According to the New York Times, Scarsdale High School has decided to get rid of their Advanced Placement classes, including AP Physics, replacing them with a new curriculum that cost “$40,000 to bring in 25 professors from Harvard, Yale, New York University and other top colleges.”
“We have the luxury of being able to move beyond the A.P.,” John Klemme, Scarsdale’s principal, said in a recent interview. “If people called it a gold curriculum in the past, I refer to this version as the platinum curriculum.”
What’s the change in this new “platinum curriculum” as far as physics is concerned?
Physics students now study string theory — a hot topic in some college courses that is absent from the Advanced Placement exam.
It’s a smart move. By the time these kids graduate, investment banking will be in vogue again.
…I assume this is an “ideas in physics” type of course they’re running, with no math? Because if they aren’t even doing AP Physics, how the hell are they doing String Theory? Even the simplest non-popular accounts require quantum mechanics…
The NY Times article doesn’t really offer enough information to draw any firm conclusion. I’d guess that the regular physics course is spending a few weeks at the end sketching contemporary topics, and that this has been sexed up to “studying string theory” for the purposes of the article.
Like this site, the high school classroom is not “a place for people to promote their favorite ideas about fundamental physics.”
Charles and A.J.,
I couldn’t find a syllabus on the Scarsdale site for the physics class, so I don’t see support for either of your conjectures. It seems that what this is all about is that many high school teachers are unhappy with being forced to teach to a rigid syllabus set by the AP exams. These new courses are meant to replace AP courses, with the students often taking the corresponding AP exams anyway. So, presumably this is not a “no-math” course. No idea how much time they devote to string theory, hard to believe it’s a huge part of the course.
One does wonder whether teaching string theory in a high-school AP-level class is the idea of the Scarsdale physics instructors, or the consultants hired by the school district.
Folks, I think teaching “string theory” – whatever that might mean in high school – is really besides the point. Scarsdale deserves praise for phasing out the ridiculous AP curriculum and actually teaching kids something meaningful beyond how to, you know, memorize facts and best use practice exams. Besides, pretty much every reasonable university has ‘exposure’ courses in something like string theory/complexity theory/what have you.
Rob,
If Scarsdale wants to abandon the set AP curriculum and do something better, that’s fine. But, if their idea of something better is to feed trendy hype to their students instead of solid science, which is what they are doing if they are replacing conventional topics with “string theory for high school students”, then that is educational malpractice.
Peter,
If I had to guess, I’d say that they offered up “string theory for high school students” as a sound bite for the usual bad reasons. If they are indeed teaching a ‘Scientific American-esque’ course on string theory, rather than a fancy sounding low-level physics or mathematics course – yes, that’s a serious issue. That said, I don’t see a problem with something like an optional lecture series on the topic (not that kids are going to get anything out of it).
They should teach a good course on quantum mechanics or stat mech. It (1) – would sound catchy, (2) – would be accessible enough for high-schoolers, and (3) – would be really useful for most future scientists and engineers.
Rather, the knowledge in those areas would be “…really useful for most future scientists and engineers.” I have some doubts about a class for high school students.
I can’t imagine this working, at least not without some serious changes to the whole curriculum. As I recall, AP Physics was a constant struggle for the teacher to teach the calculus the students should have received in their math classes.
I don’t really understand the scorn that is heaped on the AP curriculum, especially in physics. It seems that a lot of it comes from people who never actually took an AP class? In my view, it’s a fairly solid curriculum which covers basic mechanics and E&M. And it was a challenge to fit all that in one school year. The exam isn’t bad either, and unlike the dreaded GRE actually has some questions which aren’t multiple choice.
I think a lot of it has to do with the quality of the instructor, and the lack of high school teachers with dedicated physics backgrounds. I was fortunate enough to go to an excellent (public) high school, which had one of the only two teachers in the STATE who were certified to teach actual physics, not just “science”. I was also fortunate enough to take an International Baccalaureate (now that really ought to be the “beyond the AP” curriculum, but that’s a whole other discussion) physics class after AP which went over waves, stat mech, and some basic quantum.
That’s the sort of thing students need: an AP class to teach the basic fundamentals and only after that classes that teach more contemporary topics.
I doubt they’re getting more than a day or two of string theory.
Just for background, Scarsdale is one of the best public high schools in the country, and has long employed PhDs to teach their math & science classes.
Students there have structured their lives to be attractive to good schools, so if this change somehow harms test scores or admissions rates it will immediately vanish.
As an aside, at different times my wife has been a director of a neighboring school board and the chair of our local school board. Her experience is that many parents are obsessed with high math & science marks for their children but most do not actually value what their children learn in these classes. There is constant pressure from parents, teachers and students to dumb down these subjects so students can get better grades. In her experience, individual weak teachers are not the focus for most parent complaints. As long as the students get good grades everything is OK with most parents. Tough teachers or tough exams are the flash point for almost every crises my wife has faced concerning these subjects. I am sure there are some over-the-top teachers & exams but it is strange that my wife has never received a complaint about a teacher or exam that doesn’t challenge the students enough. How relevant this point is to the discussion I do not know but I do know science and math is constantly under attack in our public schools.
Jack Lothian,
This exact same thing has been happening in community colleges too. Students and their “helicopter parents” will revolt and try to get the tough instructors fired. Frequently the tough instructors will get several reprimands from the administrators, before eventually being fired for being “too tough”.
Though back to the subject, string theory has not been mentioned at all in the physics courses taught at community colleges. (Not even by instructors who are believers in string theory).
They are teaching string theory to high school students? Oy! What is the woild comin’ to?
The string theorists are really getting desperate. I always thought that contemporary theoretical physics was beyond the grasp of even many of the brightest high school students. To truly understand and appreciate Newtonian physics, one needs a background in calculus, and most American high school students do not learn calculus until senior year if at all. (The concepts of Newtonian mechanics are simple enough that calculus or any higher math is unneeded. Entry-level algebra would suffice, but to get a good working understanding requires analytical geometry and calculus and the like.) Not to mention such 20th century theories as quantum mechanics or relativity theory.
To truly understand higher physics would require not only advanced algebra, analytical geometry, probability, statistics, calculus, etc. but discrete mathematics, matrix operations, linear algebra, differential geometry, and the like. High school students should be able to understand the basics of quantum theory, especially as it applies to chemistry, but relativity requires very advanced geometries! Relativity would not make sense within Euclidean geometry. To say nothing of string theories with the many warped dimensions…
As I understand it, AP type physics courses generally cover advanced Newtonian physics with introductory lessons on relativity and quantum physics. They might explain what special relativity postulates or the meaning of E=mc^2 for instance. A high school level course might be set up as “Fundamentals of Modern Physics” (i.e. quantum theory, relativity), but without the math and physics background, such courses would be pop-sci introductions. Such an approach would be acceptable for more established theories such as relativity or quantum mechanics, but it would be a bad idea to apply said format to controversial theories like string theory and its variants. If you ask me, assuming it is true that high school students study string theory, it looks like these kids are being indoctrinated into the string cult.
Regarding what Thomas R. Love said, it seems apparent to me that he is a disgruntled string theorist displeased with your blog. After all, he accuses you of censorship, claiming, “[this site] is not a place for people to promote their favorite ideas about fundamental physics,” implying that you stifle dissenting viewpoints. While I support his right to comment, I would disregard that statement. Dr. Woit, your blogging does a great service to the physics community. Keep up the good work!
Jake,
Thomas Love is not a string theorist. I certainly do stifle certain kinds of dissenting viewpoints, ruthlessly censoring comments that are off-topic and go on about the author’s favorite ideas. On the whole, I think people appreciate this policy…
I don’t think we can put too much stock in an article that describes string theory as “a hot topic in college courses.”
Jake the Snake: the phrase: “a place for people to promote their favorite ideas about fundamental physics.” occurs just below “Leave a Reply”.
I was just quoting Peter. His book is a must read for any aspiring physicist.
To call me “a disgruntled string theorist” is an insult. I do mathematical physics. String theory is not physics. It is not even sound mathematics.
I agree that it would be horrible to feed the kids Kaku-style nonsense. But if at all they are to hear *anything* about the frontiers of theory, it is reasonable that they hear about string theory. The most reliable judge here is the consensus of the scientific community (NOT consensus among ignorant haters, like we have on this thread). Even if we believe that Peter is a messiah who could look into the future, at this point in time, the reasonable thing to teach kids is the consensus of the community, not the views of a minority of dissenters. The discussion here would have more content, if it focussed on the hype aspect rather than on teaching string theory altogether.
somebody,
I agree with you that the consensus of the scientific community should be a deciding factor here. This is not the same thing as the consensus of the string theory community. From talking to many, many scientists, my impression is that the consensus of the scientific community is that the picture of unifying particle physics with strings in extra dimensions is a very speculative idea that doesn’t seem to be working out. This is not what “dissenters” think, this is what most physicists who are not string theorists think. Even among string theorists, I see an increasing number who have given up on string theory for unifying particle physics, instead seeing it as a tool for studying strongly coupled qfts, and as a toy model for understanding issues in quantum gravity.
There are several different problems with the idea of teaching string theory in high school, but one of them is precisely that the speculative picture of unification still vocally promoted by an increasingly small number of physicists does not have support from the rest of the scientific community.
To Peter Woit and Thomas. R Love, I apologize for the misunderstanding.
Mr. Love, I’m sorry that I misunderstood your above comment. I was not aware of your meaning as you did not provide the context. I did not know it was a Woit quote. I thought you were insinuating that Woit CENSORS differing viewpoints (i.e. string theory), as opposed to applying skepticism to FILTER out bad ideas, and you were implying that he similarly wanted to keep string theory out of the classroom for ideological reasons.
I took you for someone on the side of Lubos Motl, not our side. As it turns out you are not a string theorist (thank you for clarifying) and, the quote in context means that the classroom, like this blog, should be “no-nonsense zones.” What I took to be anger or displeasure at string theory being excluded was in fact agreement that certain ideas are not appropriate. Correction appreciated!
Dr. Woit, I appreciate the reply. First off, this is your blog and your right to moderate comments. I do not believe what you do is “censorship” so much as “filtering.” I agree that irrelevant and off-topic comments, or messages that are disrupting are fit for deletion. I am sorry I did not understand Thomas’ comment.
As a math Ph.D. who teaches math and physics in high school, I am curious about the proposed Scarsdale curriculum, and in what way it is supposed to be superior to the AP curriculum. I agree with various previous comments that the string theory part is unlikely to be more than a tiny part of the course, and was hyped in the article by someone who thought that it was a major selling point.
Rob, I wonder exactly why you think the AP (Physics) curriculum is ridiculous. I’m not wedded to it, and I do dislike the rigidity, but I can’t say that it emphasizes simply memorizing facts…could you elaborate?
For those who don’t know, I’ll note that there are two AP Physics courses: AP Physics B is a non-calculus based course, which covers basic mech and E&M as well as a smattering of waves, fluids, and modern physics. I haven’t taught that one. AP Physics C covers less material—just Mech and E&M—but uses calculus (which is usually taken concurrently—tricky but manageable) and makes students work deeper and more involved problems.
They may be using the words “string theory” in a very general sense. They may start with something on the electromagnetic interactions and gravitation. Followed by something on the nuclear forces, then the idea of unification (which would allow them to include some basic mathematics, group theory, etc). It doesn’t have to be too bad.
Peter says: “This is not what “dissenters” think, this is what most physicists who are not string theorists think.”
Looks to me like you are trying to do a statistics of the high energy community, AFTER excluding the string theorists. Isn’t that the same thing as putting in your answer by hand? Besides, I am not willing to take your anecdotal evidence (that you know “many, many scientists” who are against string theory) at face value. A much more objective measure is the preprints that turn up on hep-th everyday. The overwhelming majority of them are string-inspired.
Also I want to emphasize that the relevant consensus here is that of the people who are competent enough to understand the problems and merits of the various ideas in high energy theory. NOT the generic scientific community. (nobody asks particle physicists about plasma physics, if you notice). And within the high energy community, it would be ridiculous to claim that string theory is not a major theme, because your blog itself is afterall a dissent against this consensus.
So again: if at all the kids are to hear *anything* about the frontiers of fundamental physics, it is reasonable that they hear about string theory. It is one thing to emphasize that the theory is tentative, quite another to turn it into a war against tentative ideas. It is precisely the ideas that are not fully understood that trigger the imaginations of both a seasoned researcher and a beginning student. People who are trying to make the curriculum “safe” are not getting what drives human curiosity. Me, I see nothing wrong with a little mention of string theory in school, as long as it is not hyped up drivel.
somebody,
Despite what string theorists like to think, there are many physicists and other scientists competent to evaluate whether the idea of string theory unification has had any success or not. Even if one is not an expert in the technicalities of a subject, one can listen to the case made by its proponents, and see what evidence they put forward. Here, it is inarguable that 25 years of intense effort has led to absolutely zero in terms of predicting anything or explaining anything about beyond the SM particle physics. Any competent scientist can read books like Susskind’s “Cosmic Landscape”, and see that the subject is at a dead end.
This is the problem with promoting teaching string theory as the “frontier” of the subject. It may be be interesting, but it’s not a good use of high school student’s small amount of time studying science to be explaining a complicated speculative picture that doesn’t work. The problem isn’t just with the fact that if people do this, they will hype the subject, the problem is with the whole idea.
I gave you an objective way to measure the opinions of the hep-th (NOT string) community: papers everyday on the arXiv hep-th. You say that people n other fields of physics who get the story of string theory from popular science books should also count. I simply disagree. This is not how it is ever done in any other field, so why should high energy theory be a popularity contest? Expertise counts!
Once again: My claim is that if we plan to teach high school students something about the cutting edge of fundamental physics, the scientific consensus that string theory is relevant should not be ignored. You keep repeating your opinions as though they were facts, but that still does not make them the opinions of the community.
Somebody,
The consensus of the scientific community is that ‘string theory’ is just speculation until there is some experimental evidence for even a small part of it.
Here by ‘scientific community’ I mean something broader than ‘high energy particle theorists’, but not much broader than ‘professional physicists’ (surprisingly to some the preceding two categories are not the same).
There are thousands of scientific ideas that ought to be presented to high school students before they are exposed to something like string theory.
somebody,
If you talk to your non-string theorist physicist colleagues, I think you’ll find that their sources of information about string theory range from popular books to colloquium talks by string theorists to having taken a course on the subject to having worked on it and stopped. I also think you’ll find a great deal of resentment about the way string theorists are dealing with their own failures by telling their colleagues that they are just too ignorant to appreciate what they are doing.
The bottom line here is that, after 25 years of intense work, there is zero evidence for string theory unification. You don’t have to be an expert to understand that this is not a promising situation, or that this is not something you want to present to high school students, unless you’re trying to teach them about the sociology of science, not science itself.
Now I’m tempted to start a blog dedicated to complaining about how, after 20-odd years of work, there has been no definitive success in building a theory of high-Tc superconductors. What are these condensed matter theorists wasting their time on, anyway? They better not try to tell me I don’t have the expertise to judge them.
anon: One obvious difference here is that there is experimental proof high-tc superconductors actually exist.
anon,
I haven’t noticed condensed matter theorists with unsuccessful high-Tc superconductivity models trying to get them taught in high school…
This from Zwiebach’s “A First Course in String Theory”:
“When we think about teaching string theory at the undergraduate level the main question is “Can the material really be explained at this level?” …the basics of string theory can be well understood with the limited tools acquired in the first two or three years of an undergraduate education.
…A First Course in String Theory should be accessible to to anyone who has been exposed to special relativity, basic quantum mechanics, electromagnetism and introductory statistical physics.
While the mathematics for string theory is discussed at
http://www.superstringtheory.com/math/index.html
This includes real analysis, complex analysis, group theory, differential geometry, Lie groups, characteristic classes, homotopy, , fiber bundles and more.
I seriously doubt there is any high school student with this background in physics and math.
I remember, 20 years ago, reading high-level overflight articles about string theory in “Science & Vie”. Meanwhile: learning the basics of calculus, complex and real analysis in advanced math courses. Fighting english and french grammar. Studying the causes of WW1 (yes, really). Reading mandatory novels for literature classes. Cramming (really badly taught) economics 101 for the ‘bac. … And our physics teacher frantically trying to give us a 1-hour overview of things not seen in the classroom before students left for exams and the wider world beyond — the ones seen being mechanics, heat, LCR electronic circuits (no memristor yet), simple Newtonian mechanics and the Compton effect – with the mathematics just starting to be useful. Ah, youth.
String Theory? Under these circumstances? Shurely not.
I believe you could teach some real high-energy physics in high school if you cut into the subject the right way. In college (about thirty years ago) a visiting professor named Irving Reichert taught our “Physics for Poets” class out of his manuscript for an innovative introductory textbook. The main idea was to teach the correct physics at the particle level first by focusing on the basic known conservation laws (momentum, strangeness, charge, etc.). Special relativity was assumed from the outset. Typical problems were about particle collisions and what could go in or out from different interactions, how to interpret bubble chamber data, etc. (This was all handy when we took a field trip to Brookhaven–we had some idea what all that gear was for.) Lots of high-school algebra was involved, but nothing more advanced.
One of his pedagogical points was that he could do quite a lot without having to use any calculus (even though I was taking multivariable calculus at the time). Another was that students who had been excited by media reports of cutting-edge discoveries in high-energy physics were turned off by intro courses’ usual diet of frictionless blocks sliding down planes and so on. A third was that the Newtonian stuff was an approximation so why start with that? (I should point out that he was not a high-energy guy himself–I think he told us he worked on the magnetic behavior of electrons in helium and could do his experiments on a tabletop.)
I’ve never been able to find his textbook, so perhaps it wasn’t published. He was a heck of a teacher, though, and I appreciated his innovative spirit. In any case, he showed that you could teach high-energy topics in a more-than-superficial manner without advanced math.
David Metzler alludes to this above (and as an AP teacher he clearly knows), but I thought I would clarify since some people seem to have the wrong concept of what AP Physics C (the calculus-based one) is: There is no modern physics taught at all, certainly no quantum, no relativity, not even optics or stat mech. There’s no time. It could be the students’ first physics class, and half is devoted to mechanics and half to E&M. It is supposed to be the equivalent of a rigorous freshman college series, not some overview of ‘exciting topics’.
While there may be room at some high schools for more advanced physics, it seems silly to replace a foundation class.
Hmmm…yes, well, call me old fashioned, but wouldn’t it be better to ditch the AP in favor of actual college undergraduate level physics? You know, the good old Lagrangian and Hamiltonian formulation of mechanics, thermodynamics, classical field theory, electromagnetism…the good stuff!
There really is no need to be teaching string theory at all (I think some of the comments above more or less overlooked that point of view — ditching the AP is not bad, but replacing it with string theory should be seen even by string theorists as nonsensical; why not teach them quantum physics before classical?).
Thanks to J.F. Moore for the expansion/clarification of my comment. I’m a bit confused by AngryPhysicist’s comment; AP physics is intended to be (and, if taught well, is) equivalent to standard college freshman physics, not the more advanced treatment he alludes to, usually taken in the junior year. That would be quite a tall order for a high school class.
One thing that’s very important to remember in discussing freshman/AP physics is that most people taking such a class are not going to be physics majors, much less physicists. The majority will be engineers, or other types of scientist. Hence there are two strong motivations for spending a lot of time on blocks and pulleys (which a previous commenter seemed to suggest was boring). First, even for future physicists, you have to start with familiar examples to build intuition about Newtonian mechanics, before you go to Hamilton/Lagrange, much less QM. Second, I really want the guy building the bridges to understand that stuff!
The AP subjects don’t handle things such as Lagrangian or Hamiltonian mechanics, much less classical field theory! Consider discussing symmetries of a classical system using diffeomorphisms much less! So why would you skip this to go to string theory? Especially since everyone acknowledges these subjects are fundamental to more advanced physics.
That’s why I remarked “Why not teach them quantum mechanics before classical mechanics?” It makes no sense to teach them string theory without having them know the basics of quantization of gauge systems and general relativity, which requires knowledge of quantum theory and classical field theory, which requires knowledge of the Lagrangian and Hamiltonian formulations of mechanics. To just skip all this is nonsense.
So is it good to abandon the AP? Well, I think the entire public education system in the US needs to be completely redone…so it’s a moderate step forward. Is it sensible to replace AP physics with lectures on string theory? Not in the least.
(By the by, the “intention” is to have the AP be “equivalent” to college work just like how eating out of a dumpster is “equivalent” to being inoculated.)
“The AP subjects don’t handle things such as Lagrangian or Hamiltonian mechanics, much less classical field theory! Consider discussing symmetries of a classical system using diffeomorphisms much less! So why would you skip this to go to string theory?”
I think the purpose of teaching something like this is not to leave the students powerful enough to start computing, say, scattering amplitudes. It is merely to let them know that physics is not a finished business. You don’t have to be able to talk string theory, in order to talk *about* string theory. The value is more inspirational, in order to emphasize that there are plenty of questions (that are not merely details), which we still don’t understand. As a kid, I distinctly remember being fascinated by the idea that general relativity was not consistent with quantum mechanics and that resolving this puzzle might be at the heart of resolving the puzzles behind big bang and black holes. I think this is the kind of context where one could drop a line about string theory in a high-school curriculum.
Back to Peter and the blind-leading-the-blind debate:
THE overwhelmingly major candidate for the cutting edge of fundamental theory is string theory, despite repeated claims by Peter otherwise. You cannot simultaenously make the claim that departements all over are being hijacked by string theory, while at the same time claim that string theory is not popular. It is simply ridiculous, no matter how many of your devoted followers here agree with you. Facts are simply not decided on the basis of democracy. About whose consensus is relevant: I am old-fashioned with these things and have to stick with my claim – that high energy physicists are better qualified to judge high energy physics, than people who have learnt about it from popular books and expositions. Shrug!
Somebody, Anon.,
You are correct that facts are not determined by democracy — but that also means they are not determined by which research groups have the most members, nor by how many arxiv papers there are. They are determined by nature.
String theory, despite its mathematical successes, and the extraordinary cleverness its researchers have shown at working on its internal problems, has very little to show about physics beyond the speculative.
There has also ben a considerable lack, until recently, of frank self-criticism within string theory. There are plenty of statements from prominent proponents of string theory which reflect very poor judgement in this regard. So the credibility of judgments by the in group has been seriously cast in doubt by their own actions.
If you want to defend string theory at this point, it would be best to explain exactly what you are defending, and what previous claims you think were excessive. Remember, most of us have in mind overblown prior claims, statements by prominent string theorists to the effect that nothing but string theory can possibly be right (and so work on other approaches ought to die out), that wherever string theory leads (e.g., the landscape) must be right, etc. — which many of us feel are indefensible positions.
Meanwhile India and Pakistan and China and Iran are teaching according to a “Plutonium Curriculum.” As someone planning on a second doctoral program, namely a Doctorate in Educational Leadership, I find the American position indefensible, in both scholarly and Pentagon senses of the word. India had a multiverse theory, in Sanskrit, a millennium ago. Now, instead, they have more computer programmers than does Silicon Valley, and an Indian flag on the Moon (with the Chandrayyan-1). China had the theory that there were innumerable planets in the universe, then moved on — and had their first “space-walk” this Fall. We do not have the luxury to gaze into our stringy navels. There is a real world, with real competition.
“and the extraordinary cleverness its researchers have shown at working on its internal problems”
You take out Witten, Vafa, and a few others, and their cleverness probably goes below the average in sciences!
Pawl says: “You are correct that facts are not determined by democracy — but that also means they are not determined by which research groups have the most members, nor by how many arxiv papers there are. They are determined by nature.”
I am with you till here.
Pawl continues: “String theory… has very little to show about physics beyond the speculative. etc. etc.”
Now you see, this is no nature’s truth, this is merely your opinion, presented as a fact. And therein lies the rub. When we want to make a policy decision, like what to teach students etc., the closest thing we have to nature’s facts are the collective opinions of the relevant group of specialists, not yours or my oipinion. ArXiv etc. are good objective measures of this collective opinion. Replacing that with a more coarse (unspecialized) form of democracy, is what I am against.
About your other comments: Since you have made an effort to be reasonable, I will return the favour and respond to them as reasonably as I can. I think these are precisely the kind of questions asked by people who are not directly involved with the premises and challenges of high energy theory, so it might be useful to answer them. But these are off-topic (in as far as any discussion of the string controversy can be off-topic on this blog), so I will post them as a separate message.
While all of us are painfully aware of the severe shortcomings of string theory on the experimental verification front, there is simply no denying its incredible attractiveness to intelligent young people, who are too idealistic to study anything that would prepare them for a job and want nothing other than to learn the most fundamental physics. Every teenager/20 something believes that maybe he/she will crack the problem.
Over and over and over again, young people keep on approaching me saying “I want to learn string theory. Where should I start?”
Under the circumstances, all I can do is to make them aware of its problems, aware of the job prospects, then tell them about the 5 or 6 basic textbooks on string theory and hope that at least they will learn some conformal field theory and/or get a global view of modern mathematical physics.
We can use string theory as an excuse to introduce an incredibly large amount of very good mathematics and mathematical physics.
Dear Pawl, you say that string theory is speculative. But what exactly do you mean by “speculative”? In my opinion, string theory is probably THE most conservative extension of well-understood physics. It contains only the most well-accepted ingredients of physics (like say Feynman diagrams), with a single extra piece: that particles are extended strings. Everything else follows automatically (if one is infinitely smart).
I think what you might possibly mean by “speculative” is not so much that the theory is full of ad-hoc constructions, but that some of the *solutions* of the theory could give rise to a lot of exotic physics, like branes and extra dimensions and what not. (Incidentally, notice how this question is subtle and requires some training to even pose correctly.). But having exotic solutions is not an unknown situation in physics. General relativity has them too. This is hardly a reason to discard it without further thought.
The way I look at it, the experimental difficulties with string theory are basically a problem that ANY theory of the Planck scale will have to face. The real question, which gets usually drowned in the caricatured attacks, is whether we know enough to extrapolate to Planck scale from what we know at low energies. I personally think it is NOT ad hoc speculation to extrapolate, but again, this is precisely the question that I think requires some expertise to form a fair judgement call.
Now, about self-criticism in string theory. Here I think you are confusing two closely related, but fundamentally different phenomena. I think you are conflating the public hype of string theory in the media with the workings within the community. Again, the hep community is a LOT more stringent than what one might think from reading about string theory in the popular media. I cannot think of even one idea that got popular, which was accepted without sufficient scrutiny. Every SINGLE valid criticism of string theory (and its resolution) has come from *within* the community, not from outside, as many people would like you to believe. In particular, I think Smolin and Woit did a good job of counterbalancing the hype, but scientifically, there were absolutely no surprises from either of them. There are even main-stream figures who are vocal against some of the widely held notions within the community. Like Tom Banks. They are not booed out of court, but that is because they have more than superficial things to say.
About previous excess claims by string theorists. This is again a hype issue and a phenomenon you can only see in the public media. Within the community, the amount of attention an idea receives has always been roughly correlated with the intrinsic value of the idea, and has never been dependent on the hype. Most of what goes as tall claims in the media, did not get much traction within the community. In fact I cannot think of even one example for that happening. For instance landscape statistics gets an inordinate amount of attention in the media, but most people within the community are not really into it, because they would like to have a better way to pose the problem. Landscape is something we still don’t understand well in string theory, but usually not for the reasons that it gets bashed for, in superficial debates.
PS: By the way, Peter, I have to say that I respect your integrity when posting these comments. My previous message actually got stuck in the wordpress filter, and I was worried that maybe you censored it, but happily, you liberated it. Despite the fact that I disagree very much with you on much of your views on string theory (while agreeing very strongly with you when you fight the string hype), it is refreshing to know that you are not going down the easy path of censoring stuff – which is a trap very easy to fall into. Of course, this does not mean that I am going to go easy on you in the future, ha! Cheers and respect!
I’m a mathematician who took AP “Physics C” decades ago.
For those not in the USA, “AP physics” means a calculus-based one year class in Newtonian mechanics (no Lagrangians or Hamiltonians) and basic electromagnetism. The standard textbook was, and as far as I know still is, Resnick & Halliday.
The real problem with both the physics AP and whatever Scarsdale etc might replace it with, is that (1) the mathematical prerequisites are acquired concurrently rather than in the preceding year, and (2) the nominal prerequisite in physics (a qualitative, non-calculus one year class in physics standard in US high schools that offer AP Physics) is a joke and completely superfluous for the AP material. What works much better is to eliminate the year of joke physics entirely and replace it with a full year of calculus (in AP terms, “Calculus BC”).
Dear Somebody,
I very much appreciate your continuing this dialog thoughtfully. You raise quite a few points, and I will do my best to respond relatively briefly.
It’s curious that you take issue with the statement that string theory has little to show about physics beyond the speculative, to the point you doubt whether we mean the same thing by “speculative.” As I noted before, string theory does have mathematical successes, and it has internal successes — remarkable cohesions, etc. But it hasn’t had any predictive successes, which is how we usually judge physics.
So I would say that all of string theory’s contributions to physics are speculative — inspired guesses, which may or may not turn out to be right. (And the track record in science is of course that far more speculations — even beautiful ones — turn out to be wrong than turn out to be right.)
Your comments lead me to think you don’t really think of string theory as speculative in this sense. (And that would explain much of the rest of what you have written.) So I am going to speak to that. I don’t want to trash string theory as an approach to quantum gravity, because I do think it is a reasonable one to investigate. What I am arguing for is viewing its prospects reasonably.
To begin with, it is very rare in physics that fundamental theory can make much progress without experimental input. We simply are not clever enough to anticipate what nature will do most of the time. Moreover, it is very rare to be able to successfully guess what will go on many orders of magnitude from what has been experimentally investigated. There are simply too many ways nature can surprise us in the intervening regimes. So the fairest evaluation of any theory of Planck-scale quantum gravity would be considerable skepticism.
As to string theory particularly, again, reasonable people can work on it, but there are also good reasons for thinking that it may well be entirely misdirected. As you say, it is rather conservative in some respects. Its basic physical idea — moving from point to string (or brane) interactions — seems hardly to be the sort of profound insight that one would expect to be the lynch-pin of a successful theory of quantum gravity. (Compare, for instance, the sorts of wrenching new physical insights which went into creating quantum theory and relativity.) Too, its premise is that one can quantize gravity without centrally dealing with interpretational issues in quantum theory. That might be true, but it could also very easily be wrong. And the reliance on supersymmetry and extra dimensions — well, that just might be wrong, too.
The point here is not to discard string theory (although, again, the only fair assessment of any theory of quantum gravity at this point is that it is likely to be wrong). The point is that other approaches should be investigated. This has sometimes been acknowledged by string-theorists, but the demographics of the subject (who is hired, what the standards of review are) tell a different story. Very nearly all of the quantum-gravity eggs have been put in one basket, and that is simply the wrong strategy for the community to adopt. And they’ve been put in that basket because of aggressive actions from the top of the string-theory community. The effect may well be to have made the world safe for string theory, but to have retarded the prospects for getting the right quantum gravity theory.
The general mode of proceeding in string theory has been copied from particle physics, for obvious historical reasons. That is, write down Lagrangians, do path integrals, don’t worry too much about foundational questions. That worked in particle physics, partly because it all turned out to be quantum field theory, but more because there was a continual confrontation with experiment which weeded out a lot of erroneous theories. (But even there, the weeding was slow, and at many times progress was very hard.) But it’s not at all clear that that is the right way to proceed in trying to quantize gravity.
I’ve spent some time trying to give a down-to-earth view of string theory’s prospects, because of your hesitation in accepting that it was speculative. I want to quickly address another point you make.
I do take your point that some of the hype from the string-theory community is for external consumption (or is simply self-serving), and I know string theorists who smile or cringe when they hear it. On the other hand, there are cases of internal hype (for example, the claims of “obvious finiteness,” an argument which was made vociferously as one way of justifying the large amount of resources going to string theory).
But my main concern is not so much the minutiae of the arguments as the big picture. String theorists seem not to have taken seriously (by which I mean, as far as allocating funding, hiring, etc.) that it would be more important to try to encourage a diversity of work than to concentrate work on one theory.
When I was taking high school physics we studied topics like the inclined plane, the pulley, charged rods and the Bohr atom.
this has probably been said, but the web tutorial mentioned above (superstringtheory) and general articles by Witten in Physics Today seem to me as a nonphysicist (who took physics to do math biology, which uses alot of the formalisms, from cond-mat to wick rotation) seem actually to me to be pretty good introductions which could be used as a ‘special topic’ day (or a few) to generate interest and motivation to learn the required math ,which is pretty universal for any field, at least at the intro level. I was amazed to see string theory was based on basic ideas like the classical wave equation, and duality in e and m. You can even get your lagrangian and action principle, etc.
I think maybe wikipedia may be just as good for many things, maybe even better than MIT open courses.
Dear Pawl, I just saw your message but thought I will reply anyway since I have some time. Your arguments are really against high energy theory altogether (as you probably realize), and not specifically against string theory. You haven’t really got the distinction I was trying to make between speculative constructions which are often quite arbitrary, and a solid, robust theory which builds from the fundamental ideas of physics and merely cranks the formalism (in some sense) and churns out extraordinary insights (like gauge-gravity duality).
This distinction is what makes string theory so extremely appealing to so many. And a lot of the critics merely brush it off as “speculation” (while often making some concessional words about the mathematics of string theory), and equate it in value to a lot of other cock-and-bull stories that theorists come up with. This incomprehending nature of the critics is the reason why it is a little hard to take them seriously.
The sociological ways in which theory and experiment interact need not always be the same. At least a few times in history, our problem was not so much that we took our theories too seriously, but that we didn’t take them seriously enough. Quantum field theory was not trusted for a long time because of the infinities (from 40s to 70’s almost) unttil the standard model was unravelled. Big bang was considered so speculative that nobody even cared enough to look for its signature.
My point is that it is merely your personal claim when you say that experiments and theory have to interact in a certain sequence. Of course, experiments are necessary in physics. But the challenges facing science will change qualitatively as generations come and go. It is quite likely that in the future, experiments are going to be hard and theorists will have to work very hard (and perhaps long ) in order to relate theory and experiment. The light is going to be only at the end of the tunnel. This is just the way things are going to be. Does that mean that high energy theory has to be shut down? If there came a stage where it was provably impossible to connect theory and experiment, I would consider that possibility. But otherwise, I would vote for pushing forward, because I think theory is our last line of attack against the frontiers of our ignorance about the universe. Shutting it down will be the end of curriosity. If you think objectively about why exactly society sponsors things like mathematics, particle physics etc., I think you will find that it is not such a horrible thing to do, to support research in theoretical high energy physics of this kind.
It is in such a context that one has to really weigh the balance of judgement against a theoretical idea. How robust is string theory is the real question. Not cheap caricatures, like “no experiment, so string theory is useless”. These are just another form of veiled hate against theoretical physics itself, the not so uncommon hate against the top of the food chain, if you know what I mean. It was there back when theory was still dealing with experimentally accessible things, but then the criticism took a different form. Then it was “no practical use”, now it is “no experiment”.
In the above two paragraphs, I was taking on your experiment-above-all-else argument: the claim that string theory is useless because there are no experiments. (This is actually not even fully true considering the recent RHIC etc. experiments.) The real problem with these shallow criticisms is that they *totally* fail to see that a good theory teaches us deep insights and understanding about the things that we already knew, but thought were distinct. String theory has taught us that gravity and gauge theory can be understood in terms of each other (notice that between the two they exhaust all of dynamics.) Then thereare things like black holes, etc. where string theory has truly found ways to get past previous challenges. Notice that none of these things have anything to do with the fancy math aspect. If you believe that this sort of understanding is without value, then you are correct that string theory is not for you.
Dear Somebody,
Thanks for responding. However, I don’t really think you’ve understood my points. I won’t reiterate them, but I will try to sketch what seems to be preventing commuication.
Rather than take up what I have said, you are entirely misrepresenting me (saying I am against high-energy physics altogether) and shifting the discussion to a straw man (people who “brush off string theory as ‘speculation'”). You spend your post discussing what “the critics” of string theory say without taking up with what I say.
It is also disturbing that when I raise some criticisms of string theory, you amplify this into a question of whether theoretical physics is worthwhile or not.
Please reread what I have written.