DAMOP Summary

OK, last things first. The UVa campus gets an overall grade of gorgeous, allowing for the construction that was going on. (There was a very New England “you can’t get there from here” theme that pretty much mandated that any travel between buildings required a detour of some sort) The weather was great; pretty much the rest of the month in Virginia has been cool and wet, but it was sunny and warm the whole week. I had tried to stay at one of the motels within walking distance, but they were all full when I called, so I ended up at the not-so-super-8 (or, from after Clark Kent went into the molecule chamber) and driving in each morning.

There was an announced crowd of over 1,000 registered participants, which explains the occasional SRO crowds for some of the talks. Holding a conference of this size in a University setting forces a certain spatial distribution of the talks, so there were six parallel session in four different buildings. Add to that the talks being located along the southern part of the campus, while the parking garage and closest concentration of restaurants along the northern part, it made for a bit of walking. Which is a good thing, because the snacks that were provided was not exactly in the health-food category. One morning there was the matrix of donuts, including chocolate-covered ones covered with mini M&Ms (yes, it was tasty). There was also free beer at all of the poster sessions. Not surprisingly, these were well-attended. Too well, perhaps — the cacophony made it hard to hold a conversation at times, and it was tough to navigate the aisles.

Since I hadn’t been to this meeting since 2000, I’ve missed out on some of the incremental progress in many of the fields, so a lot was brand-new. The hot topics of today seem to include investigations into condensed-matter physics, with experiments using paired Fermions to form Bosons, and looking at the transition between Bose-Einstein Condensates and Cooper-Pair BCS superfluids. And a lot of talks about optical lattices, which now always seem to be far off-resonant traps.

Other than the Thesis Prize session, which included an atomic clock talk, and the optical frequency comb session, there weren’t a lot of talks that held any particular work-related interest for me, so I mostly stuck to a basic strategy of attending sessions that had invited talks; the speakers tend to give a bit of an overview which provides some context for the rest of the talk. That only failed me for last session, where five minutes of prep on cold molecule formation was not going to help me decipher what was going on.

Between my long absence, and that almost all of the atomic physics people I know being in the atomic clock field and not in attendance, I didn’t really know too many people at the meeting. I did re-introduce myself to a few people whom I know I had met, and I also waylaid a fellow blogger (one guess who that was) but, in turn, I was recognized by Arjendu. And I met people giving posters and at the banquet.

I had decided that driving back on Saturday afternoon was probably a Bad Idea™ and had arranged my motel accordingly. I ended up going to a local park on Saturday afternoon, surrounding a lake near the airport, and after clearing out the four geocaches, I spent a while filming wildlife in slow-motion.

Doctor Obvious Strikes Again

Brain research shows past experience is invaluable for complex decision making

Still, it’s good to get scientific results to corroborate this, because “conventional” wisdom isn’t always right, and then there’s the benefit of discovering details of the mechanism.

What we have found is that learning from past experience actually rewires our brains so that we can categorise the things we are looking at, and respond appropriately to them in any context.

Tracking the Roomba

Tracking that oh-so-elusive beast, the Roomba. Roomba’s Path Revealed

I set up a photo camera in my room, turned out all the lights and took a long-exposure shot of my roomba doing it’s thing for about 30 minutes. The result is a picture that shows the path of the roomba through it’s cleaning cycle, it looks like a flight map or something. It really hits every spot!

Harrison Wasn't a Solo Artist?

‘Lone’ longitude genius may have had help

The story of John Harrison the “lone genius” who solved the problem of finding longitude at sea is in urgent need of a rewrite.

Discoveries made during repairs to Harrison’s first successful “sea clock” – completed in 1735 – suggest that others contributed to his pioneering timepieces. “Harrison is always cast as a self-taught lone genius pitted against the establishment. The truth is, that is a great over-simplification,” says horologist Jonathan Betts of the Royal Observatory, Greenwich, London.

I think the idea that equating “lone genius” with “never talked to anyone about their work” is quite a reach. It’s been a while since I read Longitude, but I don’t recall having the impression that Harrison never sought out others to learn things. At what point are you no longer working alone? If you have a bottle-washer? If you don’t smelt your own brass?

Lily, Lily, Lily

Leeeeegs …

They start with Byron and Shelley
then jump on your belly
and bust your balloon.

Busting a water balloon. 1000 fps

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Seeing the Light

A Light Touch

Most familiar magnets are metals. They contain atoms that host tiny magnetic bar magnets, or moments, that can point up or down, and the atoms are surrounded by a sea of electrons. But researchers have long been interested in a different type of magnet, one consisting of widely separated magnetic ions embedded in a semiconductor. Unlike a metal, the number of free electrons in a semiconductor changes when it’s exposed to electric current or light, so these materials should provide new ways to influence the magnetic properties, via the electrons. Light can flip the magnetization–the total magnetic moment of atoms in a region–from up to down, for example. But until now, experimenters needed very bright light to weaken the magnetization enough to reorient it.