular view or another. (And truth be told, he gets a little more technical than most authors for lay audiences.) But these details are just too much over the heads of everyone except for those who make a living working with this subject matter. So Susskind has little choice but to report the findings with very little actual explanation, and he asks the reader or listener to trust that he and others have done the actual work to reach this result.

And yet...

Isn't this credibility question largely what The Black Hole War is all about? Didn't Stephen Hawking make a pronouncement, based largely upon his professional stature and credibility (he's Stephen Bloody Hawking, after all!!), which would if true mean (among other things) that the Laws of Thermodynamics weren't really "laws" after all? Good grief, Susskind mentioned a rather large number of people who had to develop models and tinker with the mathematics before Hawking conceded that he did not have good support for his announcement.

And if we can't trust Stephen Bloody Hawking, why should we trust Leonard Susskind, especially when he seems to be speaking out of both sides of his mouth?

That's a very good question. The obvious response is that you must decide for yourself. But how can you - the non-expert reader - decide for yourself, when you only have a badly incomplete and seemingly self-contradictory set of facts to work with? There's no good answer.

Did you at least come away feeling that you learned something interesting or valuable from the book? And if I can ask you another question, how would you change the book to improve it? More technical details? Or just more attention paid to potential "hey, wait a minute" moments?

 

[Farsight]

and who is correct then? i hope its not just some IT wannabe specialist that doesn't even know the difference between Internet and WWW.

The guys mentioned here.

See above where Brown said this?

"Hey, wait a minute, didn't we agree that time is relative and that is seems to slow down from the point of view of an external observer?"

And then sol said this?

"For an external observer, yes. But for the person falling in, those time intervals are finite".

The person falling in ends up with a stopped clock. It's stopped, so his "finite" intervals take forever. So they never ever happen. Let's say that sol is falling into a black hole, and he's holding a light clock. You and I are in our spaceships at a safe distance watching him through telescopes. We have all the necessary apparatus to compensate for redshift and doppler effects. We see his clock running slower and slower as it approaches the event horizon. Then at the event horizon, we that it stops. That means the coordinate speed of light is zero at the event horizon. That means that you, me and everybody else in the real world will agree that nothing else happens to sol. Forever. Until the end of time. Light has stopped, and so has sol. He doesn't see anything any more, and he doesn't measure any proper time on his stopped clock.

Now take a look at this page from Misner/Thorne/Wheeler's Gravitation posted by a guy called Jesse. On the diagram on the left, the curve peaks to infinity at the event horizon. That's the gravitational time dilation tending to infinity, and coordinate time tending to forever. At the top of the peak, is the end of time, so there is no top to it. But it's "transformed away" using Kruskal-Szekeres coordinates. In essence a mathematical conjuring trick is employed to do a hop skip and a jump over the end of time, by pretending that a stopped clock is still ticking away, when it isn't.

 

[sol invictus]

The guys mentioned here.

Trust Farsight to pick an idea that's gotten zero traction since it was proposed nearly a decade ago. Some versions of it (Laughlin et al) are literally impossible, others merely totally unsupported and badly motivated (Mottola et al).

See above where Brown said this?

"Hey, wait a minute, didn't we agree that time is relative and that is seems to slow down from the point of view of an external observer?"

And then sol said this?

"For an external observer, yes. But for the person falling in, those time intervals are finite".

The person falling in ends up with a stopped clock.

As viewed from the outside, yes - although even that isn't quite accurate.

It's stopped, so his "finite" intervals take forever.

As viewed from the outside, yes.

Now take a look at this page from Misner/Thorne/Wheeler's Gravitation posted by a guy called Jesse. On the diagram on the left, the curve peaks to infinity at the event horizon. That's the gravitational time dilation tending to infinity, and coordinate time tending to forever. At the top of the peak, is the end of time, so there is no top to it. But it's "transformed away" using Kruskal-Szekeres coordinates. In essence a mathematical conjuring trick is employed to do a hop skip and a jump over the end of time, by pretending that a stopped clock is still ticking away, when it isn't.

Take a look at this metric:

[latex]$ds^2 = -(r-r_0) dt^2 + dr^2/(r-r_0) + dy^2 + dz^2$[/latex]

Comparing to the Schwarzschild metric near the horizon, you'll see that there is no real difference. Just as for the Schwarzschild metric, you can see at a glance that the gravitational time dilation goes to infinity at r=r_0. So according to you, "really" time stops there, and it's a pointless trick to describe the region behind the horizon (r<r_0). Is that an accurate description of your views?

 

[DC]

The guys mentioned here.

See above where Brown said this?

"Hey, wait a minute, didn't we agree that time is relative and that is seems to slow down from the point of view of an external observer?"

And then sol said this?

"For an external observer, yes. But for the person falling in, those time intervals are finite".

The person falling in ends up with a stopped clock. It's stopped, so his "finite" intervals take forever. So they never ever happen. Let's say that sol is falling into a black hole, and he's holding a light clock. You and I are in our spaceships at a safe distance watching him through telescopes. We have all the necessary apparatus to compensate for redshift and doppler effects. We see his clock running slower and slower as it approaches the event horizon. Then at the event horizon, we that it stops. That means the coordinate speed of light is zero at the event horizon. That means that you, me and everybody else in the real world will agree that nothing else happens to sol. Forever. Until the end of time. Light has stopped, and so has sol. He doesn't see anything any more, and he doesn't measure any proper time on his stopped clock.

Now take a look at this page from Misner/Thorne/Wheeler's Gravitation posted by a guy called Jesse. On the diagram on the left, the curve peaks to infinity at the event horizon. That's the gravitational time dilation tending to infinity, and coordinate time tending to forever. At the top of the peak, is the end of time, so there is no top to it. But it's "transformed away" using Kruskal-Szekeres coordinates. In essence a mathematical conjuring trick is employed to do a hop skip and a jump over the end of time, by pretending that a stopped clock is still ticking away, when it isn't.

wow compensate for redshift AND doppler effects.......

 

[Farsight]

...Just as for the Schwarzschild metric, you can see at a glance that the gravitational time dilation goes to infinity at r=r_0. So according to you, "really" time stops there, and it's a pointless trick to describe the region behind the horizon (r<r_0). Is that an accurate description of your views?

No. It isn't time that's stopped, it's light. So it takes forever to make a measurement, so you can't make any measurements, and as a result there is no actual metric. I guess an accurate description of my view would be to say that variations in the coordinate speed of light are variations in the real speed of light, and that the constancy of the locally-measured speed of light is a by-product of how we use the motion of light to define the second and the metre. Replace "motion of light" by "propagation of electromagnetic phenomena" if you prefer.

I wouldn't say it's a pointless trick to try to describe "the region behind the horizon". Stars do collapse into black holes as far as we can tell, black holes get bigger, there's some very interesting parallels between pulling away from a black hole and the expansion of the universe, and physics and cosmology is so darn interesting.

 

[sol invictus]

No. It isn't time that's stopped, it's light. So it takes forever to make a measurement, so you can't make any measurements, and as a result there is no actual metric. I guess an accurate description of my view would be to say that variations in the coordinate speed of light are variations in the real speed of light, and that the constancy of the locally-measured speed of light is a by-product of how we use the motion of light to define the second and the metre. Replace "motion of light" by "propagation of electromagnetic phenomena" if you prefer.

It's not just light or EM phenomena, Farsight, it's everything. All processes slow and stop on the horizon as viewed from outside, not just EM ones. But for someone falling through the horizon, at least for a large black hole where tidal forces are small, nothing even slightly unusual happens.

I wouldn't say it's a pointless trick to try to describe "the region behind the horizon".

That's good - because the metric I posted describes absolutely flat spacetime. The horizon can be placed anywhere you like, it's a coordinate artifact. Nevertheless, everything you've said about black hole horizons apply to it - so you clearly have to be much more careful when you assign physical significance to those facts.

 

[Farsight]

It's not just light or EM phenomena, Farsight, it's everything. All processes slow and stop on the horizon as viewed from outside, not just EM ones.

Agreed.

But for someone falling through the horizon, at least for a large black hole where tidal forces are small, nothing even slightly unusual happens.

I know that's what they say, but all processes slow and stop on the horizon as viewed from outside. So imagine I'm lowering you down on a gedanken rope. I lower you down a little, and we compare notes through the comms line wrapped around the rope. We note that initially you experience fairly modest gravitational time dilation. Your parallel-mirror light clock doesn't keep pace with mine, a pulsar a few light years away appears to have speeded up, my voice sounds like Pinky and Perky. I lower you further and the gravitational time dilation becomes so dramatic that a minute of your time is an hour of mine. When I lower you to the very near the event horizon you see suns forming flaring and dying in what seems to be minutes, and galaxies racing across the sky then growing dim. When I lower you all the way to the event horizon, you see the whole evolution of the universe happening in an instant.

Or at least that's what you think you see, but think about it. Take any black hole you like in this universe. The observer at the event horizon, regardless of when he started out, hasn't seen the whole evolution of the universe happening in an instant yet. And he never ever will.

That's good - because the metric I posted describes absolutely flat spacetime.

Sorry, I didn't look at it. The thing is, mathematics doesn't get this crucial point across. That's why people blithely switch to a different metric I suppose, and do that hop skip and a jump over the end of time without even noticing.

The horizon can be placed anywhere you like, it's a coordinate artifact. Nevertheless, everything you've said about black hole horizons apply to it - so you clearly have to be much more careful when you assign physical significance to those facts.

I agree that different people will disagree about where the event horizon is located. But a zero or very low speed of light is no artefact. Your coordinate system is. It isn't something real that actually exists. It's an artefact of measurement. And when all processes slow and stop, you can't measure anything. You can't see anything, and you can't even think, because all processes have stopped. So you don't have a coordinate system. Your proper time is being measured on a stopped clock. Just because you're stopped too doesn't mean that nothing even slightly unusual happens. It means nothing happens.