- Here is a video of Richard Feynman, explaining why he can't readily explain permanent magnets to the interviewer. This gets right to the heart of why explaining science in a popular, accessible way can be very difficult. Sure, he could come up with really stretched and tortured analogies, but truly getting at the deeper science behind the permanent magnets and their interactions would require laying a ton of groundwork, way more than what an average person would want to hear.
- Here is a freely available news article from Nature about superconductivity in H2S at very high pressures. I was going to write at some length about this but haven't found the time. The short version: There have been predictions for a long time that hydrogen, at very high pressures like in the interior of Jupiter, should be metallic and possibly a relatively high temperature superconductor. There are later predictions that hydrogen-rich alloys and compounds could also superconduct at pretty high temperatures. Now it seems that hydrogen sulfide does just this. Crank up the pressure to 1.5 million atmospheres, and that stinky gas becomes what seems to be a relatively conventional (!) superconductor, with a transition temperature close to 200 K. The temperature is comparatively high because of a combination of an effectively high speed of sound (the material gets pretty stiff at those pressures), a large density of electrons available to participate, and a strong coupling between the electrons and those vibrations (so that the vibrations can provide an effective attractive interaction between the electrons that leads to pairing). The important thing about this work is that it shows that there is no obvious reason why superconductivity at or near room temperature should be ruled out.
- Congratulations to Prof. Laura Greene, incoming APS president, who has been named the new chief scientist of the National High Magnetic Field Lab.
- Likewise, congratulations to Prof. Meigan Aronson, who has been named Texas A&M University's new Dean of Science.
Monday, August 24, 2015
News items: Feynman, superconductors, faculty shuffle
A few brief news items - our first week of classes this term is a busy time.
Posted by Douglas Natelson at 9:51 PM