Daily Archives: June 28, 2010

No Cross-Dressers They

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Do bosons ever masquerade as fermions?

Bosons can pile on top of one another without limit, all occupying the same quantum state. At low temperatures, this causes such strange phenomena as superconductivity, superfluidity and Bose-Einstein condensation. It also allows photons of the same frequency to form coherent laser beams. Fermions, on the other hand, avoid one another. Electrons around a nucleus stack into shells instead of collapsing into a condensed cloud, giving rise to atoms with a great range of chemical properties.
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“If just one pair of photons out of 10 billion had taken the bait and behaved like fermions, we would have seen it,” English said. “Photons are bosons, at least within our experimental sensitivity.”

I'll Bet They've Got SCMODS

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The Physics of the Blues Brothers

At the time the movie was released, it had more car crashes than any movie in history and was only surpassed by the sequel. They bought 60 police cruisers to repeatedly destroy and kept a 24hr body shop to repair them. They went through 13 “Bluesmobiles,” to do all the stunts. Some were retrofitted with tiny one gallon gas tanks for jumping, others modified for speed and one took a mechanic several months to rig just so it would fall to pieces in the final scene. While they might not seem so impressive in our age of rampant CGI, all the stunts in the movie were real.

Don't Make Them Feel Self-Conscious

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Weird Antimatter Particles Discovered Deep Underground

Don’t call them weird — they aren’t. They violate parity, but that makes them special. As far as I can tell (and it isn’t easy, because the press releases and web pages do a kinda crappy job of this), the so-called geoneutrinos are electron neutrinos, given off in decay chains of heavy elements in the earth’s interior. More specifically, they would be antineutrinos, since the decay chains typically involve alpha and beta-minus decays, and the latter give off electron antineutrinos.

In other words, the particle is not new. The name distinguishes them from solar neutrinos, but I think it also adds confusion to the mix, especially when the distinction isn’t made clear. Unnecessary jargon isn’t a good thing.

What is interesting is that the scientists are trying to use this as a diagnostic for learning about the earth’s interior.

The researchers hope that by studying geoneutrinos, they can learn more about how decaying elements add to the heat beneath Earth’s surface and affect processes like convection in the mantle. Whether radioactive decay dominates the heating in this layer, or merely adds to the heat from other sources, is an open question.