Ray Davis Dead at 91

The post title pretty much says it. Raymond Davis Jr., who shared the Nobel Prize in 2002 for his work on detecting neutrinos, died Wednesday. The Times obituatary showed up in my RSS feeds today.

Davis got his dynamite money for the neutrino detection experiment that he ran for years in the Homestake mine, where a giant tank of industrial cleaning fluid was placed so that an occasional neutrino would react with a chlorine atom and change it into an argon atom. Every few months, Davis would sift through the thousands of gallons of liquid to pull out tens or hundreds of argon atoms, and detect them. The number of argon atoms is a measure of the neutrino flux, and was the first experimental hint of the "Solar Neutrino Problem," and evidence of neutrino oscillations.

This is one of those absolutely boggling experiments that I'm amazed anybody actually thought was feasible. And, actually, a lot of people didn't think it would work, until Davis demonstrated it by putting a known amount of argon into his tank, and extracting it. It's a beautiful piece of work, and deserved a Nobel.