David Schramm, a leading authority on the birth of the universe, died on 19 December, after the private airplane he was piloting crashed outside Denver. Schramm, a 52-year-old astrophysicist and the research vice president at the University of Chicago, was flying from Chicago to his second home in Aspen, Colorado. The cause of the accident remains under investigation.
Schramm made his greatest scientific mark in weaving work on subatomic particles into the field of cosmology, the study of the universe's origin and structure. He helped explain the process by which the three lightest elements--hydrogen, helium, and lithium--were created immediately after the big bang. He and his collaborators also calculated the amount of ordinary matter in the universe, which helped demonstrate that the universe is dominated by invisible "dark matter." Schramm "was one of the major architects of our present model of the creation of the universe," says Nobel laureate Leon Lederman, a former director of the Fermi National Accelerator Laboratory, in Batavia, Illinois.
Schramm's most fundamental contribution to physics, perhaps, was a calculation in which he and other colleagues predicted that there are only three families of fundamental particles. Many physicists had expected that far more would be discovered. "We got a lot of flak from a lot of people," Schramm later said of the prediction in a book about cosmologists by Alan Lightman and Roberta Brower.
"He was excited about the latest results in theory or in experiment, and he always jumped to the next level of insight," said physicist John Bahcall, of the Institute for Advanced Study in Princeton, New Jersey. "His death is a huge loss," adds Lederman. "He was everywhere and very active, and thought very broadly about science and its role in society. He was ... always a leader."