Tuesday, May 22, 2007

QCD with cold atoms?

Via Chad Orzel, a PhysicsWeb new story reports a recent proposal to use a rather different kind of lattice than the one usually discussed here for understanding QCD. The authors of this PRL paper propose that ultracold fermionic atoms with three possible hyperfine states trapped in an optical lattice (a periodic potential created by crossing laser beams) would behave like quarks in QCD, including forming "baryonic" states and showing the same phase transitions as QCD matter.

I don't know enough about atomic and optical physics to be able to tell whether this proposal is reasonable. If it is, it could be seen as one of the first examples of the use of an analogue quantum computer to simulate an otherwise experimentally inaccessible quantum system. However, I can see no real evidence that the atomic system would really be simulating QCD (which includes gluons and sea quarks) rather than some kind of quark model, so I remain a little sceptical regarding that claim. In any case, this proposal shows how far atomic and optical physics has come in its ability to finely control the states and interactions of atoms, so even if it isn't QCD, it's pretty cool.

Monday, May 14, 2007


Tomaso Dorigo has a great post on the difficult decisions experimentalists have to make when deciding on their triggers, and on the human behaviour that can be observed in the meetings where they discuss and make those decisions.

To someone looking into the academic world from outside, anecdotes like the one reported by Tomaso probably sound a lot like yet another example of "academic politics is so bitter because the stakes are so low," a quotation commonly misattributed to Henry Kissinger. But what needs to be kept in mind is that the stakes are in fact, extremely high: when a researcher devotes almost every waking minute to some research project, foregoing other (much better paying) career options and postponing, or even completely giving up on, such things as parenthood and home ownership, what is at stake in discussions about that project's future role in the greater structure of human knowledge and discovery is no less than that researcher's major purpose in life. And that is a huge stake for anyone, whether they are a lowly scientist (or historian or whatever) or a mighty CEO -- although the former are far more likely to face that kind of risk than the latter, who have their golden parachutes. So a certain amount of acrimony is really to be expected.

Thursday, May 03, 2007

SciFi'ish Sunshine Scene

Via Clifford Johnson, a link to a BBC report about the first commercially operating solar thermal power plant in Europe. Located in sunny Andalusia, it generates 11 MW of electrical power from sunshine alone by concentrating the light of the sun on the top of a 115 m tall tower by means of 600 heliostats, huge mirrors that track the Sun in the sky. The concentrated light is so intense that when scattered off the water vapour and dust in the air it creates the scifi-like special effect visible in the picture at the BBC link. If this kind of power plant is shown to work well commercially, the resulting increase in energy production could be a huge boost to the economy of developping countries in the subtropics, and the Gulf sheikhs will have nothing to worry about when the oil runs out -- they have plenty of sunshine in the Arabian desert after all.