In October 1984, it was announced that the Nobel Prize for Physics had been awarded to Carlo Rubbia and Simon van der Meer, for the discovery of the W and Z bosons at the UA1 experiment at CERN just the previous year. This was the capstone discovery in the establishment of the Standard Model of particle physics. The third generation of fermions had already been discovered (the tau lepton by Martin Perl in 1977, the bottom quark by Leon Lederman also in 1977), and the nature of the strong interactions had been elucidated by deep-inelastic scattering experiments at SLAC in the late 1960’s and early 1970’s. Unsuspected by many, particle physics was about to enter an extended period in which no truly surprising experimental results would emerge; subsequent particle experiments have only been able to confirm the Standard Model over and over again, including the eventual discovery of the top quark at Fermilab in 1995. (Astrophysics, of course, has provided substantial evidence for physics beyond the Standard Model, from neutrino oscillations to dark matter and dark energy.)
A month earlier, in September 1984, Michael Green and John Schwarz submitted a paper on anomaly cancellation in superstring theories. String theory had been around for a while, and it had been understood for ten years that it predicted gravity, and was a candidate “theory of everything.” But there were many such candidates, each of which had run into significant difficulties when taken seriously as a theory of quantum gravity. Most people who were paying attention had presumed that string theory would face the same fate, but the Green-Schwarz result convinced them otherwise. A brief article in Physics Today was entitled “Anomaly Cancellation Launches Superstring Bandwagon,” and theorists everywhere jumped to learn everything they could about the exciting new possibilities the theory offered.
So here we are, over twenty years later, still with no surprising new results from particle accelerators (although hopefully that will change soon), and still with strings dominating the landscape (if you will) of theoretical high-energy physics. And still, one hardly needs to mention, with no clear path to connecting string theory to low-energy phenomenology, nor indeed any likely experimental tests of any sort.
In the circumstances, it’s not surprising there would be something of a backlash against string theory. The latest manifestation of anti-stringy sentiment is in two new books aimed at popular audiences: Peter Woit‘s Not Even Wrong: The Failure of String Theory and the Continuing Challenge to Unify the Laws of Physics, and Lee Smolin’s The Trouble With Physics: The Rise of String Theory, The Fall of a Science, and What Comes Next. I haven’t read either book, so I won’t presume to review them, but I think we’ve heard the core arguments expressed on this blog and elsewhere. I’m a firm believer that it’s good to have such books out there; I’m happy to let the public in on our internecine squabbles, just as I’m happy to keep them updated on tentative experimental results and speculative theoretical ideas. It seems unduly patronizing to think that we can’t reveal anything to the wider world until everyone in the community agrees on it.
But I don’t actually agree with what the books are saying. Here is the main point I want to make with this post, trite though it may be: the reason why string theory is so popular in physics departments is because, in the considered judgment of a large number of smart people, it is the most promising route to quantizing gravity and moving physics beyond the Standard Model. I don’t necessarily want to rehash the reasons why people think string theory is promising — I’m not positing an objective measurement of the relative merits, but simply an empirical observation about people’s best judgments. Rather, I just want to emphasize that, when you get right down to it, people like string theory for intellectual reasons, not socio-psycho-political ones. It’s not a Vast String Theory Conspiracy, funded by shadowy billionaires who funnel money through Princeton and Santa Barbara to brainwash naive onlookers into believing the hype. It’s trained experts who think that this is the best way to go, based on the results they have seen thus far. And — here’s the punchline — such judgments could change, if new results (experimental or theoretical) came along to suggest that there were some better idea. The way to garner support for alternative approaches is not to complain about the dominance of string theory; it’s to make the substantive case that some specific alternative is more promising. (Which people are certainly trying to do, in addition to the socio-psycho-political commentating about which I am kvetching.)
That is, after all, the way string theory itself became popular. Green and Schwarz labored for years on a relatively lonely quest to understand the theory, before they were able to demonstrate anomaly cancellation. This one result got people psyched about the theory, and off it went. It’s not a matter of impressionable young physicists docilely obeying the dictates of their elders. Read Jacques Distler’s (absolutely typical) story about how he dived into string theory as a graduate student, despite the fact that his advisor Sidney Coleman wasn’t working on it. In a completely different field, listen to Nobel-winning economist Gary Becker on the response to his ideas (via Marginal Revolution):
“There was a sea change. I began to notice it in the 1970s and 1980s. A lot of the younger people coming out of Harvard, MIT and Stanford were very interested in what I was doing, even though their faculty were mainly – not entirely – opposed to the sort of stuff I was doing.”
This is just how academics act. They are stubborn and willful (even at a charmingly young age!), and ultimately more persuaded by ideas than by hectoring from their elders. And it’s not just the charmingly young — if good ideas come along, supported by exciting results, plenty of entrenched middle-aged fogeys like myself will be happy to join the party. If you build it, they will come.
There’s no question that academic fields are heavily influenced by fads and bandwagons, and physics is no exception. But there are also built-in mechanisms that work to protect a certain amount of diversity of ideas — tenure, of course, but also the basic decentralized nature of university hiring, in which different departments will be interested in varying degrees in hiring people in certain fields. Since the nature of science is that we don’t yet know the right answers to the questions we are currently asking, different people will have incompatible intuitions about what avenues are the most promising to pursue. Some people are impressed by finite scattering amplitudes, others like covariant-looking formulations, others don’t want to stray too far from the data. The thing is, these considered judgments are the best guide we have, even if they are not always right. Green and Schwarz were lonely, but they persevered. If you want to duplicate their success, find a surprising new result! You can’t ask a department to hire people in an area they don’t think is promising, just because it serves the greater goal of diversifying the field overall. Crypto-socialist pinko though I may be in the political arena, when it comes to intellectual life I’m a firm believer in the free market of ideas, and would tend to resist affirmative-action programs for underrepresented theories.
The bandwagons come and go, influenced by both data and new ideas. When I was in grad school in 1990, things were in a lull in fundamental physics generally, and students were escaping to Wall Street and elsewhere. The discovery by COBE of temperature anisotropies in the microwave background re-invigorated cosmology, and attracted a number of bright young theorists. The Second Superstring Revolution in the mid-90’s did the same for string theory. There’s every reason to believe that the LHC will do the same for phenomenology — the leading indicators are already easily visible.
The thing that has kept string theory alive is that interesting results have kept coming, from the 70’s (gravity!), to the 80’s (anomaly cancellation, five critical string theories), to the 90’s (branes, dualities, black hole entropy, AdS/CFT). The last few years haven’t witnessed their own “revolution” (unless you count the landscape), but it would seem a little impatient to give up on that basis alone. If nothing else, string theory is extraordinarily fruitful and robust. Indeed, the AdS/CFT correspondence says you can’t really separate field theory and string theory. Take an ordinary gauge theory in flat four-dimensional spacetime, and make it as supersymmetric as possible without adding gravity. Then make the coupling very strong, and the degrees of freedom rearrange themselves — just as the strong coupling in QCD makes the quarks and gluons rearrange themselves into pions and nucleons — into Type IIB superstrings living in a ten-dimensional spacetime. How amazing is that? It’s not proof that strings are connected to the real world (which, as people sometimes forget, is not manifestly maximally supersymmetric, and does in fact involve gravity), but it’s the kind of rich structure that keeps people optimistic that string theory is on the right track.
Of course, you do have to make the case that your personally favorite approach is a promising one, to the public and to colleagues in other specialties as well as to graduate students. This is not always a job that string theorists have done well. Some of them, I’ve heard rumors, can even occasionally be a mite arrogant. Let’s admit, this is something of an occupational hazard among academics; if universities fired all the arrogant people, the remaining faculty would be stuck teaching twenty courses a semester. And, while I think that an enormous landscape of stringy vacua might very well exist, I think that supporters of the idea have dramatically failed to take seriously the difficulty of actually calculating anything on that basis. Discussions about these crucial issues have all too often degenerated into sophomore-level philosophy-of-science debates, which haven’t done credit to either side. The truth is, we’re not doing science in a new way, it’s the same old way — trying to come up with the simplest possible consistent and coherent framework that explains the phenomena we observe.
And (to add one more “of course”), needless to say we need to keep our eyes on the prize, which really is explaining those phenomena. Sometimes people do get entranced with the math, which is fine, but as physicists the ultimate arbiter of interestingness is a connection to data. String theory hasn’t done that yet, and might not do it for a long while, but in the end will have to, one way or another. It’s hard! But string theory will either progress to the point where its connections to reality become increasingly manifest and specific, or people will lose interest and work on other things. That’s the way the system works.
Update: Interesting reports from the Strings 2006 meeting in Beijing from Victor Rivelles, Jonathan Shock, and Dennis Overbye.
Lee (and B, also) — no, I don’t think that taking ratios of the number of people at meetings and dividing up the resources that way makes much sense at all.
I never suggested that, and I don’t think it’s a good procedure either. I can’t give you a recipe to improve the situation. What I am trying to say is that I am convinced it IS possible to support researchers in way that is more effective than it is now.
But that won’t happen by sitting around and complaining about who wrote in which book/article/blog something insulting about someone (this does not refer to your post).
When we’re talking about “resources,” there are two very different main issues: grant money and jobs. Where grants are concerned, people who work at the funding agencies and serve on review panels do make an explicit effort to take into account diversity of what they are funding as well as pure intellectual merit; at least they did when I was serving on those panels. Obviously, some people will be more inclined to think that sending all the money to their own field is the best approach, but in my experience most people aren’t actually like that.
Fortunately, also in my experience most theoretical physicists are quite intelligent and reasonable people. Did you ever consider that they might just not be aware of the cause, and possible solutions, to the current problems? That’s why I say one has to analyze the situiation, and think about ways to improve it.
Best, B.
PS: I am using MS internet explorer and can’t mark text in the post, I can do so in the comments. I just checked with Safari, in this case both works.
PPS: It’s sad that only MS and Apple survived. I don’t want to see physics research being devided up between strings and loops, no matter in what ratio.
MoveOn,
It sure sounds to me like you’re denouncing a book you haven’t read. “a really malevolent attack on a community of people” would characterize your comments here, but the book I wrote criticizes scientific ideas, not the people working on them.
Dear Prof. Carroll,
Yes I cannot. However, if any of you would claim that he/she is good at programming, I guess I would be able to blame, wouldn’t I? 🙂 😉
Best, Y.
Dear string theorists,
just calm down and look at the big picture. Admit to yourself that your field (following the laws of free market) passed (or still passing) through a bubble expansion and now is about to burst. I am not talking about the bubble of ideas, theories, etc. I am talking about the bubble of public perception, hiring, and funding. There is a full analogy with the recent dot-com bubble. I know next to nothing about strings, but one doesn’t need to be an expert to see this. The dot-com bubble was created not by experts and computer programmers themselves, but by general share-consuming public and venture capitalists who where tricked by the hype. The same with string theory. The role of investing public in this case is played by hiring commitees, funding agencies, and expert panels, who often represent other fields of physics and make their decisions based on the general buzz.
Admit that you were (understandably) overexcited in 1980’s and 1990’s when the great superstring revolutions roared. You promised “the theory of everything”, and you (in particular, Brian Greene and Michio Kaku) publicized this idea to the fullest extent. For some time you, string theorists, were able to convince the general public and panelists that yours is “the only game in town”. They trusted you and wrote you a blank check for a few decades. Now time passed and the blank check has expired (or about to expire). Please understand that these are not deeds of some evil antistringy types like Woit or Smolin. In the absence of deliverables, sooner or later the field would come to the same point even if Peter and Lee didn’t write their books and blogs. Like with the stock market, the public support of your field depends on public perception, and this perception started to change. People became tired of waiting when you deliver the promised “theory of everything”. I fully understand that majority of you, string theorists, never made such stupid claims. Yes, this is true. But it is also true that the public didn’t hear your reasonable voices on the high background of hype. You failed to stop people like Kaku (maybe you even found them convenient at that time?), and this is your fault.
The final straw that made many people (including Woit) angry was when some of your colleagues tried to cheat and instead of promised stringy “theory of everything” they began to sell what suspiciously looks like anthropic “theory of nothing”.
My prediction is that the string bubble will burst. Again, I am not talking about the bubble of ideas, but about the bubble of hiring and grant funding. This doesn’t mean the end of string theory. After all, many dot-com companies that survived 2000-2001 will live happily everafter. This simply means a redistribution of resources, what Lee was talking about. Of course you, string theorists, don’t like this. You would like to have the blank check for a bit longer. Who wouldn’t?
Please understand that Peter and Lee are not your enemies, they are just messengers of the inevitable change. Please appreciate the fact that the message was delivered early and you have some time to make a graceful exit out of this situation. Don’t shoot the messengers.
It’s all a bit fuzzy, isn’t it? How would you guys quantify returns on the investment in string theory research? Presumably there has to be a point where funding ramps down unless [something] even if, say, quantum gravity isn’t better explained by some other approach or even that there isn’t a more promising approach (that might be claiming to solve the problem if only it got some more money). Maybe quantum gravity’s time isn’t now.
Just to chime in. Jacques Distlers series of posts are in my opinion the only plausible and reasonable starting point for a sensible discussion of the merits of different approaches to QG.
You *have* to refute or circumvent that logic in order to be taken seriously, b/c as I see it, they are fundamental and there is simply no way around them. Incidentally they are stated in other equivalent forms in several other places (including famous textbooks on quantum gravity)
That these ideas are obvious to people versed in particle physics, but maybe less so to a GR oriented crowd is irrelevant. It is what it is.
Physics isn’t a laundry list of pseudo political top ten ideas from x field versus y field. It is about what you *cant* do, rather than what you can.
Peter Woit wrote:
He’s made string theory look bad, but his intimidation has also been quite effective. Many people who write to me or post comments on my blog tell me to be careful to preserve their anonymity because they fear attacks from him or from others of his ilk. Often these people are string theorists themselves. Yesterday he managed to bully Christine Dantas into taking down a posting she had put up listing ten achievements of LQG, the most prominent alternative idea about quantum gravity.
Bully? 🙂 (Ok, Webster helped).
Well, I have put the posts back yesterday. There were several reasons why I removed them in the first place, LM being just one of them. It doesn’t matter. I do have a lot of other concerns.
Very good post by Sean Carroll and interesting subsequent discussion.
Best wishes,
Christine
Haelfix,
I though physics was about what can IS hence IS.
And ‘theoretical’ physics of what maybe IS or IS not.
Hence you have more than one: maybe IS and IS nots.
Just like there IS/are more than one (view) of Utopia.
But I agree with the rest of your premise, that the laws of physics are ‘known’ as ARE, only until someone shows otherwise – by arguing a point or concept, or theory. Q
An Introduction to String Theoryby Steuard Jensen.
There have been enough cautionary perspectives offered here to let everyone “believe and know,” the necessary requirements on the issue of string theory?
It is the mantra of sorts, that resonates through all of science, does it not?
Why the “backlash,” is one I’m wondering about too?
Yidun:
Stuard. Hope you haven’t been scared away from the conversation. I know I needed to hear the position of others as well, as those who have listed their opinions time and time again here.
Maybe we can hear more of the feelings(there are consequences to the constant reverberations) of those who wonder also about working within the field of strings? What all this has done to your perspectives about continuing to work in this area in the future?
While John tells Jacque that he had gotten tired of quantum gravity, I wonder, if one can ever leave it?:)
Torbjorn Larsson said, about my complaint about not having any forum in which to get an evaluation/criticism of my physics model:
“… The evaluation you ask for lies implicit in the lack of interest you seem to observe. …”.
No, the evaluation for which I ask is not the silent treatment (plus abuse).
The evaluation for which I ask is substantive evaluation of my model in some detail.
Tony Smith
http://www.valdostamuseum.org/hamsmith/
I agree that such “lack of interest” is an indication that physicists do not want to evaluate my model ,
however,
such
This situation is a risk for any product, even ideas. It’s not uncommon or wrong. In short, I don’t see why the market of ideas is vacuous and not working generally and specifically for you.
The evaluation you ask for lies implicit in the lack of interest you seem to observe
My apologies for the confusing-looking typo-messed-up postscript to my previous post. I failed to delete some material quoted from Torbjorn Larsson’s comment to which I was replying. The intent of my postscript was:
I agree that such “lack of interest” is an indication that physicists do not want to evaluate my model,
however, as I said above, it is not the type of evaluation that I “ask for”, nor is it an indication of that the world of physics is now a well-functioning free market of ideas.
Tony Smith
http://www.valdostamuseum.org/hamsmith/
There is no ‘String Theory Backlash’. In order to understand why this is the case, let me continue where Lee left off.
What is being seriously discussed is how to properly evaluate and diversify imbalances in the portfolio of approaches to advancing fundamental physics beyond the Standard Model and General Relativity.
That’s it. Since I discuss these matters with both Peter and Lee frequently, I believe I can say that I know them both to be focused on constructively answering the question above. Obviously, neither of them thinks that the allocation to String Theory should be taken to anything approaching zero. What earns them spirited criticism is that they are bold enough to ask whether it should be farther away from one.
How exactly for some that got to be a crime against science is an issue I have yet to wrap my head around. But since basic research is very much a ‘public good’, the string theory supporters would do well to realize that this is not merely an analogy to a portfolio. The federally and state supported portion of theoretical physics is not only a portfolio but one held by the public rather and advised by the expert community.
Where this story gets peculiar is that a dangerous economic fantasy appears to have developed within the community of String Theorists. In the most absurd version of this fantasy, only those who are currently funded to work on String related projects are competent to decide the percentage allocation of resources to the String program within fundamental physics.
It is hard to know what to make of this in the ‘marketplace’ of ideas as this has no analog in finance. A portfolio manager is an expert agent who is expected to deliver on the terms in which she or he has attracted (less knowledgeable) investors. That is the basis of what constitutes a fiduciary duty under the law and a ‘principal-agent problem’ in economics. As such responsible fund managers neither request nor expect allocations without:
A) External auditing by outsiders with strictly inferior knowledge of the investments.
B) Complementary allocations to other (preferably uncorrelated) speculative investments.
C) Timely progress reports based on the terms of the investment.
The String enterprise has attracted critics precisely because it has been rather timid when it comes to self-criticism. Imagine what Jaques or Lubos could do to best Peter if they really put their minds to it. What a vote of confidence that would be in the string enterprise, to reassure those without expert knowledge that string theorists were their own harshest critics.
So let me challenge the String Theorists to help those investors with deep concern about their investment in fundamental physics:
A) Which independent experts who are not working on string related work are competent to review your percentage allocation and suggest whether it should be higher or lower? How can you help us get around the problem of String theorists commenting positively on themselves and negatively on those who are less informed?
B) What allocations would you suggest for the other programs? LQG? For new programs by younger and less-established physicists and mathematicians? For non quantum-gravity, non-SUSY, extensions of the Standard Model?
C) Can you review the original terms under which the current allocations were made and give us a progress report highlighting any situation in which expectations and performance were significantly mismatched?
In summary, the so-called backlash is actually limited to a nonsensical view of resource allocation which keeps the marketplace of ideas from being fully efficient. That is an economic backlash, not a physical one.
If string theorists wish to keep or even boost their percentage allocation, there is likely no better way than to start aggressive self-critiquing and stop talking about what ‘smart people’ believe when what you mean is ‘string people’.
It’s been 20+ years since the cancellation result which is plenty of time in even the most difficult of subjects for outsiders to observe a speculative program’s performance and benchmark it against expectations.
Hopefully,
Eric
Tony, this is the problem caused by mainstream speculation: the groupthink which asserts one speculative system without any empirical evidence for it, is the same groupthink which is not interested in alternatives.
The reason speculative M-theory based stuff – instead of your 26 dimensional string theory work – is taken seriously is because of the doctrine “might is right”. It doesn’t make one dot of difference whether you predict things and M-theory doesn’t.
The people following M-theory are doing so because they believe so many people can’t be all wrong. It’s religion.
Hi,
Thanks to Sean and everyone for this discussion. Eric said most things better than I could so let me just comment where necessary:
To Moveon: “And hype as well – wasn’t there even an embarrassing press conference called by Lee Smolin a while ago, with the claim that certain observational data would support his theories?”
I have never in my life called a press conference or sent out a press release. I’d be grateful to know where you got this piece of mis-information.
What I have done is tried to communicate, in technical papers as well as public talks and essays work by phenomenologists that shows that results of Auger, GLAST and other planned experiments may be able to distinguish Lorentz invariance, lorentz symmetry breaking and deformations of Poincare invariance from each other at Planck scales. I have also written one paper that argued on heuristic and semi-classical grounds that LQG should predict the third option, but I have been clear that there is rigorous support for this only in results on 2+1 gravity.
To Sean, “Get an exciting physics result that persuades people who are now working on string theory that they should switch to something else.”
Of course I agree and spend most of my time doing this. But there is a rather high barrier of communication to cross because it remains the case that many string theorists simply are ignorant about other approaches. A very prominent string theorists recently said to me, “Oh, is there a path integral approach to loop quantum gravity?” showing that this very good scientist has missed the main results and directions of the field the last ten years. At his renowned institution, as in several others I visited recently I gave the only talk they have had about non-string approaches to quantum gravity for at least the last 5-10 years. This is compounded by the fact that, once again, there are no talks about alternative approaches at the major annual string meeting. (In contrast to the fact that at LQG meetings we always invite people to report on alternatives, including string theory.)
So I insist, there are exciting, substantial results in non-string approaches to quantum gravity that, with a few exceptions, many string theorists and high energy theorists remain ignorant about. But why not try an experiment? Invite some of the leading people to give talks next year-I’d be happy to give you a list. I am willing to bet that at least some of your colleagues will be surprised, impressed and interested.
As to what to do, some proposals are very simple and I discussed them already in my Physics Today Essay. For example, develop an ethic and expectation that if a department or agency invests heavily on one of several rival research programs aimed at resolving a key issue, it also invests in the others. Aim to create groups composed of people working on rival approaches rather than all on the same approach, because this leads to better work and faster progress by everyone. Alternatively, aim to hire the best person working on a particular problem, without regard to research program, and weigh originality and intellectual independence heavily in the evaluation of quality.
Thanks,
Lee
Haelfix #82:
Just to chime in. Jacques Distlers series of posts are in my opinion the only plausible and reasonable starting point for a sensible discussion of the merits of different approaches to QG.
The problem is that when somebody comes up with a solid scientific argument, string theorists suddenly lose interest. I once pointed out to Lee Smolin here, an infinite-dimensional constraint algebra generically acquires anomalies. Lubos evidently appreciated this observation, since he used the literal quote here (Lubos was of course unaware who the original source was, otherwise he would have repeated his usual “gauge symmetries are a redundacy of the description, you idiot” rant). Some string theorists have independently made essentially the same claim, e.g. Urs Schreiber and the authors of hep-th/0501114, in section 6.1.
However, my point with this statement was that in any putative theory of 4D quantum gravity, the constraint algebra (the 4-diffeomorphism algebra or the physically equivalent Dirac algebra) must exhibit anomalies, except perhaps for exceptional values like D=26. Whereas string theorists generally seem to agree with me as long as the argument can be used to discredit LQG, they completely lose interest when I point out that string theory does not allow for diff anomalies neither (nor does field theory proper btw).
For a discussion of why, and which kind of, gauge symmetries must admit anomalies, and a sketch how observer-dependent anomalies arise, see math-ph/0603024.
theory does not allow for diff anomalies neither
in 4D.
The many things in physics that are demonstrably correct all have in common that, in the end, they just “feel” right. This is the aesthetic judgment that makes a good physicist, just as a good ear makes for a good composer, an eye for line and color a good painter, etc. Nothing that is true in physics ever “feels” wrong.
String theory is wrong first of all because it is monstrously ugly. Nothing with such a form could possibly have anything to do with the real world. Its hideous form originates in the arbitrary substitution of one type of source term (point particles) by another. Clearly point particles don’t work – in fact the entire structure of field equations with source terms is what needs to be fixed. The ugliness of string theory comes from the instant realization that one has not only failed to introduce anything really new, one has taken the old flaws and covered them with cheap makeup.
I don’t know why this judgment is so lacking in current researchers. It has nothing to do with being smart – we’re all technically smart enough to do whatever is required to make progress. What is missing is what people like Dirac and Feynman had, a “fine seinse for physical realities” (Pauli) that leads to the right question. Pauli said of Dirac “he finished his argument before it was started” (prediction of antimatter).
The thing that is missing in science is physical intuition. Until that is restored to a prominent role, no progress is possible. I think the stringers chase their chimera so vigorously because to admit defeat means admitting they lack the one thing you can’t do without, and can’t be taught – good intuition.
-drl
I have always appreciate the synoptic evaluations Three Roads had offered the public, as a state of the nation address, to which it served to get everyone up to date with what was happening in research on quantum gravity.
It seems that what can happen in one place(alienation, no acquiesence to model evaluation) is not likely to happen in another?
While one is being careful to direct society, and speak about the public interest, then it can in a sense become the “same operation,” while defending what one thought a persecution in one area, a “resulting action” in another?
So you look for signs of this? Just to be “careful” this is not the case. If this is “directing away” from the issues, then what went wrong with how “we defend our positions” in a public way?
I like leaders of science who debate, and who shall these be? If the arguments are not persuasive, then has the status changed?
Porfolio distributions, I had always thought are based on percentages of returns and the risk? So you assign monies accordingly to the amount of risk you want to take?
Such “evalutions in the industry” are common from what have seen from scientists like JoAnne or John Ellis when it comes time to asssess the direction scientists are going? Assign “money” from the public’s interest?
Is this assessment not correct? That “a body” can control where the public interest are not upheld?
I alway appreciated Perimeters “basis of developement,” and the careful attention this institution has for inviting all to share diverse perspectives. I believe all universites are respective of this way as well?
John Baez-Week 222:
John Barrett of course, may have another way to assess quantum gravity?:) I am sure people are not ignornant of these “ways” as long as they are brought out there to the blogosphere for perspective?
Introduction to String Theory by Gerard ‘t Hooft
Eric and Lee, thanks for your comments. Very briefly now, as I have to rush off–
1. I think it would be great if string theorists had a few talks on alternative approaches at their meetings. In fact, I’d be happy to see physicists in general be more open to listening to work slightly outside their specific fields of research. As a member of the scientific organizing committee for the last couple of triennial GR meetings, I’ve done my best to convince people that it would be good to have (for example) talks on both cosmology and string theory. With some success, although against considerable resistance.
2. The world where string theorists get to decide how much money string theory gets sounds like a bad idea, but doesn’t sound at all like the world we live in. If I look at the department chairs of big universities, a vanishingly small percentage of them are string theorists. Likewise for program officers at NSF and DOE. Where are all these string theory mandarins controlling their own purse strings?
3. Which leads me to reiterate once again my point: people are not “string theorists” (or whatever) by nature, but by choice. Departments don’t invite speakers, and funding agencies don’t allocate grants, and universities don’t hire faculty, on the basis of advice from a cabal of powerful string theorists. You can affect all of these processes by getting results that actually do excite people — you can even get people who have been working on string theory to switch to doing something else. That’s what happened with string theory itself, and that’s what will have to happen for any particular alternative to become popular.
Eric Weinstein wrote:
Do the measures you suggest apply to other research activities, or just to string theory?
Do you see a broad flaw in the existing review process used by the NSF, the DOE and other funding agencies? Or is string theory somehow a special case of a funding anomaly that needs to be dealt with on an ad-hoc basis?
Second, why do you think that “non quantum-gravity, non-SUSY, extensions of the Standard Model” are being under-funded at the moment? (Relatively! In absolute terms, everyone is under-funded these days.) Seems to me that’s an area that is receiving — perfectly appropriately — a lot of attention and support these days.
Thomas Larsson wrote:
Considering the amount of time of time I’ve spent discussing your ideas with you in various fora over the years, “lose interest” is not an accurate characterization. “Think you’re wrong (and given arguments why I think that)” would be more accurate.
But, since there’s already a long list of people in this comment thread complaining “My great idea is being ignored/suppressed by the String Theory Cabal!” you’ll understand if I decline to pursue that particular discussion further here.
That ended the day that uncertainty became a eh, “mechanism” for causality. Then space began expanding faster than light, and now people don’t even know what intuitive physics looks like when they see it!
Feel the collective hmmmmmm… er, duh… *scratch head*:
http://www.lns.cornell.edu/spr/2006-03/msg0073465.html
http://www.lns.cornell.edu/spr/2005-06/msg0069755.html
http://www.lns.cornell.edu/spr/2006-02/msg0073320.html
Maybe people will finally start to wake up after the great quantum gravity crash of 2016?
And don’t even get me started on willful ignorance…
Island,
Neither the equations of quantum mechanics nor Alain Aspects experiments disprove causality proper or prove Copenhagen philosophy/politics/religion. So please don’t throw that around here.
Dr Thomas Love has proved that the entanglement philosophy is just a statement of the mathematical discontinuity between the time-dependent and time-independent Schroedinger wave equations when a measurement is taken. There’s no evidence for metaphysical wave function collapse in either the authority of Niels Bohr, the Solvay Congress of 1927, or Alain Aspect’s determination that the polarization of photons emitted in opposite directions by an electron correlate when measured metres apart.
Accept that Copenhagen quantum mechanics is speculative. Don’t build it up as a pet religion. The uncertainty principle in the Dirac sea has a perfectly causal explanation: on small distance scales, particles get randomly accelerated/decelerated/deflected by the virtual particles of the spacetime vacuum. This is like Brownian motion. On large scales, the interactions cancel out. If so, then photon polarizations correlate not because of metaphysical “wavefunction entanglement” but because the uncertainty principle doesn’t apply to measurements on light speed bosons, and only to massive fermions which are still there after you actually detect them.
Jacques Distler:
AFAIK, you have never claimed that one could exploit the fact that the free string is 2D gravity to learn something about 4D QG. Others have. It is undeniable that Lubos used my literal argument to punch Lee.
The detailed argument can be found in my paper, which is quite able to stand on its own.
Thanks Science, and I understand the application of the Schroedinger wave equations the same way that you’ve graciously explained it, but I was referring to stuff like, Hartle-Hawking, in context with these kinds of widely accepted assumptions that aren’t *really* open to review, even when given new physics…
I apologize for any disrespect that may have come from anything that I may have failed to properly convey.
My reference to the Dirac Sea is about a whole nother way of doing QG, that doesn’t look too much like the current “attempts”… but it doesn’t conflict with relativity and it does appear to be renormalizable if you don’t mind “Large Numbers”.