A younger age for the universe

The age of the universe in the Big Bang model can be calculated from three parameters: Hubble's constant, h; the mass density of the universe, Omega(m ); and the cosmological constant, Omega(Lambda). Recent observations of the cosmic microwave background and six other cosmological measurements reduce the uncertainty in these three parameters, yielding an age for the univers e of 13.4 +/- 1.6 billion years, which is a billion years younger than othe r recent age estimates. A different standard Big Bang model, which includes cold dark matter with a cosmological constant, provides a consistent and a bsolutely time-calibrated evolutionary sequence for the universe.