Wednesday, November 14, 2007


I know that I got into science because it felt like the closest thing to the thrill and mystery of magic, but it was somehow more "real". But after an event I attended Monday night -- an amazing event: magic show, trash-talking puppets, real-time candy-puppet-making, card castles that hold human weight - now I'm not sure who is more in touch with reality. I found out about this event from Mark Mitton, a friend of mine who organized the evening at the National Arts Club. You can read a bit more about the event, get links to their website, and see a few photos (taken by yours truly, like the one above of Mark, Brian and two semi-willing volunteers about to stand on a card structure...) here. The one thing that you won't see anywhere (and I botched the photographs of) was Mark's string theory trick: showing how short and long strings are actually the same size, and closed strings and open strings easily transform into each other, before one's very eyes -- no-one has to teach this guy about duality [rimshot! thankyouthankyou, I'm here Wednesdays and Sundays...]

Thursday, November 08, 2007

We Are the Champions

Who said you can't do physics and rock at the same time? Check out this entry on SPIRES:
Radial Velocities in the Zodiacal Dust Cloud.
Brian May (Imperial Coll., London) . 2007.
Wikipedia fills in some of the story:
May studied astro physics at Imperial College London, graduating with a B.Sc. (Hons) degree, and then proceeded to study for a Ph.D., having written a significant amount of the doctoral thesis, and carried out a majority of the research required, May abandoned his doctoral studies to pursue his music career with Queen.
On a similar tack, but in the opposite order, I saw my old college friend Vijay Iyer play the Jazz Standard the other night with his band Tirtha (guitar, piano, tabla trio, playing jazz strongly inflected by Indian musics). He was a physics major at Yale (like me, sort of -- I graduated with a poli sci degree, but finished a lot of the major), went off to graduate school, and simultaneously started playing pro gigs all over the world, eventually leaving physics after getting his PhD to play full-time. And now he's signed to Savoy Jazz and named top "Rising Star Jazz Artist" and top "Rising Star Composer of the Year" for the second year in a row. Great show, and further proof that sometimes you can do both science and art -- but usually only one at a time.

(Thanks, Corey!)

Friday, November 02, 2007

Granular Liquids vs. RHIC

People often use the word "glass" in relation to RHIC physics (via the Color Glass Condensate), but this is a bit more literal. From the upcoming Physics News Update #845, now RHIC is being used as a "benchmark" for fluid (or even liquid) behavior, even when the fluid is made of glass beads:
GRANULAR LIQUIDS WITH ZERO SURFACE TENSION. New experiments with spherical glass beads show that liquid behavior can arise simply from rapid collisions among a sufficiently dense stream of particles. The experiment was undertaken by Xiang Cheng, Heinrich Jaeger and Sidney Nagel and their colleagues at the University of Chicago, experts on discovering novel effects with granular materials (see and If one or two beads are dropped from above on a horizontal surface, they will bounce back in the direction from which they came. If, however, many beads are dropped all at once---constituting a dense granular stream hitting a target---then something else happens: the grains deflect out laterally in the form of a very thin, symmetrical sheet or cone as if they were a liquid. Indeed, the experiments using granular matter quantitatively reproduce results obtained with streams of water. However, with beads, the *liquid* is one in the limit of vanishing surface tension. (To ensure there was no cohesiveness between the beads, which range in size between 50 microns and 2 millimeter, they were baked in a vacuum oven beforehand, evaporating any lurking moisture.) During the short interval the beads inside the stream collide with each other in front of the target, liquid-like conditions are established whose observable consequence are the thin sheets. This novel, zero-surface-tension liquid state, the experimenters believe, might be of interest to physicists at the Relativistic Heavy Ion Collider (RHIC), where heavy nuclei colliding at high energies (see form a plasma of quarks and gluons that also resembles a liquid. Intriguingly, the collision pattern produced by the completely classical, macroscopic granular liquid can match that produced by the quark-gluon plasma. (Cheng et al., Physical Review Letters, 2 November 2007)