For the latest on the status of the LHC, see the July 2 talk of Steve Myers mentioned here earlier, and a July 8 talk (slides, video) that has some more recent news. The question of what to do about bad splices is still up in the air. The current plan is to make measurements at 80K during the next few weeks on the three sectors that have not been warmed up, then present options during the second week of August to the DG and the experiments. The decision to be made will be about how long to delay the start-up to fix more splices. If more splices get fixed, the machine can safely be run at higher energy. The optimistic scenario now seems to be that it will be possible to run at some energy in the range of 4-5 TeV/beam, without introducing further delays in the current draft schedule (the latest schedule has the machine ready to start circulating beams around the end of October). Gordon Watts has more detail in a recent post, including one of the relevant plots showing the energy vs splice resistance trade-off.
Two items on the multiverse front:
You can turn an egg into an omelet, but not an omelet into an egg. This is good evidence that we live in a multiverse. Any questions?
String theorist Oswaldo Zapata has posted the third part of his essay on the history of superstring theory, dealing with the question of the “beauty” of string theory. Basically he argues that it was only in 1999, after it started to become clear that string theory unification wasn’t working out, that a publicity campaign about the “beauty of string theory” got started:
During the late eighties and early nineties, and motivated by the relative success of the heterotic superstrings, string theorists were submerged in intricate and endless computations trying to recover the standard model using a ‘‘top-bottom’’ approach. At that time no one was talking publicly about a beautiful construct. In fact, the theory was in an ugly impasse and mathematical consistency was the only remote trace of beauty…
In this section we have seen that, in contrast to what is currently claimed, string theory was not always considered to be a beautiful theory. The public recognition of the beauty of the theory is recent, dating from around 1999, and it was due mainly to the convergence of two factors: a favourable context, “internal” and “external,” and an acute sense of opportunism.
From the Publisher’s Weekly review of Graham Farmelo’s life of Dirac:
In 1955, Dirac came up with a primitive version of string theory, which today is the rock star branch of physics.
The opera Hypermusic Prologue: A Projective Opera in seven Planes, libretto by Lisa Randall, had its first performance last month in Paris. It will be presented again in Barcelona in November.
FQXI seems to like to have conferences for their members at scenic volcanic locations in the mid-Atlantic. This year it’s the Azores, here’s their schedule, talks to appear here, blogging here (Sabine Hossenfelder) and here.
Strings 2009 finally got around to putting slides from most of the talks online here. The one talk that seemed to have something new wasn’t about strings, it was Arkani-Hamed’s talk on Holography in Flat Space: Algebraic Geometry and the S-matrix, based on work to appear with Cachazo, Cheung and Kaplan. It’s based on studying the structure of amplitudes in twistor space, and the talk includes many exclamation points, and the claim that “SOME POWERFUL MATHEMATICAL STRUCTURE IS AT WORK!”. More specifically:
Very natural and beautiful mathematical structure – intersection theory and Schubert Calculus – seems to lie at the heart of tree and loop gluon scattering amps!
From the slides it does appear that there’s some nice mathematics at work here, I look forward to seeing the paper.