Linde on Inflation and the Multiverse

Andrei Linde is one of Yuri Milner’s $3 million dollar men, best known for his “chaotic inflation” version of inflationary theory, as well as being one of the main proponents of anthropic multiverse mania. There’s a long piece based on a conversation with him up now at the Edge web-site.

Much of the piece is just a retread of the usual heavily-promoted ideology of the past 30 years of fundamental physics research: we must have SUSY, so must have supergravity, so must have string theory, so must have the landscape, so must have a multiverse where we can’t predict anything about anything, thus finally achieving success. Linde claims he pretty much had this picture 30 years ago back in 1982, with the string theory component in 1986, with others coming around to his point of view in the last 10 years, partly because of the KKLT work he was co-author of in 2003.

Besides the tired Stanford pseudo-scientific ideology, there’s also a wonderful history of the subject of inflation, from a Moscow point of view, which is rather different than the Western, Alan Guth-oriented, point of view from which the story is often told. Linde’s description of Hawking’s visit to Moscow is not to be missed:

The next morning after I gave a talk at this conference, I found myself at the talk… oh, my God, this is going to be a funny story… I found myself at the talk by Stephen Hawking at Sternberg Institute of Astronomy in Moscow University. I came there by chance because I have heard from somebody that Hawking was giving a talk there. And they asked me to translate. I was surprised. Okay, I will do it. Usually at that time Stephen would give his talk well prepared, which means his student would deliver the talk, and Stephen from time to time would say something, and then the student would stop, and change his presentation and do something else. So Stephen Hawking would correct and guide the student. But in this case they were completely unprepared; the talk was about inflation. The talk was about the impossibility to improve Alan Guth’s inflationary theory.

So they were unprepared, they just finished their own paper on it. As a result, Stephen would say one word, his student would say one word, and then they waited until Stephen would say another word, and I would translate this word. And all of these people in the auditorium, the best scientists in Russia, were waiting, and asking what is going on, what it is all about? So I decided let’s just do it, because I knew what it’s all about. So Stephen would say one word, the student would say one word, and then after that I would talk for five minutes, explaining what they were trying to say.

For about a half an hour we were talking this way and explained to everyone why it was impossible to improve Alan Guth’s inflationary model, what are the problems with it. And then Stephen said something, and his students said: “Andrei Linde recently proposed a way to overcome this difficulty.” I didn’t expect it, and I happily translated it into Russian. And then Stephen said: “But this suggestion is wrong.” And I translated it… For half an hour I was translating what Stephen said, explaining in great detail why what I’m doing is totally wrong. And it was all happening in front of the best physicists in Moscow, and my future in physics depended on them. I’ve never been in a more embarrassing situation in my life.

Then the talk was over, and I said: “I translated, but I disagree,” and I explained why. And then I told Stephen: “Would you like me to explain it to you in greater detail?” and he said, “Yeah.” And then he rode out from this place, and we found some room, and for about two or three hours all the people in Sternberg Institute were in panic because the famous British scientist just disappeared, nobody knew where to.

During that time, I was near the blackboard, explaining what was going on there. From time to time, Stephen would say something, and his student would translate: “But you did not say that before.” Then I would continue, and Stephen would again say something, and his student would say again the same words: “But you did not say that before.” And after we finished, I jumped into his car and they brought me to their hotel. We continued the discussion, which ended by him showing me photographs of his family, and we became friends. He later invited me to a conference in Cambridge, in England, which was specifically dedicated to inflationary theory. So that’s how it all started. It was pretty dramatic.

Addressing the question of “what evidence is there for any of this?”, here’s what Linde has to say:

Usually I answer in the following way: If we do not have this picture, then we cannot explain many strange coincidences, which occur around us. Like why vacuum energy is so immensely small, incredibly small. Well, that is because we have many different vacua, and in those vacua where vacuum energy is too large, galaxies cannot form. In those vacua, where energy density is negative, the universe rapidly collapses, and in our vacuum the energy density is just right, and that is why we live here. That’s the anthropic principle. But you cannot use anthropic principle if you do not have many possibilities to choose from. That’s why multiverse is so desirable, and that’s what I consider experimental evidence in favor of multiverse.

So, the main experimental evidence for the multiverse is that an anthropic argument works. Some might not find this completely convincing.

About 5 years ago, the field of “string cosmology” was quite active, with even a graduate-level textbook appearing. My impression (contrast the tone of this review, with those of 5 years earlier) is that there’s much less interest in this area during recent years, since it became obvious that no predictions about physics were going to emerge from it. Late this year or early next year the Planck experiment will finally report what it sees in the CMB. I’m curious to know whether Linde and other string cosmology proponents have any predictions for what Planck will tell us.

Update: The Annenberg Foundation funds Annenberg Learner, a site designed to provide information to high school teachers. Their Physics course includes a unit from Stanford’s Shamit Kachru, which is pretty much pure hype, unadulterated by any skepticism that string theory might not be the way the world works. Physicists may have lost interest in string cosmology, seeing it as a failure, but that’s no reason not to teach it to high school students…

Update: Historian of science Helge Kragh has a new article Criteria of Science, Cosmology, and Lessons of History discussing the Multiverse, philosophy of science, and the dubious use of historical analogies. About the Multiverse: “it explains a lot but predicts almost nothing”.

Update: Tonight’s arXiv listings include The Top 10500 Reasons Not to Believe in the Landscape from Tom Banks, which starts off with:

The String Landscape is a fantasy.

He goes on to claim co-credit with Linde for the anthropic explanation for the value of the CC (in inflationary models), as well as to argue that it is wrong:

Linde and I were the first to suggest an anthropic explanation for the value of the c.c. based on inflationary models [2], but within the context of the string landscape, or most any contemporary view of global EI [i.e., Eternal Inflation], I don’t think anthropic reasoning leads to good phenomenology.

This entry was posted in Multiverse Mania. Bookmark the permalink.

38 Responses to Linde on Inflation and the Multiverse

  1. physicsphile says:

    Hi Peter,

    As I understand it there isn’t a unique prediction for Planck from string cosmology or from inflation in general. The main hopes would be that Planck eventually shows some evidence for gravitational waves or primordial non-gaussianity. Either of these should considerably narrow down the possible types of inflation that could have occurred. But unfortunately, if no such evidence is seen the results will still be compatible with many other forms of inflation from and not from string cosmology.

  2. Shantanu says:

    Peter and others,
    just to give credit where its due, want to draw attention to Demos Kazanas paper in
    1980 in ApJ which contained the same ideas of inflation. Its sad that not many people
    cite this paper.
    http://adsabs.harvard.edu/abs/1980ApJ…241L..59K

  3. Mike says:

    Will Planck be able to show evidence of gravity waves from the gravitational lensing of CMB measurements and will Planck actually confirm inflation predictions to a high degree of accuracy?

  4. paddy says:

    Peter sorry for being repetitive and either speaking to the converted or to deaf ears. Any invocation of (or recourse to) a multiverse/anthropic argument is suspect on so many different levels: (a) philosophically it begs the question, (b) logically/probabilistically it makes the inverse gambler’s fallacy, and (MOST IMPORTANTANTLY) (c) scientifically it runs the gamut from being moot to being meaningless.

  5. Peter Woit says:

    paddy,

    I basically agree, although one has to look in detail about exactly what claims are being made in each “anthropic” case. The underlying problem here is not so much the anthropic business, but that people are trying to mask the fact that their fundamental theory is a failed, vacuous theory predicting nothing. They’re invoking a multiverse of different possibilities, but when you ask what their theory says about what these possibilities are, the true answer is that it says nothing, so they are making ad hoc assumptions that things are “equally likely”.

    For a different point of view, Linde basically compares opposition to anthropics to Stalinism:

    ” But what is important is that when we studied inflationary theory, we started asking questions which seemed to be metaphysical, like why parallel lines do not intersect, why the universe is so big. And if we had said, “Oh, my God, these are metaphysical questions, we should not venture into it,” then we would never have discovered the solutions. Now we’re asking metaphysical questions about anthropic principle, about stuff like that, and many, many people tell us, “Don’t do it, this is bad, this is the “a” word (anthropic). You should avoid it.”

    We shouldn’t avoid anything. We should try to do our best to use the simplest explanations possible, or what proves simplest, and if something falls into your hands as an explanation of why cosmological constant vacuum energy is so small, and you decide not to accept it for ideological reasons, this is very much what we had in Russia long ago. That ideology told me which type of physics was right and which type of physics was wrong. We should not proceed this way. Once you have multiple possibilities, then you can have scientific premises for anthropic considerations, not just philosophically talking about “other worlds”. Now we have a consistent picture of the multiverse, so now we can tell: “this is physics, this is something serious.” That was about multiverse and different versions of it.”

  6. paddy says:

    Peter,
    Your last point (with the quotes) actually frightened me when I realized that the implication is that some might then think that there should have been in my post another clause: (d) “politically” ……

  7. physicsphile says:

    Mike,

    If inflation happened at around the GUT scale or higher, Plank may be able to detect the gravitational waves by B-modes in the polarization anisotropy of the CMB. Ground based and balloon experiments are trying to detect gravitational waves on smaller scales which involves trying to remove the B-modes generated by lensing.

    The simplest models of inflation predict a red spectral index and a flat Universe. Planck should be able to confirm these to very high precision.

  8. Shantanu says:

    physicsphile,
    from what I understand, GUT-scale inflation is already ruled out (or constrained) by WMAP limits. The whole idea of GUT is just a daydream.
    shantanu

  9. physicsphile says:

    Shantanu,

    WMAP constrains the tensor to scalar ratio to be r less than 0.36 at the 95 percent confidence level. The energy scale during inflation is 3*10^(16)r^(1/4) GeV and so is constrained to be less than 2*10^(16) GeV by WMAP. The GUT scale is around 10^(16) GeV and so WMAP has not ruled out GUT scale inflation.

    I should also mention that the simplest model, ie canonical single field inflation predicts that Planck should not detect non-gaussianity, isocurvature perturbations, running of the spectral index or departures from flatness. It predicts that there should be a red power spectrum of perturbations which should be confirmed at the 5 sigma level.

  10. anonymous says:

    Tsujikawa’s talk exhausts most of the single-field models people discuss. Shantanu will be pleased to see Kazanas very clearly cited.
    http://www2.yukawa.kyoto-u.ac.jp/~jgrg20/invitedata/I18_tsujikawa.ppt

    For more details on this parameterization, consult e.g. Seery & Lidsey.
    http://arxiv.org/abs/astro-ph/0503692v2

    The bottom line is that f_NL has to be small in any of these models with c_s=1. Unobservably small. The best you can get from the usual CMB methods is f_NL~3. (On paper, Planck is supposed to be sensitive to f_NL~5.) To put that into perspective, you’d have to have f_NL~100s before you could tell it’s there just by looking at the maps. Anything with an observable f_NL would be really weird and tell us a lot. On the other hand, if that happens and we still want to stick to these classes of models, c_s<1 will mean it's that much more impossible to measure appreciable tensor-to-scalar ratio r without an ultra deep delensing survey maybe 10-15 years from now. Large-field inflation like chaotic inflation is actually the experimentalists' best hope right now.

  11. P says:

    “My impression (contrast the tone of this review, with those of 5 years earlier) is that there’s much less interest in this area during recent years, since it became obvious that no predictions about physics were going to emerge from it”

    One of the difficulties in superstring cosmology is that there are many scalar fields, and thus many possible cosmologies – depending on which scalar is the inflaton, there are different predictions. But it’s too strong and ultimately just wrong to say that any one of those candidate inflation scenarios doesn’t make predictions. Axion monodromy, e.g., is a large scale inflation model which is very well motivated in type II string compactifications. This scenario predicts observable tensor modes – see McAllister, Silverstein, and Westphal.

    http://arxiv.org/abs/0808.0706

    Planck data will be out soon and could rule out or in this possibility.

    Cheers,
    P

  12. SUSY says:

    “Much of the piece is just a retread of the usual heavily-promoted ideology of the past 30 years of fundamental physics research: we must have SUSY, so must have supergravity, so must have string theory, so must have the landscape,”

    The chain of reasoning presented above seems “convincing” if SUSY does exist.

    You’ve expressed your skepticism of SUSY extension of SM in BSM physics. Are you also skeptical of supergravity? If researchers and papers are published that shows that supergravity is perturbatively renormalizable, isn’t that strong evidence that SUSY is needed (and leads to the above chain of reasoning).

    BTW Eva Silverstein claims her research on string theory and SUSY would imply SUSY would NOT be found at LHC energies. So it’s little wonder her husband promotes it without any skepticism. I can provide a link if you want.

  13. chris says:

    What is so special about perturbative renormalizability? Ordinary gravity is close to being proven renormalizable nonperturbatively, i find this equally appealing.

  14. Peter Woit says:

    SUSY,

    If supergravity by itself makes sense, that’s one way (another would be chris’s nonperturbative renormalizability of conventional gravity) to break the chain of arguments leading to the string theory anthropic multiverse. I don’t want to start yet another discussion of the problems of quantum gravity. The point is just that if you have a long chain of arguments that leads you to something vacuous, what you have is a reductio ad absurdum, showing that there is some flaw in those arguments. There are plenty of possibilities for the flaw, including the starting point of SUSY.

  15. CU Phil says:

    Chris,

    By “Ordinary gravity is close to being proven renormalizable nonperturbatively”, are you referring to the searches for an RG fixed point that are usually referred to as the asymptotic safety program?

    My understanding of the current state of things there is that there is numerical evidence based on truncations of the ERGE for certain actions, and with certain restricted field content. I think the program is an interesting one, but this seems to be somewhat far from having a proof of a fixed point in 4D for gravity in the presence of matter fields. Am I mistaken about the state of things there?

  16. Peter Woit says:

    CU Phil, Chris,

    I’m sorry, but this isn’t a physics discussion board, and I’m not going to moderate yet another discussion of quantum gravity that has nothing to do with the posting. Best to take this sort of thing to Physics StackExchange or somewhere else.

  17. Bernhard says:

    There is nothing new in Linde´s anthropic argument for the vacuum energy but every time I hear it it amazes me how obvious it is that is can in principle “explain” any number. Anomalous magnetic moment of the electron? Forget a brilliant theory like QED that actually predicts it with exquisite precision. You just need some crap theory where you have a zillion solutions for the magnetic moment and when you realize you just can´t explain the number with your crap theory you invoke anthropic reasoning, after all, the electron must have that anomalous magnetic moment in this universe so that we can exist etc, etc. Really …

  18. theoreticalminimum says:

    On a completely different note: I wanted to throw this out for general interest. Cédric Villani has a book out this month, “Théorème vivant” (Édition Grasset). Villani has by now become a household name in France when it comes to the common perception of the (eccentric) mathematician and the popularisation of mathematics, and this book has been greatly expected by many. He’s also the latest Fields medalist to start a new blog-like website. His colleague at the CMS (Cambridge), Clément Mouhot, also has a blog.

  19. Ly says:

    Roger Penrose once pointed out that there should still be a “horizon problem” for EWSB, since most inflation models postulate that inflation ceases well before the universe cools below the electroweak critical temperature. He seemed to think that large-scale defects left over from that era ought to occlude the light of distant galaxies, contrary to observation. Is it reasonable to expect EWSB defects to behave this way, or be otherwise dramatically visible? The papers I’ve looked at have invariably been irritatingly vague on the subject, when they raise it at all.

  20. John says:

    Peter,

    “Much of the piece is just a retread of the usual heavily-promoted ideology of the past 30 years of fundamental physics research: we must have SUSY, so must have supergravity, so must have string theory, so must have the landscape, so must have a multiverse where we can’t predict anything about anything, thus finally achieving success.”
    Granted, SUSY is the assumption. But if SUSY is discovered at the LHC, then doesn’t it follow that supergravity should be more likely? If gravitons exist, and since every particle has a superpartner, it follows that the graviton must have a superpartner. Hence, supergravity. Now, I’m no expert, but I thought string theory is the UV completion of supergravity. And string theory predicts a multiverse. Though it’s most likely experimentally unverifiable, it’s a prediction nonetheless. And it has the potential to explain the smallness of the CC. That’s why some people are taking the idea seriously. They would absolutely LOVE to test the idea, but they can’t. But that doesn’t mean they’ll stop working on it. They believe string theory is the most promising approach to quantum gravity. What’s wrong with that?

    “So, the main experimental evidence for the multiverse is that an anthropic argument works. Some might not find this completely convincing.”
    But it’s still a possibility that has the potential to explain the size of the CC. For a long time, there was no experimental evidence of planets outside the solar system. Now we’ve detected many of them, and an anthropic argument for the fine tuned conditions for life on our planet makes sense. Certainly, there is no conceivable way to test the multiverse, but it’s still a possibility. Now suppose, in the distant future, we somehow find a way to conduct tests of a future quantum theory of gravity (not necessarily string theory) that has the multiverse as a consequence. Suppose we still have no idea how to test the multiverse portion of the theory. Suppose it pasts all those tests. Doesn’t that mean the multiverse portion gains much more credibility? Gravitational waves haven’t been detected yet, but nobody doubts their existence because GR has been tested so well.

    According to the Annenberg Learner website, the course explores the “frontiers of physics.” One definition of “frontier” that I’ve found defines it as “An undeveloped area or field for discovery or research.” Doesn’t string theory fit that description? According to the website: “The goal is to make the frontiers of physics accessible to anyone with an inquisitive mind who wants to experience the excitement, probe the mystery, and understand the human aspects of modern physics.”

    What’s wrong with that? Frankly, when I was in high school, I wanted to learn more about string theory than condensed matter physics. Also, you can’t exactly teach your interests, Peter, to these kids: representation theory applied to QFT. It may be exciting research on the frontiers, but nobody at that level will understand it and it won’t entice them to study physics. Every section of that course, not just speculative string theory, can encourage the students’ wonder for physics.

    From the ST part of the course: “…theoretical effort to develop a “theory of everything” that brings all four forces under the same conceptual umbrella.” What’s wrong with talking about the “effort” to produce a theory of all forces? He doesn’t mention whether it’s been successful or not, just that it’s an “effort”. He also says, “the string concept has stimulated a great deal of theoretical excitement even though it has no connection to experiment so far.” Is this not true, Peter? He even tells us that there’s no experimental evidence for it so far. He’s misleading nobody. He calls ST “the most promising approach”, implying that there are others. What’s wrong with that? (And yes, ST is the most promising approach so far.)

    Therefore, Peter, when you comment about this description on the website with, “which is pretty much pure hype, unadulterated by any skepticism that string theory might not be the way the world works.” you are dead wrong.

  21. Peter Woit says:

    John,

    I don’t see any point in repeating here the same arguments again about why the string theory multiverse is pseudo-science. Others can make up their own minds about whether teaching failed untestable speculation to high school students as the “frontiers of science” is in either their interest or the interest of the field.

  22. John says:

    Bernhard,

    “Anomalous magnetic moment of the electron? Forget a brilliant theory like QED that actually predicts it with exquisite precision. You just need some crap theory where you have a zillion solutions for the magnetic moment and when you realize you just can´t explain the number with your crap theory you invoke anthropic reasoning, after all, the electron must have that anomalous magnetic moment in this universe so that we can exist etc, etc.”

    QED isn’t a candidate for a quantum theory of gravity/fundamental theory, isn’t it? If, in the distant future, a fundamental, well-defined theory is found that agrees with the experiments done in that future, AND predicts a multiverse, wouldn’t that mean the multiverse has more credibility? It may not completely validate it because you can imagine a fundamental theory that agrees with the experiments and does not have a multiverse, but the conjecture at least gets a little more credible.

  23. John says:

    Peter,

    Do you not agree with the definition of “frontier” that I gave you? If you don’t, why not? If you do, then string theory fits nicely with that definition, wouldn’t you say? QM has been with us for almost 100 years and has been very well tested and is in everything from TVs to smartphones. So it’s not really “frontier”. But string theory is, wouldn’t you agree?

    Also, do you not agree that the quotes I took from the ST unit website contradicts your claim that the page contains information “which is pretty much pure hype, unadulterated by any skepticism that string theory might not be the way the world works.” ? Let me repeat those quotes, in case you forgot:

    “…THEORETICAL EFFORT to develop a “theory of everything” that brings all four forces under the same conceptual umbrella.” He also says, “the string concept has stimulated a great deal of theoretical excitement even though IT HAS NO CONNECTION TO EXPERIMENT SO FAR.”

    And, for all we know, the ST program is not dead yet. There is much work to be done to discern what M-theory really is. Correct?

  24. John says:

    “I don’t see any point in repeating here the same arguments again about why the string theory multiverse is pseudo-science.”

    Peter, please don’t leave me hanging. I wrote so much in those first two paragraphs. I did my best! Please direct me to the pages that show how wrong I am. If SUSY is detected, and if gravitons exist, supergravity should exist, right? And if supergravity needs a UV completion, and if string theory is the only UV completion for supergravity, hence string theory. And if string theory predicts the multiverse, then the multiverse is something worthy of more study. And if a fundamental theory in the future passes all test and it predicts a multiverse, wouldn’t you say the multiverse gains in credibility? (I even heard Steven Weinberg give this argument.) Yes or no?

    Please, Peter, don’t leave me hanging here. Yes, or no?

    Don’t you appreciate the relation between the anthropic multiverse and the fact that many many planets exist? It’s another anthropic argument.

  25. John says:

    Also, Peter, if a high school student gets so excited by string theory that he/she decides to major in physics, but then decides he/she wants to do condensed matter theory and he/she makes significant progress in condensed matter theory, isn’t that a good thing? And, again, the course is about “frontiers” in physics, and string theory is definitely part of the frontiers of physics.

  26. Peter Woit says:

    John,

    Yes, amidst the pages and pages of hype, one hype-filled sentence (“A GREAT DEAL OF THEORETICAL EXCITEMENT”) does have one clause admitting no connection to experiment (“SO FAR”). Whether one clause buried in the pages of hype for failed ideas salvages the whole thing as a responsible project aimed at high school teachers is up to people to decide for themselves.

    And yes, as you argue with Bernhard, if string theorists all of a sudden calculate accurately all the parameters of the SM, using a string theory landscape calculation that implies a multiverse, that would be good evidence for a multiverse. It’s also true that if I discover tonight a wonderful TOE which explains everything perfectly and has no multiverse, that will be evidence against the multiverse. At this point, both of those eventualities seem equally irrelevant: I’m a lot more likely to get run over by a truck on my way home tonight.

    As for your speculation about the smart high school student, what if he or she instead of getting excited about the hype sees it for what it is, decides “frontier science” is BS, and decides to become a lawyer instead of a scientist? I think a lot of that has been happening in recent years….

    I can tell you have a deep and abiding love for this hype. Enjoy, but I’m already wasting too much of my life discussing it, enough for now.

  27. John says:

    “decides to become a lawyer instead of a scientist? I think a lot of that has been happening in recent years….”

    Can you give me evidence of this? How many high school kids do you know?

    “Yes, amidst the pages and pages of hype,” Pages and pages? Can you send me a link to all those “pages and pages”?

    “And yes, as you argue with Bernhard, if string theorists all of a sudden calculate accurately all the parameters of the SM, using a string theory landscape calculation that implies a multiverse, that would be good evidence for a multiverse. ”

    So it’s no impossible, right? It’s still possible for this to someday happen. So what are you complaining about?

    “It’s also true that if I discover tonight a wonderful TOE which explains everything perfectly and has no multiverse, that will be evidence against the multiverse.”

    I totally agree with you.

    “I can tell you have a deep and abiding love for this hype.” I don’t love the hype. I’m just trying to show you that you are wrong. If I’m not allowed to do this, then why have a comments section for your blog?

    Also, Peter, you didn’t tell me whether or not you agree with my definition of ‘frontier’ and whether string theory fits that description.

    You also haven’t given me the websites that goes over the flaw in the logical progression of SUSY –> supergravity —> ST —-> multiverse. Do they exist?

  28. John says:

    “As for your speculation about the smart high school student, what if he or she instead of getting excited about the hype sees it for what it is, decides “frontier science” is BS…”

    But the description of this class specifically says that there is so far no experimental evidence for it. It also specifically says that it is a “theoretical effort”. That’s not hype, that’s honesty. If a high school students decides not to pursue physics even after those disclaimers, that’s his/her problem. Are physicists not allowed to study this? And are people not allowed to show this to high school students? If such a unit is presented in that way (emphasizing lack of experimental support and that it’s still very speculative), it’s much more likely to excite students than turn them off.

    Again, please link to me all those “pages and pages” of hype you saw.

  29. John says:

    “I can tell you have a deep and abiding love for this hype. Enjoy, but I’m already wasting too much of my life discussing it, enough for now.”

    But most of your blog posts are about String Theory hype! And now, suddenly, after responding twice to my comments, you decide that you’re wasting too much of your life? Until the next obscure thing you find on the web that strangely convinces you is hype? I mean, where did you even find this course website? It’s like you’re purposely seeking out this stuff. If you’re wasting too much of your life with this stuff, then just stop posting about string theory hype. I mean it’s like it’s so bad, you’re posting stuff you THINK is hype, when it really isn’t, as I showed above in this particular example (see the quotes from the website). I just don’t get it.

  30. Anonyrat says:

    I’ll give a a course in astrology, that hasn’t been proven yet, but conceivably could be a guide for each and every human being on this earth, and lead them to their true destiny. And maybe some of the high school children will become interested in astronomy instead. Peter, oh , Peter, what is wrong with that?

  31. John says:

    Anonyrat,

    Astrology HAS be shown to be incorrect. You know that. So your example makes no sense.

  32. John says:

    Peter,

    I guess you have no rebuttal for me? Let me know. :-)

  33. Typhoon says:

    Consider the spherical high-school student . . .

    All this pure speculation about what a hypothetical high school might or might not choose after being exposed to ST is analogous to arguments for the multiverse and vice versa.

  34. Chris W. says:

    Astrology HAS be shown to be incorrect.

    No it hasn’t, because it can’t be. Why? Because it doesn’t lay any hard predictions on the line. It always has an excuse. That sounds kind of familiar…

    (It doesn’t mesh well at all with successful theories that do lay any hard predictions on the line, so it is certainly incorrect in that sense, and it makes only trivial use [at best] of mathematical arguments. Obviously astrologers don’t care about any of that.)

  35. John says:

    “Because it doesn’t lay any hard predictions on the line.”

    Astrology does have a prediction. It predicts that your life and/or personality is dictated by the positions of the stars relative to the earth. It has been tested: Take any two people born under the same sign. If their life and/or personality is different from each other, astrology is wrong.

    String theory does have a prediction: it predicts SUSY, though not the energy scale at which it is broken.

  36. DrDave says:

    IF I were to say the following (and I’m not): “There are other universes in the multiverse where astrology has been proven to be correct, and eventually we may be able to detect these other universes. You just need to be patient.” You might be skeptical. The problem is that there is no logical determinant in an open-ended, adaptable universes that is different from the above quote. Once you assume that any universe in a multiverse can be constructed to adapt to data which which is contra-indicative, there is a logic problem which is essentially: no argument can be proved or disproved. People who are tired of the argument simply want some rules, and if “no rules” is the game, then there is basically just an endless loop.

  37. scientific responsibility to the public says:

    “The Annenberg Foundation funds Annenberg Learner, a site designed to provide information to high school teachers. Their Physics course includes a unit from Stanford’s Shamit Kachru, which is pretty much pure hype, unadulterated by any skepticism that string theory might not be the way the world works. Physicists may have lost interest in string cosmology, seeing it as a failure, but that’s no reason not to teach it to high school students…”

    If, by 2020, the LHC at full design energy and luminosity (14TEV) finds no evidence of SUSY after collecting sufficient data, and no other evidence of SUSY is forthcoming, do you think Stanford’s Shamit Kachru and other popularizers (i.e Brian Greene, Michio Kaku, Stephen Hawking) have a public responsibility to say string theory should be treated with skepticism?

  38. Peter Woit says:

    scientific responsibility,

    Actually I think it’s now been a long time that string theory unification is something that should be presented skeptically to the public. I don’t think the failure to find SUSY (or anything else for that matter) is going to make much difference to the people promoting string theory to the public. The Kachru material for high school teachers avoids claiming LHC-scale SUSY as a string theory prediction, and everyone still promoting string theory is now careful to do this, since it is now clear what the experimental bottom line is likely to be.

    Nothing is going to stop continuing attempts to mislead the public, but the physics community is not so easily misled, and is already very skeptical about string theory unification. The negative LHC results will have an impact among physicists.

Comments are closed.