John Brockman at his “Edge” web-site has put up an exchange between Smolin and Susskind about the “multiverse” and the anthropic principle. This includes the page and a half paper by Susskind that was rejected by the arXiv. Susskind seems quite willing to give up the idea that a physical theory should be falsifiable, so his response to Smolin’s argument that his use of the anthropic principle is not falsifiable is basically “Yeah, and so what?”.
To Smolin’s claim that non-falsifiable theories aren’t really science, Susskind answers by listing several prominent physicists (Weinberg, Polchinski, Linde, Rees), their titles, affiliations and prizes they have won. He then announces that since these prominent people agree with him and think the anthropic principle is science, Smolin should just shut up. I don’t know about other people, but one reason I went into physics was that it was supposed to be a subject where issues could be decided by rational argumentation, not appeals to authority. That doesn’t seem to be the case anymore.
“To the extent that this is supposed to be taken as “scientists have little to learn from philosophers, and philosophers have much to learn from scientists” it is simply false”
In general, I agree. But there are bad philosophers just as there are bad physicists. On this *specific* issue, namely declarations that things we cannot see [yet] are “unscientific”, too many physicists tend to quote bad philosophy. The example of quarks is canonical. I really liked Susskind’s
“Throughout my long experience as a scientist I have heard un-falsifiability hurled at so many important ideas that I am inclined to think that no idea can have great merit unless it has drawn this criticism”. I think that hits the nail on the head.
Susskind said: “Let’s not put the cart before the horse. Science is the horse that pulls the cart of philosophy.”
To the extent that this is supposed to be taken as “scientists have little to learn from philosophers, and philosophers have much to learn from scientists” it is simply false, in light of the entire history of physics. Of course it probably expresses the attitude of most of the last 2-3 generations of physicists, and I have seen a statement by Witten to the effect that he and most of his colleagues see little to interest them in recent work (of the last two centuries?) in the philosophy of science.
My point is that no one seriously interested in a problem like quantum gravity can afford to adopt the narrow perspective of a specialist, or to be complacent about questions of epistemology. John Wheeler has cautioned against any physicist adopting this attitude, although given the vastness and technical complexity of the field, and the demands of modern research as a career, it is perhaps inevitable that such attitudes will be fairly widespread.
The contrast in outlook between Smolin and Susskind on this issue is quite obvious.
I must reluctantly confess that I found Susskind surprisingly reasonable. Surely he is right when he says “Good scientific methodology is not an abstract set of rules dictated by philosophers. It is conditioned by, and determined by, the science itself and the scientists who create the science.” It is good to see somebody explicitly refuting people who drone on about how things beyond the horizon can never be seen, hence theoretical efforts to determine what is there are “not science”. What crap! On the other hand, S does fall right off the cliff when he claims “the black hole controversy has largely been resolved.” The only question here is whether Susskind really believes such blatant nonsense.
The other strange thing was that Susskind was so polite. He only starts to sound like Lubos Motl right at the end. In fact, right at the end he sounds so much like LM [“Smolin’s tendency to set himself up as an arbiter of good and bad science”] that it is now clear to which organ-grinder the monkey belongs.
Thomas,
What do you think of the CFT book by Ketov?
Lately I’ve been slowly making my way through the book “conformal invariance and critical phenomena” by Henkel.
Danny:
Unfortunately I don’t really have any good introductory references to CFT, since I picked up most of it from the original literature around 1986-1990. Conformal field theory by Di Francesco, Mathieu and Senechal is the canonical reference, but its intimidating thickness makes it more suited as a reference rather than as a tutorial.
One probably also needs some general background on phase transitions, statistical lattice models, and renormalization in that context. The review series edited by Domb and Green, and later Domb and Lebovitz (or maybe Green and Lebovitz – anyway, one of the original editors died) is a classic, but maybe out of print. A more recent textbook is Scaling and renormalization in statistical physics by Cardy. It has the advantage that its size is manageble.
JC –
Beavis and Butthead know their limitations. Uh huh huh, yeah. Shut up, Beavis!
(Seriously, there are lots of interesting *physics* questions that lofty fartknockers such as S&S might hold forth on at length.)
D R Lundsford,
How much is this different than two idiots like Beavis and Butthead arguing which rock music bands “Rule” (ie. Metallica, AC DC, etc …) and which rock bands “Suck” (ie. Billy Idol, U2, Boy George, etc …)?
Or for that matter discussions between fans of various sports teams (ie. basketball, baseball, hockey, etc …) as to which teams “Rule” and which teams “Suck”?
This seems to be very much a human thing that is independent of the field of interest or inquiry, whenever there’s disparities in opinions which are not backed (nor ruled out) by empirical data and/or the questions asked are too vague.
Thomas –
To Glashow’s credit, he threw off his rope belt and robe and re-entered the mundane world:
http://www.pbs.org/wgbh/nova/elegant/view-glashow.html
And that 1988 paper on CFT by Ginsparg you linked is mighty interesting 🙂 Do you have a list of favorite references on this topic?
“Is further experimental endeavor not only difficult and expensive but unnecessary and irrelevant? Contemplation of superstrings may evolve into an activity as remote from conventional particle physics as particle physics is from chemistry, to be conducted at schools of divinity by future equivalents of medieval theologians. For the first time since the Dark Ages, we can see how our noble search may end, with faith replacing science once again. Superstring sentiments eerily recall ‘arguments from design’ for the existence of a supreme being. Was it only in jest that a leading string theorist suggested the ‘superstring may prove as successful as God, Who has after all lasted for millenia and is still invoked in some quarters as a Theory of Nature’?”
– Paul Ginsparg and Sheldon Glashow, Physics Today, May 1986.
Some people are true visionaries!
1 word – scholasticism. They both sould like two Schoolmen going round and round about theophany or some such ridiculous arcanity.
It would be very interesting to make a close comparison of scholasticism and this pseudoscientific form of debate. One thing’s certain – physics, at least as practiced by these two, is deader than Julius Caesar.