Walter Kohn, physicist/chemist and 1998 Nobel laureate in chemistry, passed away Tuesday evening at the age of 93. His prize-winning work is the basis for pretty much all of quantum chemistry (quantitative understanding of how electrons are distributed in molecules and how molecules are put together) and a major influence on the development of supercomputing. Obituary is here.
On a personal note, I was just starting grad school at his university when the won the prize, which he handled with more humility and grace than the handful of other laureates I've seen up close. While I didn't work in his field, I witnessed him stop (on the spur of the moment) to talk to and teach other graduate students, even though he was retired and undoubtedly busy with the flood of requests that tend to come with the Nobel. He also continued riding the bus to work after winning the prize. Just a really down-to-earth, generous person, so much less pretentious than many less-justified individuals. The world is a little worse off every time we lose someone like him.