Thermo/StatMech

Category archives for Thermo/StatMech

Bose Condensation of Coffee?

Writing up the evaporative cooling post on cold atom techniques, I used the standard analogy that people in the field use for describing the process: cooling an atomic vapor to BEC is like the cooling of a cup of coffee, where the hottest component particles manage to escape the system of interest, and what’s left…

In our last installment of the cold-atom toolbox series, we talked about why you need magnetic traps to get to really ultra-cold samples– because the light scattering involved in laser cooling limits you to a temperature that’s too high for making Bose-Einstein condensation (BEC). This time out, we’ll talk about how you actually get to…

Hey, dude? Yeah, what’s up? I’m not normally the one who initiates this, but I was wondering: When you were at DAMOP last week, did you see any really neat physics? Oh, sure, tons of stuff. It was a little thinner than some past meetings– a lot of the Usual Suspects didn’t make the trip–…

How Good Is My Starbucks Cup?

It’s been a while since I’ve done a post over-analyzing some everyday situation, because I’ve been too busy to do any silly experiments. We’re on break this week, though, so I took a little time Monday to bring excessive technology to bear on the critically important scientific question: how good is my insulated Starbucks cup?…

This past weekend, I was at Boskone, where I appeared on a few science-y panels. One of these was on the possibility of beaming power down from space: Energy From Space Beam me down some juice, Scotty? Let’s talk about the possibilities — and practicalities — of really long-distance power transmission. Tom Easton (M), Jordin…

Last week’s post talked about the general idea of negative temperature, with reference to this much-talked-about Science paper (which also comes in a free arxiv version from which the figures used here are taken). I didn’t go into the details of how they made a negative temperature gas, though, and as it’s both very clever…

The most talked-about physics paper last week was probably Negative Absolute Temperature for Motional Degrees of Freedom (that link goes to the paywalled journal; there’s also a free arxiv preprint from which the above figure is taken). It’s a catchy but easily misinterpreted title– Negative absolute temperature! Below Absolute Zero! Thermodynamics is wrong!– that obscures…

We’re in the home stretch of this term, and it has become clear that I won’t actually be using the toy model of the arrow of time I’ve talked about in the past in my timekeeping class this term. These things happen. Having spent a not-insignificant amount of time playing with the thing, though, I…

I’m fairly certain somebody has already done this, because it’s such an obvious idea. It’s a little beyond my cargo-cult VPython skills right at the moment, though (I can probably learn to do it, but not right now), and I none of the applets I Googled up seemed to be doing this, so I’m posting…

While clearing the cars of frost Thursday morning, I was reminded of a difference of opinion Kate and I have about the best approach to a cold car. I tend to start the car up, and immediately turn the defrost on full blast; she prefers to let the car warm up for a while first,…