The physicist Andrew E. Lange, who died, apparently by his own hand, on 22 January aged 52, was co-leader of an international team that produced a detailed image of remnants of the Big Bang showing that the universe is flat.
Lange was best known as co-leader of project "Boomerang", which in 1998 used a telescope, carried over Antarctica by a balloon for 10 days, to study cosmic microwave background, a gas of thermal radiation left over from the embryonic universe. The experiment showed that the spatial geometry of the universe is flat and supported theories that it will expand forever and not collapse upon itself.
Lange, who had three young sons, was born in 1957 in Illinois. He graduated from Princeton, received a Ph.D. from the University of California, Berkeley, and was appointed professor at Caltech in 1994. In 2006, he became a senior research scientist at NASA's Jet Propulsion Laboratory and was appointed chairman of Caltech's physics, mathematics and astronomy division in 2008.