How old is the universe

A new determination has been made of the age of the universe based upon the use of the rhenium-osmium beta-decay clock. The crucial experimental element in this determination was the measurement of the neutron-capture cross sections for osmium-186 and osmium-187, in the energy range corresponding to stellar temperatures. The use of this clock gives a value for the time elapsed between the formation of the Milky Way and the condensation of the solar system, the period during which the present matter of the solar system was undergoing nucleosynthesis in the interior of stars. Including reasonable assumptions and incorporating appropriate uncertainties, the determination of the age of the universe is 17 +- 3 billion years. This value, although significantly larger than the results of previous determinations, agrees with the age of recently discovered galaxies. It is greater, however, than the apparent limit set by the most recent determination of the Hubble time. This difference has implications of crucial significance for cosmology