Mather, John Cromwell (1946– )

US cosmologist and astrophysicist. He shared the Nobel Prize for Physics in 2006 with US astrophysicist George F Smoot for their contributions to the discovery of temperature variations and the black body form of the cosmic microwave background radiation.

The Big Bang theory predicts that in its earliest stages following the event, the universe emitted a cosmic background of microwave radiation that had the same characteristics and shape as the spectrum of radiation emitted from a black body. As the universe expanded, this radiation cooled from its original temperature of 3,000°C to its present value of 2.7°C above absolute zero. Mather proposed the Cosmic Background Explorer (COBE) satellite programme to detect the cosmic microwave background radiation remnants and led the team at Goddard Space Flight centre that measured the spectrum of the microwave background confirmed that it had the properties of black body radiation. The discovery lends support to the Big Bang theory.

Mather was born in Roanoke, Virginia. He studied physics at the University of California at Berkeley, California, gaining his PhD in 1974. He became a member of the National Academy of Sciences, US, in 1997 and was awarded a fellowship in the American Academy of Arts and Sciences in 1998. He is a senior astrophysicist at the Observation Cosmology Laboratory at NASA's Goddard Space Flight Centre, Greenbelt, Maryland.