THE AGE OF THE UNIVERSE

Astronomers have two approaches to trying to determine the age of the Universe. They can estimate the ages of individual objects in the Univ erse and specifically in our Galaxy. These estimates use either the ob served properties of stars and theoretical ideas concerning stellar ev olution or the abundances of long-lived radioactive isotopes and their decay products. Alternatively they can use cosmological theories and observations to try to determine the age of the entire Universe. Obvio usly the Universe must be older than its component parts but neither o f the above methods is sufficiently reliable that this is true of the deduced ages. As a result, it is from time to time reported that some object in the Universe is older than the Universe itself. In this arti cle lye discuss the methods that are currently being used to determine the age and we emphasize the problems in obtaining reliable results. It is not at present possible to provide a definite value for the age of the Universe.