George Fitzgerald Smoot III
active c. 1945, Yukon, Florida, United States
American astrophysicist who led the DMR instrument on COBE that discovered the anisotropies of the cosmic microwave background — the 'seeds' of all cosmic structure.
Smoot earned his physics PhD at MIT in 1970 then switched to cosmology at Berkeley under Luis Alvarez. He measured the CMB dipole from a U-2 aircraft before proposing a satellite instrument.
As leader of the DMR (Differential Microwave Radiometer) on COBE, he announced in 1992 a map of the CMB's ~30 microkelvin temperature variations — 'wrinkles' in the infant sky that later grew into galaxies. He called it 'seeing the face of God' (Stephen Hawking called it 'the discovery of the century'). He shared the 2006 Nobel with John Mather.
Nobel-winning work
If the CMB were perfectly uniform, gravity could never have pulled matter into galaxies — the early universe had to be slightly lumpy. Yet ground and balloon measurements saw a suspiciously smooth sky; the dipole anisotropy from our Galaxy's motion had been measured at the 10⁻³ level, while the intrinsic anisotropies were hundreds of times smaller.
Smoot's DMR — three frequency channels to subtract Galactic contamination — mapped the whole sky and found temperature variations ΔT/T ~ 10⁻⁵, announced April 1992. The data precisely matched the Big Bang + quantum-inflation 'seed' model and measured a nearly scale-invariant spectrum — the foundation of cosmic structure formation. The 2006 Nobel cited 'the discovery of the blackbody form and anisotropy of the cosmic microwave background radiation'.
Workplaces: University of California, Berkeley
United States