The Black Hole War

Leonard Susskind has a new book that’s now out in the bookstores, entitled The Black Hole War: My Battle With Stephen Hawking to Make the World Safe for Quantum Mechanics. It’s about the black hole information paradox, structured around his story of debates with Hawking over the years on this topic.

Back in 2005 I wrote a review here of his previous book, The Cosmic Landscape, which I found pretty much appalling (and my opinion hasn’t changed). There Susskind deals with the failure of string theory by promoting out-right pseudo-science, of a sort that unfortunately has been highly influential. I’m happy to report that his new book is about 10500 times better. In its 450 or so pages, the string theory landscape, the multiverse, and anthropic reasoning make no appearance, with Susskind sticking to legitimate science. Instead of breathless promotion of string theory as a unified theory, here he is cautious about this, emphasizing repeatedly that he is just invoking string theory as a presumably consistent framework for resolving conceptual problems raised by quantum gravitational effects of black holes:

How do we use String Theory to prove something about nature if we don’t know that it’s the right theory? For some purposes it doesn’t matter. We take String Theory to be a model of some world and then calculate, or prove mathematically, whether or not information is lost in black holes in that world.

He even notes that:

Being called a string theorist irritates me; I don’t like being pigeonholed so narrowly.

The style of the book is often over the top, going on about battles and wars, with chapter headings from Churchill’s history of World War II. As is the custom for books in this field, the fly-leaf copy is pretty much nonsense. But, at a general audience level, Susskind gives a good introduction to lots of topics in physics and to the black hole information paradox in particular. It is livened up with various entertaining color and anecdote, starting with a description of hearing about the paradox from Hawking back in 1983 at a conference held in Werner Erhard’s mansion. He describes discussing black holes with Feynman, approaching him first at a urinal in Pupin, the Columbia physics building, and moving later to the local West End Bar (recently turned into a Cuban restaurant).

He ends not with triumphant claims of victory in his war, but with an appropriate description of the current state of fundamental theory:

Confusion and disorientation reign…. Very likely we are still confused beginners with very wrong mental pictues, and ultimate reality remains far beyond our grasp… The more we discover, the less we seem to know. That’s physics in a nutshell.

It turns out that Susskind is now a fellow blogger, blogging at Susskind’s Blog: Physics for Everyone.

Update: At Backreaction, there’s a new posting explaining what the paradox discussed in Susskind’s book really is, at a level more appropriate for physicists.

Update: Some links to reviews. Paul Davies, Sean Carroll, George Johnson. See here for a review of the Johnson review by John Horgan.

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33 Responses to The Black Hole War

  1. Observer says:

    To whom it may concern,

    I realize that this is a bold question but I dare ask it anyway: do we have any objective evidence from astrophysical observations that Black Holes follow the principles of Quantum Mechanics? If not, what entitles both Hawking and Susskind to start from the fundamental assumption that the physics of Black Holes can be described in a quantum framework dominated by locality and unitarity?

  2. Peter Woit says:

    Observer,

    The questions about black holes being studied here have nothing to do with currently feasible astrophysical measurements.

  3. Bee says:

    Hi Peter,

    Thanks for the review! Sounds as if I should give it a read (when I’m through with the ten books I’m currently reading that is). I’ve tried the Cosmic Landscape, but lost interest halfways and didn’t like the writing style either, so never finished it (though I probably read the epilogue if there was one). Since you mention the urinal in Pupin, I’ve always wondered what a women in science misses just by using a different restroom 😉 (Otoh, I worked at an institute where the Prof used to distribute duties while the men’s restroom, as a result several of the guys started using the women’s restroom, no kidding.) Best,

    B.

    PS: Do we know it’s really Susskind’s blog (or attempt thereof)? I mean, everybody could download a photo and sign with whatever.

  4. anon. says:

    ‘The questions about black holes being studied here have nothing to do with currently feasible astrophysical measurements.’ – Woit

    So it’s analogous (in not being tied to experimental facts) to stringy theories resolving imagined Planck scale physics problems.

    Bee: since imitation is the sincerest form of flattery, a fake Susskind blog would be easily distinguishable from the real thing.

  5. Peter Woit says:

    Bee,

    My personal experience is that I haven’t found any significant networking or mentoring opportunities while relieving myself at the Pupin urinals (or any others, for that matter). But maybe that’s just me…

    The Susskind blog mentioned in my posting is legitimate. I learned about it from information on one of the cover pages of the book. Looks like it’s just a blog associated with an introductory course he was teaching, not clear if he intends to use it for other purposes, for instance to discuss his new book.

  6. Christine says:

    Excuse me for being off-topic. At the end of this interesting news, one reads:

    By continuing their research into the forces of nature, the astronomers also hope to find a window into the extra dimensions of space that many theoretical physicists think may exist.

    But no reference is made on how this could be accomplished in terms of the observational research in question.

  7. Professor R says:

    Thanks for bringing it to my attention. I had a look on Amazon and enjoyed the blurb

    ” an effort that would eventually result in Hawking admitting he was wrong, paying up, and Susskind and t’Hooft realizing that our world is a hologram projected from the outer boundaries of space”. Ah

    One serious point – I don’t like the use of Hawking’s name in the title. While I’m sure Stephen won’t object, it’s a fairly obvious marketing ploy, and can only result in yet more hyping of one particular scientist.
    Hard to imagine Bohr writing a book entitled’My battle with Einstein…” isn’t it?

  8. observer says:

    Peter,

    With all due respect, I disagree with your reply:

    “The questions about black holes being studied here have nothing to do with currently feasible astrophysical measurements” – Woit

    Physics near any Black Hole singularity most likely falls outside the domain of validity of quantum field theory and statistical mechanics, as we know them. Anon. is right when he states that the situation “it’s analogous (in not being tied to experimental facts) to stringy theories resolving imagined Planck scale physics problems”

    Regards,

    Observer

  9. Peter Woit says:

    Observer,

    I don’t see what you disagree with. There are no current or planned astrophysical measurements relevant to seeing what happens at a black hole singularity.

    Susskind is writing about the study of toy models of quantum gravity, he makes no claim to be considering anything that even in principle can be directly compared to the real world (unlike in the “Cosmic Landscape”, where he was advertising supposed potential unified theories).

  10. Christine says:

    There are no current or planned astrophysical measurements relevant to seeing what happens at a black hole singularity.

    Not exactly, but of course rotating black hole solutions to Einstein’s equations can be inferred from the modelling of iron emission line of accretion disks around black hole candidates, see, e.g., here, characterizing the black hole spin.

  11. David P says:

    Dr Susskind explains how physicists think about information theory:

    Go to 01:15:30 in the Perimeter Institute Public Lecture: The Physics of Information: From Entanglement to Black Holes

    http://www.perimeterinstitute.ca/Outreach/Public_Lectures/View_Past_Public_Lectures/

  12. anon. says:

    The black hole information problem is not an “imagined Planck scale physics problem”, for those of you who are worried about that; it has nothing to do with physics near the singularity and can be seen entirely within effective field theory on weak-curvature spatial slices.

  13. Bee says:

    Thanks for the link! It was a coincidence I just wrote this post, it had nothing to do with Susskind’s book. Best,

    B.

  14. George says:

    Why does Susskind accept Intelligent Design Creationism? This was in his Lecture 1. Seems a scientist would, well, be more of a scientist.

  15. Chris W. says:

    George,

    I think you misunderstood Lecture 1. He has been known to declare (suggest?) that, if an multiverse-based anthropic explanation for the values of certain apparently universal quantities left underived within the Standard Model does not work, then we will be forced to fall back on intelligent design as the only alternative. I don’t know how serious this assertion is supposed to be.

    (Leaving aside the essential vacuousness of ID, that is an overstatement.)

  16. hmmm says:

    Susskind was just using a dubious debating ploy, saying in effect that the String Theory Multiverse is not a bad idea, because Intelligent Design Creationism is an even worse idea. It’s a bit like saying Aristotlean Epicycles is not a bad idea, because Planets Pushed Around the Sky by Angels is an even worse idea.

    Astute listeners/readers see through this debating ploy by noting that there are more than there are more than two ideas, and that not being the worst idea is not the same as being the best idea.

  17. hmmm says:

    I have ordered the book. I’m looking forward to it. I tried reading “An Introduction to Black Holes, Information And The String Theory Revolution: The Holographic Universe”, but was completely baffled by it. I might learn some interesting physics from this new book, though I’ll read it with a sufficiently large grain of salt when it comes to the author’s personal opinions, as with any such book.

    However, I am curious about something that maybe physics people might know. Is Susskind actually serious about some of the things he says? He seems funny and entertaining on TV documentaries that I have seen (including one on the topic of this book), but I can’t tell if he’s just pulling people’s leg with what he says. He says that since the String Theory Multiverse idea compares favorably to the Intelligent Design Creationism idea, then the String Theory Multiverse idea must be right! Really? Does such an intelligent person actually believe that kind of logic? He says he at war with Hawking! War? Really? Especially when you compare it to the hyper-polite debate the Susskind had with Smolin on edge.org, why does poor Hawking get war?

  18. Chris Oakley says:

    Hmmm,

    Erm, no.

    Susskind is not actually at war with Hawking, it is just that Hawking is better known than Susskind and Susskind wants to have his name associated with him.

  19. hmmm says:

    Surely if Susskind really wanted to cynically title his book to boost sales he easily could have worked the word “God” somewhere into the title.

  20. anon. says:

    hmmm, I think that Hawking is bigger than God in the publishing industry. According to the Foreword of Hawking and Leonard Mlodinow, A Briefer History of Time, Bantam, 2005, p1:

    A Brief History of Time was on the London Sunday Times best-seller list for 237 weeks and has sold about one copy for every 750 men, women, and children on earth.’

  21. go says:

    >Astute listeners/readers see through this debating ploy by noting
    > that there are more than there are more than two ideas, and
    > that not being the worst idea is not the same as being the best
    > idea.

    As a matter of fact, there really aren’t any better ideas other than the multiverse to deal with things like the cosmological constant problem. Multiverse is a logically allowed, but cheap explanation for the problems of physics. There are no successful non-cheap explanations I know.

    Anyway, Susskind was just being his quirky self, people who pontificate about his “unscientific” attitude to creationism make me laugh.

  22. George says:

    Chris W.

    I do not think I am wrong. Dr Susskind said plainly that, while he preferred Darwin, that those that prefer an Intelligent Designer, that’s fine.

    That statement is clearly providing “his scientific” credence to ID Creationism. This is something no real scientist could ever do. He has lost the battle for credibility in scientific light – his thinking is clearly not lucid.

    His statement is in no way related to physics it was a comment about human evolution or design (as he says is an acceptable alternative view to evolution.)

  23. Peter Woit says:

    Given everything I’ve seen from Susskind, I don’t believe he’s a supporter of the idea that ID is as scientific as Darwinism. He clearly enjoys trying to be provocative and outrageous. In one story he tells in the book, he and Feynman are getting a “Feynman sandwich” at the local deli, and Feynman remarks that a “Susskind sandwich” would be similar, but with “more ham”.

    Anyway, people can watch the video segments involved and make up their own minds, but enough already about this one.

  24. I don’t remember — what is a Feynman sandwich?

    Is it constructed by his path integral formulation of quantum mechanics, his theory of quantum electrodynamics, different from all classical sandwiches because of quantum computation, or extremely small as per his invention of nanotechnology?

    The Feynman sandwich on the largest number of shelves is a volume 2 of the Lecture Notes on Physics sandwiched between a volume 1 and a volume 3.

    All that I remember was the sandwich he had the owner of the topless bar in Pasadena add to the booze menu, after the City shut it down. That was a ham and cheese sandwich.

    Feynman, who liked going there (“after a hard day dealing with oscillating bodies, it’s nice to see some oscillating bodies”), succeeded in keeping the place open a few more months. When the city tried enforcing the anti-topless-bar ordinance, the owner could now say: “we’re not a topless bar. We’re a topless restaurant.”

  25. hmmm says:

    go Says: As a matter of fact, there really aren’t any better ideas other than the multiverse to deal with things like the cosmological constant problem. Multiverse is a logically allowed, but cheap explanation for the problems of physics. There are no successful non-cheap explanations I know.

    By multiverse I am sure you mean the Anthropic Principle. But there are certainly much better ideas than this, for example, Cosmological Natural Selection, as explained by Smolin, Dawkins and others. Susskind knows the arguments. He may not agree with them, but he shouldn’t pretend these ideas don’t exist.

  26. somebody says:

    hmmm said: By multiverse I am sure you mean the Anthropic Principle. But there are certainly much better ideas than this, for example, Cosmological Natural Selection, as explained by Smolin, Dawkins and others.

    The multiverse does not necessarily mean the anthropic principle. In fact your example, cosmic natural selection, is a dynamical (non-anthropic) selection principle in the multiverse. But as it stands, it is more wishful thinking than something concrete. That of course doesn’t mean that it is wrong.

  27. hmmm says:

    Ha! I thought somebody might make that point. (Not you specifically somebody, but somebody!) Yes there are many proposals for why the universe is the way it is, and terms such as multiverse may potentially be ambiguous, although usually the context makes it pretty clear what is meant, as was the case above.

    Anyway, there are ideas that are much better than what Susskind and go mean by multiverse, and they shouldn’t pretend these ideas don’t exist or irrationally dismiss them.

  28. somebody says:

    “Anyway, there are ideas that are much better than what Susskind and go mean by multiverse, and they shouldn’t pretend these ideas don’t exist or irrationally dismiss them.”

    “Much better” ideas? Sorry, I am not sure I know any. There are a lot of wishful thinking/brain-fart level ideas that I know of. But nothing that seems to hold promise for anything concrete (including your favorite cosmic natural selection). Landscape/multiverse is pretty concrete – even though it seems useless for making predictions. But this might be just like field theory: it is useless for making predictions of for example, charges and masses of particles. Its through experiments, not theory, that we fix parameters. Unfortunately, this is an era where experiments are hard.

    There, I have the entire “string controversy” in a nutshell for you. 🙂

  29. hmmm says:

    Re: Chapter 20 of Susskind’s book.

    What’s the deal with Alice’s Airplane and Bonzo Dog Food? Is he describing something conventional and common knowledge here? I hadn’t seen this idea before in popularized physics writings.

    Actually these fractally nested propellors would make for a pretty interesting comical hat.

  30. hmmm says:

    Okay, so the book is fun to read and is educational, but maybe the title should be “The Black Hole storm-in-a-teacup”. Sure, the underlying questions are deep, and Hawking, Susskind and many others have made important contributions, but QT and GR have not been unified, and nothing has been resolved or proved here.

  31. Dorothy says:

    I recently downloaded Susskind’s book from Audible.com and put it on my iPod. I am finding it extremely interesting. Susskind is funny, explains things very clearly. So far, I am about half-way through, I am enjoying it very much. Highly recommended.

  32. Christine says:

    Paul Davies wrote a review of Susskind’s new book, it has just been published in Nature.

  33. anon. says:

    The hyperlink to Paul Davy’s Nature review of Lenny Susskind’s book isn’t working, but the correct link is here:

    http://www.nature.com/nature/journal/v454/n7204/full/454579a.html

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