Stephen Hawking’s Final Paper: How to Escape from a Black Hole • Hacker News Board

Re: Stephen Hawking’s Final Paper: How to Escape from a Black Hole

#11

Post by cyphar » Sun, Oct 28, 2018, 9:41 AM UTC

ben_w wrote: post #10

zadler wrote: post #9

Earlier quoted context omitted.

Isn’t that What he called Hawking radiation? Didn’t think it was news at this point. It’s funny how we talk of information “not being lost” since it’s emitted as radiation... would we be able to decypher anything? If not, it’s still lost.

Hawking Radiation, in its original form, did not allow anyone to learn the quantum information about what went into the black hole — if it was made entirely of photons; or entirely of antimatter; or made of any mix of photons, normal matter, and antimatter… all would be indistinguishable. What’s news is that it isn’t all lost, that the starting state has any influence at all on what comes out. I am only an enthusiast…

> but I get the impression this is as surprising as the discovery of Hawking Radiation in the first place

It should be noted that we have yet to experimentally observe Hawking radiation (it is so low-power we don't have the means to observe it). People talk about Hawking radiation as though it is a discovered phenomena -- it isn't. It's a prediction based on our understanding of quantum mechanics and some thinking about how it interacts with event horizons -- and observing it would help reinforce our understanding of the underlying theories.

Re: Stephen Hawking’s Final Paper: How to Escape from a Black Hole

#12

Post by cyphar » Sun, Oct 28, 2018, 9:52 AM UTC

curiousgal wrote: post #8

I get that Hawking's work is incredible and that he, himself, is an amazing person. But is his work really worth putting him on the same pedestal as Newton?

I have the same feeling, and I think people often mix his personal achievement (fighting a degenerative disease for so long and being a very large mind in the world of cosmology) with his scientific achievements (helping refine cosmology and think about black holes and their interactions). I've read several of his books and papers, and while they are definitely very brilliant, he never produced a Principa Mathematica (even Einstein didn't).

In many ways I would argue that Einstein would be a more apt comparison. Einstein based most of his fundamental musings by identifying issues you see when combining different fields and then using thought-experiments to think about these issues. Hawking similarly operated through though-experiments and trying to piece together different concepts from different fields (though he focused far more on cosmology).

Einstein was a brilliant scientist (obviously), but people often over-complicate his work. In many ways, the real beauty of Einstein's work was just how simple and fundamental it was -- and how un-intuitive the final conclusions are. Newton is a whole different ballgame (even though he was wrong about absolute space and time -- but that conclusion took Maxwell's equations to discover).

Re: Stephen Hawking’s Final Paper: How to Escape from a Black Hole

#13

Post by Sharlin » Sun, Oct 28, 2018, 10:00 AM UTC

curiousgal wrote: post #8

I get that Hawking's work is incredible and that he, himself, is an amazing person. But is his work really worth putting him on the same pedestal as Newton?

Indeed. He is a media darling, was a great science popularizer, and decidedly influential in his own sub-subfield of black hole cosmology, but in the greater context of physics "just another" accomplished researcher. On a purely personal level, of course, his career was quite remarkable given his condition.

Re: Stephen Hawking’s Final Paper: How to Escape from a Black Hole

#14

Post by Sharlin » Sun, Oct 28, 2018, 10:13 AM UTC

cyphar wrote: post #11

ben_w wrote: post #10

Earlier quoted context omitted.

Hawking Radiation, in its original form, did not allow anyone to learn the quantum information about what went into the black hole — if it was made entirely of photons; or entirely of antimatter; or made of any mix of photons, normal matter, and antimatter… all would be indistinguishable. What’s news is that it isn’t all lost, that the starting state has any influence at all on what comes out. I am only an enthusiast…

> but I get the impression this is as surprising as the discovery of Hawking Radiation in the first place It should be noted that we have yet to experimentally observe Hawking radiation (it is so low-power we don't have the means to observe it). People talk about Hawking radiation as though it is a discovered phenomena -- it isn't. It's a prediction based on our understanding of quantum mechanics and some thinking ab…

Indeed no existing stellar-mass-or-above black hole is a net emitter of radiation in the current cosmological era. They swallow cosmic microwave background photons at a much higher rate than they emit Hawking radiation and thus grow slowly even if infalling matter is not present. Indeed, they're the best heat sinks in existence. The universe will be billions of times its current age before the CMB has redshifted enough to become cooler than black holes.

Hypothetical primordial blackholes [1] could be much smaller and hotter, and indeed Hawking radiation could provide one way to detect those that have survived to present day, but as of now none have been found.

[1] https://en.wikipedia.org/wiki/Primordial_black_hole

Re: Stephen Hawking’s Final Paper: How to Escape from a Black Hole

#15

Post by davidwihl » Sun, Oct 28, 2018, 10:23 AM UTC

curiousgal wrote: post #8

I get that Hawking's work is incredible and that he, himself, is an amazing person. But is his work really worth putting him on the same pedestal as Newton?

Thank you. In the same vein, it bothers me that Hawking weighs in on AI/ML when he clearly hasn't written a line of ML code in his life. The popular press picks up on his drivel as if he is some authority in the field leading to unsubstantiated fears and misinformation.

Re: Stephen Hawking’s Final Paper: How to Escape from a Black Hole

#16

Post by [deleted] » Sun, Oct 28, 2018, 10:37 AM UTC

cyphar wrote: post #12

curiousgal wrote: post #8

I get that Hawking's work is incredible and that he, himself, is an amazing person. But is his work really worth putting him on the same pedestal as Newton?

I have the same feeling, and I think people often mix his personal achievement (fighting a degenerative disease for so long and being a very large mind in the world of cosmology) with his scientific achievements (helping refine cosmology and think about black holes and their interactions). I've read several of his books and papers, and while they are definitely very brilliant, he never produced a Principa Mathematica…

[deleted]

Re: Stephen Hawking’s Final Paper: How to Escape from a Black Hole

#17

Post by coldtea » Sun, Oct 28, 2018, 10:41 AM UTC

zadler wrote: post #9

iMuzz wrote: post #2

This was so difficult for me to understand because the author tried _so hard_ to make this sound poetic. Here's what I got.. - For a long time we thought that any information (matter/light) that goes into a blackhole is lost forever and is "corrupted". - Hawking believed this for a long time and said “God not only plays dice, but he often throws them where they can’t be seen." No one really knows _how_ the blackhole…

Isn’t that What he called Hawking radiation? Didn’t think it was news at this point. It’s funny how we talk of information “not being lost” since it’s emitted as radiation... would we be able to decypher anything? If not, it’s still lost.

>Isn’t that What he called Hawking radiation? Didn’t think it was news at this point.

No, that's emitting random particles (or antiparticles) from pairs created near the horizon, where one falls in and the other escapes.

That's not getting the information that falls in out.

Re: Stephen Hawking’s Final Paper: How to Escape from a Black Hole

#18

Post by thx4allthestuff » Sun, Oct 28, 2018, 11:01 AM UTC

Sharlin wrote: post #14

cyphar wrote: post #11

Earlier quoted context omitted.

> but I get the impression this is as surprising as the discovery of Hawking Radiation in the first place It should be noted that we have yet to experimentally observe Hawking radiation (it is so low-power we don't have the means to observe it). People talk about Hawking radiation as though it is a discovered phenomena -- it isn't. It's a prediction based on our understanding of quantum mechanics and some thinking ab…

Indeed no existing stellar-mass-or-above black hole is a net emitter of radiation in the current cosmological era. They swallow cosmic microwave background photons at a much higher rate than they emit Hawking radiation and thus grow slowly even if infalling matter is not present. Indeed, they're the best heat sinks in existence. The universe will be billions of times its current age before the CMB has redshifted enou…

I really want to shout out “infinity billion” right now, but I’m not going to do that because it would be childish and silly. (strains)

Re: Stephen Hawking’s Final Paper: How to Escape from a Black Hole

#19

Post by jacobush » Sun, Oct 28, 2018, 11:22 AM UTC

Sharlin wrote: post #13

curiousgal wrote: post #8

I get that Hawking's work is incredible and that he, himself, is an amazing person. But is his work really worth putting him on the same pedestal as Newton?

Indeed. He is a media darling, was a great science popularizer, and decidedly influential in his own sub-subfield of black hole cosmology, but in the greater context of physics "just another" accomplished researcher. On a purely personal level, of course, his career was quite remarkable given his condition.

And did a fantastic job popularising science. He even was in a Star Trek episode as himself!

It brings a stupid happy smile to my face every time I think about it.

Re: Stephen Hawking’s Final Paper: How to Escape from a Black Hole

#20

Post by gordo4 » Sun, Oct 28, 2018, 11:28 AM UTC

davidwihl wrote: post #15

curiousgal wrote: post #8

I get that Hawking's work is incredible and that he, himself, is an amazing person. But is his work really worth putting him on the same pedestal as Newton?

Thank you. In the same vein, it bothers me that Hawking weighs in on AI/ML when he clearly hasn't written a line of ML code in his life. The popular press picks up on his drivel as if he is some authority in the field leading to unsubstantiated fears and misinformation.

you know he's dead, right? don't think he'll be weighing in on much any more.