Energy and Technology Review

Abstract

The Veil Nebula, a supernova remna.it (pho tograph courtesy of the Hale Observatory). Cur rent theory holds that the universe began with a Big Bang and the galaxies formed shortly t> ireafter. The age of our solsr system is knoivn well, but the age of our galaxy, the Milky Way, is not. However, the heavier elements in the Milky Way originated in supcrnovae such as the one that produced the Veil. Therefore, we may estimate the age of the universe by determining the dura tion of nucleosynthesis, i.e., the length of the pe riod during which the matter of which our solar system is composed was being processed in the stars. This determination is provided by nucleardating techniques based upon the knowledge of the relative isotopic abundances and the decay rates of the nuclear species used in dating. How ever, the use of such a technique depends criti cally upon the knowledge of the cross section for the neutron-capture reactions which create and destroy these key nuclear species in a stellar environment. Yor information about a new mea surement of the key cross sec'ums which are nec-ess&iv for determining the age of the inverse, see the article beginning on p. I.