By Ron Cowen
New observations of the oldest light in the universe have enabled astronomers to determine the age of the cosmos with unprecedented precision, infer the existence of a vast sea of neutrinos, and better gauge the start and duration of the long-ago era when the first stars switched on.
The findings come from an analysis of 5 years of observations of the cosmic microwave background—the radiation left over from the Big Bang—using NASA’s Wilkinson Microwave Anisotropy Probe (WMAP).