Susskind on KQED

Someone wrote in to tell me that KQED this morning had Leonard Susskind on to discuss string theory and his book The Cosmic Landscape. Most of the program consisted of him promoting his usual line about the string theory anthropic landscape and how the fact that string theory is compatible with anything makes it a wonderful and exciting new way to do physics. He claimed that there is no longer a substantive split among bright physicists about the landscape, that the only split is over people’s emotional response to it.

There were quite a few strange things in the interview that have little to do with reality. Susskind repeatedly claimed that string theory has a great deal of experimental support, saying:

More and more the things that string theory seems to say seem to jibe and coexist with the things that physicists and cosmologists see in the laboratory.

Near the end of the interview, when asked to cite some experimental evidence in favor of string theory he said that yes there was a lot of evidence including:

1. The existence of gravity.

2. The existence of particles.

3. The laws of the universe.

Quite remarkably he then went on to announce that QCD is a string theory and take credit for it, saying that string theory was “invented by Nambu and myself as a theory of protons and neutrons, an extremely successful theory of protons and neutrons”. According to Susskind, string theory provides “the whole explanation of protons and neutrons and nuclear physics” and that “heavy ion collisions are best described in terms of string theory”.

One questioner asked him about LQG, which he characterized as a “half-baked theory” that was “similar to string theory but not quite the same” and that “even its proponents hope that it is another way of expressing string theory.”

And what of criticism of string theory? Susskind deals with this with purely personal attacks. The interview began with the following:

Michael Krasny: Let’s talk first of all if we can about string theory since you’re kind of called the father of it and all that, I know you’ve been humble on that score, but it’s deserved. Challenges to it, now it’s being challenged left and right… ill-defined, based on crude assumptions.. tell us.

Susskind: You’re talking probably aout some of the books and blogs that have come out in very very big criticism of it. Well, I think one would have to say that some of it is due to a certain kind of grumpiness of people who…um..

Well, for example, there’s one fellow who failed as a physicist, never made it as a physicist, became a computer programmer, has been angry all of his life that he never became a physicist and that physicists ignore him, so he’s now taking out his revenge by writing diatribes and polemics against string theory.

Somehow I suspect this is about me. For the record I’m a faculty member in the math department at Columbia, in an untenured position with title of “Lecturer”, where my responsibilities include teaching, adminstering the department computer system, and engaging in research. Susskind sounds a lot more angry than I’ve ever been, and I certainly don’t feel that physicists are ignoring me.

He goes on to attack Lee Smolin:

There’s another fellow who has his own theory, I won’t tell you who his name is or what his theory is, but he writes lots and lots of theories and his theories go glub, glub, glub to the bottom of the sea before he even gets a chance to put them out there. Physicists don’t take him seriously, he’s angry and so he’s also writing a book complaining…

Just completely pathetic.

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58 Responses to Susskind on KQED

  1. Peter,

    thanks for the link. Correction: the interviewer’s name is Michael Krasny, not David Krasny.

  2. Holy shit! ST is taking on water fast if Susskind is morphing into Lubos Lite.

  3. Peter Woit says:


    Thanks, fixed.

  4. Hmm says:

    Hey Peter,

    Where are all the promised posts on your brilliant research ideas? We’ve been waiting and waiting and waiting and waiting….Surely you’re bursting at the seams to tell us. Captain my captain, give us poor brainwashed masses a direction of research that will lead to concrete falsifiable predictions for physics, and we’ll follow!

  5. J.F. Moore says:

    Yes, please tell us about your career as a “computer programmer”. What a strange guy. It’s like some people aren’t aware that we are now living in a world where lies are discredited rather easily.

    But are you serious that his second ad hominem is directed toward Smolin? If it’s a joke I don’t get it. If it’s real, that’s just scary. Is he that ego-driven or does he just want to sell his book that badly?

    Is this like the gambling addict who doubles down because otherwise he must admit failure?

  6. Rickkkkkkk says:

    Hmm, Peter has made just as many falsifiable predictions as string theory(well actually more if you count his predictions of various Lubos meltdowns and the like) and as a bonus he’s managed to do so without an attack squad or a hype machine. Well done Peter, bravo

  7. Paul Frampton says:

    My good friend Lenny on radio to promote his book does a good job.
    1. Origin of string theory. My first postdoc was with Nambu starting
    late summer of 1968 when I believe I was first to inform Nambu of the
    Veneziano model. Within a couple of months Nambu had string theory,
    in 1968, but did not publish it. My friends Holger Bech Nielsen
    and Lenny himself did it independently. Chronologically Nambu was first.
    2. Popularity of string theory. While it may be the most likely theory for quantum gravity it is probable there will be no data on quantum gravity for a long time so more particle theory papers should emphasize quantum field theory without gravity, by duality the same theory.
    3. Lenny’s “experimental evidence” for string theory showed poetic license but he was merely agreeing hastily with the interviewer as time ran out!

  8. D R Lunsford says:

    Um, hey Lenny, remember Veneziano?


  9. This interview would be funny if it were not so scary and medi-evil.

  10. hack says:

    Lenny can see his expiration date rapidly approaching and the result is not pretty.

  11. damtp_dweller says:

    “Let’s talk first of all if we can about string theory since you’re kind of called the father of it and all that…”

    Sorry, did I miss the email in which it was announced that Leonard Susskind was “the father of string theory?”

    Regardless of one’s view of the theory, surely that title goes to several people, none of whom are Susskind? I’m thinking along the lines of Polyakov, Michael Green, John Schwarz, and, to an extent, Ed Witten.

  12. deloprator2000 says:

    In a way I understand Susskind. Think about it he considers string theory as his “baby”. He helped bring it into this world, he helped develop it to what it is now, for better or for worse, as such he will have an emotional attachment to it. To see string theory dismantled or criticized especially when you’ve dedicated your life’s work to it, must be very difficult. I could just imagine at the turn of the century a leading “ether” theorist talking trash about some young punk named Einstein.

  13. hack:

    Lenny can see his expiration date rapidly approaching and the result is not pretty.

    If it were just Susskind alone… I am afraid that he is correct in pointing out that all the best and brightest, like Weinberg, Witten, Gross, etc., basically agree with him that there is no way around the swampland. Now we are all condemned to work on the swamp drainage project. Anybody trying to escape (Woit, Smolin, who else?) will be punished.

  14. Chris Oakley says:

    Susskind can say what he likes, but an anthropic Weinberg? That is hard to deal with.

  15. Stalin says:

    physicists that use these indimidatory methods can now prevent a scientific discussion, but will not remain influential after retirement.
    Good luck to Berja Lubos.

  16. Lubos Motl says:

    Lenny’s interview is nice. His description of two critics of physics is more personal than what I usually like, but its content is absolutely true.

    I also think that Susskind’s summary of the situation with the anthropic principle was fair – so “congratulations, Lenny” is the only thing I can say.

  17. MathPhys says:

    Paul Frampton,

    Isn’t true that Nambu wrote a paper, typed it himself in a hurry, as he was about to fly back to Japan, and it was circulated privately at the time?

    I recall an early string theorist saying that the manuscript was so full of typos, they had to guess that Nambu frequently used his left hand shifted to the right, so many of his f’s were are actually d’s, and so forth.

    Does anyone know if that manuscript is still around?

  18. MathPhys says:

    It’s too bad that only Susskind is left to call himself “the father of string theory”, as both Holger Nielsen and Nambu, both of whom are brighter and deeper physicists, are no longer in the limelight.

  19. Chris Oakley says:

    Good Morning Lubos,

    Luckily I did not have a mouthful of coffee when I read your comment, otherwise it would have ended up sprayed all over the keyboard.

    “His description of two critics of physics is more personal than what I usually like”

    I assume that you meant “less” rather than “more”.
    Consult a Czech/English dictionary.

  20. boreds says:


    The statement about Lenny being the father of ST confused me when I heard it a while ago—but I think there is indeed a very early Susskind paper (1969?) on string theory as a model for the strong force. I don’t think it’s listed on SPIRES though, and I don’t know why. I can try and dig out the journal reference but probably other people know it.

    Anyway, he apparently lost interest in the subject for a while.

  21. Stefan says:


    I came across Lubos’s post on N.E.W. on “Mixed States”. I read the criticism posted on his blog (17-page review of N.E.W) – well, most of it anyway; I then posted the following reply:


    Name: Anonymous

    Dear L. Motl,

    You recently posted your commentary on N.E.W. on “Mixed States”. May I request a clarification (and if possible, elaboration) of the following remark:

    “He [“P. Woit”] also assumes that string theory suffers from many problems whose absence has been [??] more or less [??] rigorously proved…”

    When one writes “rigorously” does that imply “more or less”? Exactly what problems were enumerated and how were their absences RIGOROUSLY proved within string theory?


    The point of this exercise was: L. and such like will always bark, does that mean we should suspend our own work to respond to each and every diatribe they may (or can possibly) throw at us?

    I don’t believe he is taken as seriously by his peers as he takes himself… I don’t mean that as an insult or a put-down, but the kind of ranting and raving he seems to enjoy engaging in does little service to the cause of science – or rational discourse, for that matter – as a whole.

    Please ask him to reply to the community asap; if he is unable to do so satisfactorily we should take out that old “crackpot index” and ask him to read it thoroughly before he writes his next review / diatribe.
    [He can write anything he wishes in his blog-journal – that is his own personal column.]


  22. plank says:

    “Well, for example, there’s one fellow who failed as a physicist, never made it as a physicist, became a computer programmer, has been angry all of his life that he never became a physicist and that physicists ignore him, so he’s now taking out his revenge by writing diatribes and polemics against string theory.

    Somehow I suspect this is about me.”

    Maybe it’s about Chris Oakley, given that you are not a programmer by trade.

    Anyway, these comments (personal nature) are irrelevant.

  23. Chris Oakley says:

    Hi plank,

    I wish that your theory was correct, but I doubt it.
    First, Peter argues the case against S.T. more eloquently, more knowledgeably and at greater length. He has, after all, written a book on the subject, and secondly, he has a university post meaning that he is more likely to be taken seriously and will therefore be perceived as more of a threat.
    On the subject of the book, have a look at LM’s 17-page “critique”, which proves (?) inter alia that LM has now mastered the difference between the English and American spellings of the word “colour”.

  24. ksh95 says:

    Things like this are not good for HEP. Unfortunately (or maybe fortunately) the people holding the purse strings are rarely as stupid as some would like to think. And even worse than that, it doesn’t take a genius to see what is happening.

    “…what do you think of the people who criticize your theories…the one guy is a poo-poo head who smells and the other guy is a doo-doo brain with big ears…”

    Any one with half a brain will spot emotional immaturity and non-scientific arguments a mile away.

  25. woit says:

    What was bizarre about the Susskind interview was not his claim that he and Nambu were responsible for string theory, but his claim that they were responsible for a successful theory of the strong interactions, e.g. QCD.

    The thing is, the interviewer didn’t ask Susskind what he thought of the critics of string theory, he asked him what he thought of the criticism of string theory. His failure to answer this, and his decision to instead go for personal attacks on the people making the criticisms, speaks volumes.

  26. King Ray says:

    Peter, excellent blog today. Keep up the good fight!

  27. Paul Frampton says:


    You are confusing two different contributions by Nambu. By origin of string
    theory in 1968 I meant rewriting the Euler B function as an infinite number
    of SHOs. The later contribution in 1970 by Nambu was writing the string action as the area of the world sheet. He did type (with many typos!)
    some notes on that which I suspect is what you remember. That action was
    discovered independently by another Japanese theorist Goto in 1971.

    Yoichiro Nambu is the deepest theorist of my 130 collaborators. I wrote
    one paper with him on string theory in 1970. Writing papers with Holger Nielsen was also remarkable for his exceptional creativity. I have never written a paper with Lenny but have talked with him about physics. We are on opposite coasts!

    Peter Woit:

    Nambu, though not Lenny, did contribute significantly to the birth of QCD.

  28. TomB says:

    I didn’t realise physicists have so much in common with structural engineers. As any structural engineer will tell you there’s only two kinda people – structural engineers and those that wanna be.

    Come to think of it – its like the irish on St Patricks day.



  29. Peter Woit says:

    J.F. Moore,

    It’s not a joke, that second piece really was about Smolin. I didn’t bother to transcribe it, but Susskind went on to make up some extreme statement and attribute it to Smolin, then use it to claim that no one could take Smolin seriously. Standard straw-man argument tactic.

  30. Mahndisa says:

    08 01 06

    I had no idea things were so NASTY! It disturbs me that this type of dialog is occuring when learning should be the goal. Geesh! 🙁

  31. LDM says:

    “Well, for example, there’s one fellow who failed as a physicist, never made it as a physicist, became a computer programmer, has been angry all of his life that he never became a physicist and that physicists ignore him, so he’s now taking out his revenge by writing diatribes and polemics against string theory.”

    The reality is that if Susskind thinks string theory has experimental support, then “failed physicist” is in fact a description of him, since string theory clearly has no such experimental evidence.

    But then again, this goes to the heart of the matter. If Woit is correct, then there are a lot of string theorists, “physicists” if you will, that are not really doing physics.

  32. JPL says:

    “Near the end of the interview, when asked to cite some experimental evidence in favor of string theory he said that yes there was a lot of evidence including:

    1. The existence of gravity.

    2. The existence of particles.

    3. The laws of the universe.”

    My-oh-my! Isn’t the existence of Susskind enough evidence in favor of Strings and all that other “SUSSY kind” of theories? Who needs any more evidence? Give it up…

  33. John A says:

    Near the end of the interview, when asked to cite some experimental evidence in favor of string theory he said that yes there was a lot of evidence including:

    1. The existence of gravity.

    2. The existence of particles.

    3. The laws of the universe.

    I trust you’re not paraphrasing this, but someone somewhere has inhaled when they shoudn’t have…

  34. Pingback: Not Even Wrong » Blog Archive » P. University Press

  35. Another Physicist Turned Programmer says:

    Susskind said: “Well, for example, there’s one fellow who failed as a physicist, never made it as a physicist, became a computer programmer…” I took offence to this because it’s arrogant and assumed that just because somebody doesn’t want to do the physics that’s being done in the market, he/she has failed in physics. More often than not, it is the failure of practising physicists to attract physics graduates with physics research that’s exciting and worth doing. Bearing in mind the low pay and hard work that must be endured by most practising physicists as compared to other careers, a physics graduate often faces a hard choice whether to remain in physics, or to switch career. With the current theoretical high energy physics job market being dominated by string theorists, it’s not surprising that a physics graduate who doesn’t believe in string theory (and other “hot” topics being offered in the physics job market) would choose not to waste the rest of his/her life doing something he/she doesn’t believe in. The “failure”, I believe, lies with the inability of current practising physicists to offer research which is believable. Theoretical physics has lost its way and only the die-hard stubborn believers of the current fads in physics (like Lubos) choose to remain. If this is a measure of their “success” in physics, I want no part of it.

  36. MathPhys says:

    Thanks for the clarification. Do you know if Nambu’s notes (with typos) are available? I know he’s retired since a long time, but is he still in Chicago?

  37. Mark says:

    Peter, thanks for the great post and the link to the interview. The crux of the whole matter seems to me to be where Susskind says: “…quantum chromodynamics is a string theory…” and where in he then connects all of the experimental successes of QCD to string theory in general. While I am aware of some work in this direction, I was not aware that QCD was considered a string theory. Nor that any of its successes could be claimed as “MAJOR successes” for string theory. How close to the truth is Susskind? Do most string theorist agree with him? Or do they have other successes that they like to point to? Thanks again.

  38. Peter Woit says:

    Claiming the experimental successes of QCD as successes of string theory is just absurd. There are no experimental successes of string theory to point to.

    Susskind’s original work on string theory was designed to use it to provide a theory of the strong interactions, but this failed completely. We understand the string theory Susskind was a codiscoverer of, we understand QCD, and they’re quite different theories. After the development of QCD in 1973, many people (including Susskind) worked very hard on trying to find a different string theory, one what would be a dual to QCD. One of the main insights of this period was that of ‘t Hooft, that things simplify at large N (=number of colors), and that this is the most promising case to look for a relation to string theory.

    In 1997 Maldacena was able to come up with a proposed string theory dual not to QCD, but to N=4 (different N, number of supersymmetries) supersymmetric Yang-Mills. This led to a lot of hope that similar techniques would soon lead to a string theory dual of QCD, which is Yang-Mills with no supersymmetries. Nine years later, this still remains to be found. No one has a string theory dual to QCD.

    Susskind is claiming to have the solution to a problem that is definitely not solved, one people have been working on for thirty years.

  39. hack says:

    This is rather amusing: Susskind has borrowed another page from the Motl playbook, apparently editing his own Wikipedia page. He deleted reference to his book’s sales figures, and posted verbatim a lengthy, gushing review of his book.

  40. Paul Frampton says:


    In “Dual Resonance Models” (Benjamin, 1974) Chapter 4 reference 23:
    Y. Nambu, lecture notes prepared for the Summer Institute of the Niels Bohr Institute (SINBI), (1970). I did not keep a copy of this paper which explained the string action. In 1974 I had copies of all the hundreds of papers cited in DRM including it. In 1979 I jettisoned them all when DRM was remaindered and string theory seemed finished. The story does not end there. The same book twelve years out of date was reissued by World Scientific in 1986 and sold three times as many. How to explain that? Nambu moves between Chicago and Japan. He might have a copy.
    Otherwise I cannot help. Sorry! Best regards.

  41. L. Riofrio says:

    “Never made it as a physicist, became a computer programmer..” That failure Bill Gates has written another book? (Disclaimer: The writer took a theoretical physics class from Susskind and received an A.)

  42. MathPhys says:


    I have a copy of the original edition of your book.


  43. Peter Woit says:


    According to the latest version of Susskind’s Wikipedia page, he and Michio Kaku are the co-discoverers of string theory, and his “Cosmic Landscape” book is a #1 bestseller.

  44. Chris Oakley says:

    I am surprised that Susskind’s Wiki page fails to mention his other achievements, i.e. that he

    • Developed a cure for cancer
    • Found the Lost Chord
    • Discovered Penicillin
    • Invented Quantum Mechanics
    • Determined the structure of DNA
    • Invented the steam engine.

  45. MathPhys says:

    I just listened to Susskind’s interview, and I found his claim (near the end) that string theory has had “lots and lots of great successes”, then starting to talk about strong interactions, to be indeed very strange. It is simply technically inaccurate.

    Incidentally, he also claims to be behind 1. the assertion that there is no loss of information in black holes, and 2. holography, both of which are definitely due to G ‘tHooft.

  46. Haelfix says:

    1) The assertion that there is no loss of information in black holes.

    Well, might as well chalk up 80% of the theoretical physicists living at the time when Bekenstein and Hawking made their inroads on blackholes, b/c it was more or less *the* question at the time. Picking one side or the other isn’t exactly a great stride. You might ask who coined the question to begin with. Afaik, that comes from Roger Penrose but I might be mistaken.

    If you want more specific details, I suspect you could pick any number of different authors who tackled the problem.

    Incidentally it is still an open question, albeit one with a number of competing solutions (some of which say involve the the Strominger-Vafa calculations on stringy blackhole mechanics) and the plurality of people feel its no loss.

  47. Paul Frampton says:


    Perhaps you should hang on to it. The 1974 book sold only 1200 but the
    1986 reissue sold 4000+; the 1974 book has been widely stolen.
    To answer your original query, the paper is reproduced in “Broken Symmetry” (World Scientific 1995). To the bemusement of my office mates Nambu would come to my postdoc office to tell me his thoughts.In 1969 he told me the action for the string. The dialogue went essentially like:
    Frampton: ” I have to say it is not completely obvious to me why that is the correct action.” Nambu: “But, Paul, you know very well that the action for a particle is the invariant length of its world line” Frampton:” I understand! It is obvious that invariant area is correct.” It is now discussed in textbooks.

  48. MathPhys says:


    What can I say? Y Nambu is a great man. I wish someday he would write his autobiography, but I think he’s too modest to do so

    I just checked that the Benjamin edition of your book is where I thought it is!

    I also just checked that my copy of “Dual Models”, a collection of Physics Reports, edited by Jacobs and published by North Holland in the 70’s is also where still there.

    I bought it (brand new) for about $6.00 in 1982. There were about 10 copies in the warehouse where I bought it. North Holland dumped the whole edition because it was not selling. I wish I bought the whole lot.

  49. MathPhys says:

    As I leaf through physics reports on string theory from the 70’s, I’m struck by the beauty and depth of string theory, even in those very early days.

    I know that 30 years down the track, it still has no experimental evidence, that it works only in higher dimensions, that something is wrong about susy, that compactification is an unnatural idea, and above all, I’m totally put off by the arrogance and hype of people like Motl.

    But there is something about string theory.

    By comaprison, I’m afraid I find that LQG is not only half baked, as Susskind says, but at most 1 per cent baked. There is just no comparison.

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