Saul Perlmutter, an astrophysicist at the University of California at Berkeley, received the 2011 Nobel Prize in Physics for his study of supernovae which showed that the rate of expansion of the universe is not being slowed down by gravitational forces, as previously believed, but is actually speeding up. The implication is that a mysterious force called "dark energy" is responsible for this accelerating rate of expansion.
Some people who heard this news may not know that Saul Perlmutter's father is
a member of PASEF and a Professor Emeritus in Chemical and Biomolecular Engineering at the University of Pennsylvania. The Perlmutter family lived in the West Mount Airy section of Philadelphia and Saul attended Germantown Friends School.
Dan's field of research is chemical process control and chemical reaction engineering; his most recent publication (with Robert Rothstein) is the
entitled "The Challenge of Climate Change: Which Way Now", Wiley, 2011.