An assortment of interesting things I’ve run across recently:

There’s something called Multiversal Journeys that seems to organize lecture series on theoretical physics, with a special interest in the multiverse (at least to the extent of using it as an inspiration for the organization’s name).

UC Davis particle physicist John Terning has a weblog. Also a new graduate-level text book on supersymmetric field theories, entitled Modern Supersymmetry: Dynamics and Duality, soon to be published by Oxford.

Ever since 2001, the physicists in Paris have been running a Seminaire Poincare, modeled after the mathematicians famous Seminaire Bourbaki. The latest Seminaire Poincare was on the topic of Quantum Decoherence, and texts from the older meetings are available.

Harvard philosopher Hilary Putnam has an updated version of his 1965 article “A Philosopher Looks at Quantum Mechanics” in the latest issue of the British Journal for the Philosophy of Science. It is entitled A Philosopher Looks at Quantum Mechanics (Again). Part of my misspent youth involved taking several philosophy courses as an undergraduate at Harvard, including ones from Quine and Putnam.

In November, Joe Lykken gave a particle physics seminar at Princeton entitled Is particle physics ready for the LHC? His talk explains some of the challenges particle physics will face at the LHC. The next-to-last slide is a none too subtle dig at the lack of any particle phenomenology going on at my alma mater. It is entitled “is Princeton ready for the LHC?”, and lists the titles of the particle theory seminars going on at Princeton during the period before his talk.

The International Committe for Future Accelerators (ICFA) has a new web-site.

The Tevatron has recently achieved new luminosity records, both for peak luminosity and integrated luminosity over a week. You can follow the status of the Tevatron here.

A beautiful new paper by Greg Landweber and Megumi Harada has just appeared. It is entitled A comparison of abelian and non-abelian symplectic quotients and uses equivariant K-theory methods to get the relation between the K-theories of the symplectic quotients M//G and M//T, here T is the maximal torus of a compact Lie group G.

Update: One more. Slate today is advertising Meaning of Life TV, where various people, including some physicists, do things like promote the idea that the anthropic principle shows religion has a lot to do with science. This site has been around for a while, but just now has affiliated with Slate. Looking at it I thought “funny, this is the only thing like this trying to inject religion into science that doesn’t seem to be a Templeton Foundation project.” Then I saw the About Us link.

This entry was posted in Uncategorized. Bookmark the permalink.

### 23 Responses to Yet More Links

1. Alan Reifman says:

Also to consider for one’s reading list, there’s a new book on the standard model. It’s entitled “The Theory of Almost Everything,” written by Robert Oerter, a professor at George Mason University. Further information on the book can be accessed by clicking on Oerter’s webpage:

(Info on the book is underneath where he lists his course pages.)

2. QWERTY says:

THAT IS A RATHER NICE PAPER AT THE END. I FIND GIT VERY DIFFICULT BECAUSE THE SURJECTIVITY ARGUMENTS ARE A LITTLE BIT SUBTLE.

APOLOGIES FOR GOING VERY SLIGHTLY OFFTOPIC, I AM PRONE TO DO THIS OCCASIONALLY AND HOPE YOU WILL NOT THINK LESS OF ME FOR IT.

I HEREBY DECLATE THAT I, QWERTY, SUPPORT ISRAEL GELFAND FOR THE ABEL PRIZE 2006. I WAS APPALED AND DISGUSTED WHEN PETER LAX WON IT LAST YEAR. I THINK GELFAND DESERVES IT BECAUSE HE IS VERY CLEVER.

PS I HAVE NAMED MY PET HAMPSTER GELFAND IN HIS HONOR.

PPS I THINK YOU SHOULD TALK MORE ABOUT MATHEMATICS AND LESS ABOUT PHYSICS

3. MathPhys says:

Peter,
Why do you consider your time attending Putnam’s and Quine’s classes misspent? I have my own ideas about that, but I wish to hear yours.

4. woit says:

I took a class from Quine on mathematical logic, which mostly was him reading from ancient lecture notes (the notes were on cards from what I remember). I don’t remember as much about Putnam’s class, I think I was just auditing it.

When I started college I was quite seriously interested in philosophy, especially philosophy of science and mathematics. While, outside of his class, I greatly enjoyed reading some of Quine (and to a lesser extent Putnam), and found his view of how physics fits into philosophy quite congenial, in the end it seemed a lot more interesting to deeply study math and physics themselves than to study “philosophy of” math or physics. The deepest questions about these subjects seem to me not the ones that are addressed by philosophers, but ones that our lack of sufficient knowledge of these subjects still leaves us unable to answer.

For example, the current debates over whether the multiverse is science, falsifiability, etc. aren’t truly deep problems in these subjects. They are coming up because people are refusing to honestly go after the real problems. Philosophers may be useful in getting people to think clearly and honestly, and they may contribute to these issues now. But they can’t help much in creating the kind of new math and new physics needed to make progress on fundamental problems.

5. secret milkshake says:

Feynman: “Physicists are explorers, philosophers are tourists.”

6. Sakura-chan says:

““A Philosopher Looks at Quantum Mechanics” in the latest issue of the British Journal for the Philosophy of Science. It is entitled A Philosopher Looks at Quantum Mechanics (Again).”

Hmmmm, I think there’s like five people in the world who have subscribed to The British Journal for the Philosophy of Science Online, and I’m sure not one of them. =D Is it worth my \$?

7. mgimo says:

While agreeing essentially with Woit, I’d say that mathematical logic provides an interesting blend of philosophical and mathematical questions which can be studied from a mathematical point of view. As tools of mathematical logic develop, one hopes that they enable to answer philosophical questions by meaningful mathematical theorems. For example, now there are meangful (mathematical) tools to tackle the question why “why we study what we study”…

8. logopetria says:

“Philosophers may be useful in getting people to think clearly and honestly, and they may contribute to these issues now. But they can’t help much in creating the kind of new math and new physics needed to make progress on fundamental problems.”

In most periods of science, this is probably true. When we have lots of data, and multiple theories competing to explain it, with new theories and variations being spun off and explored all the time, there’s probably little that a philosopher can add to the party. But high-energy physics generally isn’t in a period like that at the moment. Not least in quantum gravity, new experimental data is relatively sparse, and progress is mostly in pure theory.

That (arguably) means that new developments will come from two sources: new mathematical techniques and ideas, and new ways of thinking about and understanding our old theories. There’s a decent chance, then, that some of the useful new ideas that will help move the field forward might come out of philosophy of physics, rather than physics alone.

Of course, philosophers can only be helpful in these areas when they have relevant knowledge of the subject in question. Fortunately, there are quite a few researchers in philosophy departments who have a very solid background in physics as well. A good cross-section of this work is given in the book “Physics Meets Philosophy at the Planck Scale” edited by Craig Callender and Nick Huggett (many articles from which can be found online: click on “logopetria” above).

9. woit says:

Sakura-chan,

I mentioned the Putnam article because I think it is historically interesting: Putnam is one of the more well-known philosophers in the US and his 1965 article was often-cited as influential. Like the old one, the new article is very clearly written, and it also has some interesting asides about Einstein’s views and those of an unidentified “world-famous physicist” (I’m guessing Feynman, may be wrong). But I don’t think the article is especially good or original in terms of getting at the real problems of the interpretation of quantum mechanics (e.g. decoherence is not even mentioned).

10. Juan R. says:

secret milkshake said,

Feynman: “Physicists are explorers, philosophers are tourists.”

From what perspective?

Well, Feynman was a physicist, one great but only was that. Feynman philosophical insight was very superfitial. For instance his “Character of physical law” and similar works are often cited in philosophical courses as an example of superfitial approach to serious epistemological and ontological stuff.

Therefore,

Physicists are explorers, philosophers are tourists in the physical land

AND

Philosophers are explorers, physicists are tourists in the philosophical land

“A Philosopher Looks at Quantum Mechanics” again 🙂 has no real interest for science. In fact, one can easily see many ideas about scientific hot topics launched by philosophers are completely wrong. For instance, one can read all nonsense published by philosophers about quantum measurement, irreversibility, absence of time in last decades.

I agree with Gell-Mann that philosophers would do just philosophy and leave physics (and probably epistemology) for physicists…

Juan R.

Center for CANONICAL |SCIENCE)

11. Chris Oakley says:

From the Slate web site:

John Polkinghorne: “The laws of nature were just exactly finely tuned to allow [life] to happen. It couldn’t happen in just any old world. That’s a very striking fact about the world …”

Statistical inferences based on a sample of one.
Wear a “D” cap and stand in the corner.

12. Attila Smith says:

Dear Qwerty,
Although some party-spoilers might find your opinions controversial,
at least they are not smug and boringly PC , like ***’s or ****’s or above all *****’ s.
Greetings to Gelfand (your hamster, needless to say).
Abelian greetings,
Attila.

13. fooltomery says:

The Templeton Foundation never stops trying to buy a stairway to heaven…

Well, I can’t resist a moderate defence of philosophers.

It is true that some philosophers of science have done little more than add noise to the debates, but some others have also contributed very usefully. It was philosophers who were the primary sceptics about the Copenhagen interpretation through the 40s and 50s. It was philosophers who were the main enthusiasts for the quantum logic approach of Birkoff and von N. and it was they who were the primary sceptics when it looked like it wouldn’t work. And now that physicists are rushing as one (the herd instinct seems quite well developed!) to think of decoherence as the solution to the measurement problem it is philosophers who are trying to point out to them that it just won’t work.

Physicists are often condescending about philosophers but when they attempt to to do philosophy themselves (because they think they can do it with their eyes closed, with no training at all) it is often embarassingly sophomoric. Witness Susskind, Weinberg, etc.

When philosophy of science is done well it is done by people who know the maths, know the physics, and look at the theorems as external scrutineers. They are trying to answer the question ”Yes, but what does it all mean?” in a more sceptical and frank way than physicits often manage unaided. Philosophy is (as some politician once said) there to keep the bastards honest. And in quantum mechanics it has been remarkably effective, particularly over the last thirty years.

I wouldn’t expect much from Quine or Putnam. Putnam I think has never kept up with the literature. He listens to his friends, puts together his ideas from conversations with the *people who matter*. His ideas veer all over the map because he thinks quickly but no longer particularly well. Quine had the same arrogant attitude—but gave the impression of having even less contact with the outside world.

I should add that I think Peter W. is an exception here: his philosophical instincts seem judicious and right, to this writer anyway. Maybe those few courses he audited had a salutary effect. 🙂

Philosophers, it is true, have largely ignored string theory. But that also is to their credit. I think they can tell vapourware when they see it.

15. j says:

As a student looking to grad school, the contentious/complementary relationship between modern science and philosophy is both fascinating and troublesome. To pursue a more humanisitic approach to physical science or a more rigorous bend in philosophy? I’m pleased to see the topic arising here (if only tangentially) and that Prof. Woit faced similar considerations as an undergrad.

Out of curiousity, can anyone cite examples of philosophers [of science/math] that appear to “get it”? Is anyone familiar with the work being done by Hans Halvorson at Princeton?

Yes, I’m familiar with Halvorsen’s stuff. And he’s good. Very good. So also is Jeff Bub at Maryland. N.P. Landsman is a very philosophically astute mathematical physicist in Holland. Michael Dickson of Sth Carolina is good. Guido Bacciagaluppi of Paris is good (they seem to have quite a few good people in Paris—go figure?) John Earman of Pittsburgh is also good—and interested in quantum field theory.

But I don’t agree that there is a ”contentious/complementary relationship between modern science and philosophy”—mostly the relationship (at least from the philosophers’ side) is good. Philosophers who b*tch about science are an ignored minority, mostly social constructivists of one kind or another.

17. j says:

Adrian, I appreciate the list of names.
I didn’t mean to imply a signficant rift between the two disciplines or any fundamental tension, but rather my recurring experience with the cliche of the specious philosopher and the myopic physicist. (The opinion(s) of Feynman and Gell-Mann cited above being superficial, if not outdated examples.)

18. Juan R. says:

Echeverría and Rábade Romeo in general theory of knowledge, Kleene in metamathematics.

Personally, i am very influenced by Prigogine (not by thecnical details of his theory); Scerri in philosophy of chemistry…

Etc.

I do not know Jeff Bub work but i do not agree with him in [http://carnap.umd.edu/philphysics/bub_research.html]. In fact, he appears to have a serious misunderstanding of basic issues of both quantum and classical mechanics.

I do not agree with some Landsman’s work, specially his ‘wavefuntions of universe’ in quantum gravity. He has not adressed the problems of WdW and ADM quantum gravity in detail.

I think history of philosophy is the history of continuous loosing of fields of aplication in favor of rival: science. In some sense, current philosophy is the study of those fields cannot be still studied in a scientific manner.

Juan R.

Center for CANONICAL |SCIENCE)

Hi j—just a little more information. Halvorson at Princeton seems to have the aim of reviving a Bohrian philosophy of QM, partly tied to the idea that QM is ”really” about information. A number of people are riding this horse at present, including Jeff Bub. Personally I’m pretty unconvinced, and I think many people share that scepticism. But Halvorson seems to be exerting a strong influence at present.

From a different direction N.P. Landsman also seems to be looking to resuscitate Bohr. I think his 100 page essay Between Classical and Quantum is one of the best surveys around at present. Look for it on arXiv for 2005 as quant-ph/0506082.

There are many other good philosophers around that I didn’t mention: Craig Callender at UCSD, van Fraasen at Princeton, harvey Brown at Oxford, David Albert at Columbia(!) and many more.

On Feynman: apparantly he had a run-in with the neo-Wittgensteinians at Cornell in the 50s and couldn’t stand philosophers ever after.

20. Juan R. says:

I do not think that N.P. Landsman seems to be looking to resuscitate Bohr in his recent quant-ph/0506082.

In fact, i think that he is ignoring the main premise of Bohr the classical is not reducible to the quantum.

Moreover his analysis of the situation is not rigorous (there are several sound technical errors in the h-limit, N-limit, decoherence, and histories sections) and he just forget the most realistic and fascinating option in his ‘review’; the third way: that both quantum and classical are two sides of a more complex nature.

Precisely this third way is taken by Martingale models, Penrose, Prigogine theory, etc.

I myself have done some recent advance in the topic. In brief, i will publish a derivation of Martingale models and Born rules from first principles. Prigogine theory for example appears like a special case of a more general model. No other model (e.g. the popular decoherence) has done similar things.

Juan R.

Center for CANONICAL |SCIENCE)

21. Levi says:

Since the title of this post is “Yet More Links”, I hope this isn’t considered off topic. There is an interesting new paper out today by Connes and Marcolli entitled “A walk in the noncommutative garden”. It’s a long survey paper consisting mostly of an exploration of examples. Some of the examples are from physics, including string theory. The final section sketches the function field approach to the Riemann Hypothesis that Peter is fond of. The link is

http://arXiv.org/abs/math/0601054

Juan

”I do not think that N.P. Landsman seems to be looking to resuscitate Bohr in his recent quant-ph/0506082.

In fact, i think that he is ignoring the main premise of Bohr the classical is not reducible to the quantum.”

In his use of Raggio’s therem on p. 20–1, he is certainly defending Bohr’s response to Einstein, and is using the idea that the classical is fundamentally different from the quantum realm (it has a commutative C^* algebra rather than a noncommutative one). However this is all much more explicit in his other 2005 article on arXiv (quant-ph/0507220) and there the resuscitation of Bohr is the central aim of the paper rather than a side issue. Again Raggio’s theorem is the primary technical result.

23. Tung says:

Hi peter, it seems that the message i post just now cannot be seen after i click the submit button