Cosmologists are a small, elite fraternity whose work informs our knowledge of the cosmos at the highest, grandest levels.
But their close-knit universe was rocked this past weekend as word spread of the sudden death of Andrew Lange. Although not mentioned in the brief announcement posted by Caltech, where until recently he'd served as chairman of its Physics, Mathematics, and Astronomy Division, he had struggled with personal issues and apparently took his own life.
Although I never met Lange in person, I've been keenly aware of his importance to our understanding of the early universe. Most notably, he was co-leader of the Boomerang project that used a balloon-borne telescope, launched from Antarctica, to map the detailed structure of the cosmic microwave background. These whispers of microwave energy are the slowly dying echoes of the primordial fireball unleashed during the Big Bang.
Lange's observations with Boomerang measured the angular size of subtle variations within the CMB and led to the realization that the infant universe assumed a flat geometry after an initially rapid growth spurt due to inflation.
Boomerang's results followed closely on the heels of a breakthrough by two teams, led respectively by Adam Riess and Saul Perlmutter (both at University of California, Berkeley), who found that distant galaxies are moving away from us at ever-greater speeds and that the flat universe must be permeated with a type of negative gravitational pressure — often dubbed "dark energy."
After spending six years as an assistant professor at UC Berkeley, Lange arrived at Caltech to stay in 1993 and soon distinguished himself as one of its leading scientists (in a place where just about everyone is a leading scientist). In 2003 he and Perlmutter were jointly named "California Scientists of the Year" by the California ScienCenter. The following year Lange was elected to the U.S. National Academy of Sciences.
On Saturday, in an address emailed to the Caltech community, president Jean-Lou Chameau noted, "Among the most difficult things that people have to deal with in life are tragedies of this sort, especially when they affect people that we know and care for; and Andrew was such a well-known, well-respected, and well-liked member of our community that many of us will be deeply affected."
Click here to watch a lecture given by Lange, just last November, on how the universe began.