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Low-functioning pinhead...
July 28, 2005
July 22, 2005
Cheers and Raspberries
Sean Carroll, over at Cosmic Variance has posted a non-string theorist’s “defence” of string theory. It’s a little absurd that, given all we’ve learned in the past two decades, the field needs “defending.” But Sean’s post, and the ensuing comment thread are pretty good. Filter out the inevitable crackpots, and you can read a sober, and pretty even-handed discussion of the issues, with Peter Woit asking the the tough questions, and Clifford Johnson, Wolfgang Lerche, Bob McNees, Ann Nelson, Moshe Rozali and yours truly responding.
NBB.
Atom 1.0
The Atom Specification has been finalized. And Sam Ruby has asked that people migrate away from Atom 0.3 to the final Atom 1.0. Using Niels Leenheer’s very nice guide to upgrading, it took maybe 5 minutes to upgrade my Atom feed from 0.3 to 1.0.
If you’re using the old feed, be forewarned that it will go away at some point in the not-too-distant future. Once you’ve upgraded your aggregator software to a version that supports Atom 1.0. (NetNewswire 2.0.1, for instance, already supports Atom 1.0), point you aggregator at the new feed instead. The same holds for the feeds at the String Coffee Table.
July 19, 2005
Advice to the Young
Looking back at my response to Marty Tysanner, it occurs to me that, perhaps, he deserves a more lengthy explanation of why I found the notion, that the panel discussion at String 2005 would affect his choice of what to work on, so utterly wrong-headed.
Update (8/1/2005):
On the off-chance that I’ve failed to convince Marty that he’d be better off throwing I Ching sticks, he can read Dennis Overbye’s summary of the panel discussion.July 18, 2005
Cosmic Variance
Bring out the heavy hitters.
Sean Carroll, JoAnne Hewett, Clifford Johnson, Mark Trodden and Risa Wexler have started a WordPress-based group blog called Cosmic Variance.
Since Clifford had been rather steadfast in his insistence that he would never take up blogging, I, for one, see some sort of tipping point …
And speaking about physicists, blogging, and WordPress, I learned some interesting news at Strings 2005, which I will doubtless tell y’all about anon.
July 16, 2005
Strings 2005 Wrapup
Feeling somewhat burnt out, I’ve kinda fallen down on the whole live-blogging thing. I’ll try to make partial amends here, but, generally, you’ve have to blame the organizers of Strings 2005 for scheduling so many interesting talks during the latter days of the conference.
July 14, 2005
Day 4
Beisert gave a beautiful review of progress on spin chains and integrability of both N=4 SYM and string theory in . I think perhaps we’ll spend some time this Fall, in the Geometry and String Theory Seminar at UT, reviewing this stuff.
Maldacena and Lunin gave talks about their joint work, some of which I blogged about before. I won’t repeat what I wrote previously, but there was one remark from Juan’s talk that struck me as an important insight. From the free Fermion description, one gets a rather concrete picture of “summing over nontrivial topologies” on the gravity side. This corresponds to including nontrivial topologies (disconnected dropplets) of the Fermi surface. Juan suggested that small droplets, near an otherwise regular Fermi surface — things that might be called “spacetime foam” — are really indistinguishable from gravitons. Counting them separately from the ripples on the Fermi surface, which are interpreted as gravitons, is overcounting configurations.
I’ve long been of the opinion that string theory gives zero evidence for the popular idea of spacetime foam. Juan’s remark seems to confirm that.