The role of radioactive isotopes in astrophysics

Abstract

Radioactive nuclei can not be not infinitely old or they would now be gone. This point had first been made Rutherford, E. by Lord Rutherford, who concluded in 1929 (Rutherford 1929) that the elements had been created in the sun 100 million years ago and had somehow got from sun to earth! Terrible astrophysics, but his argument showed profound appreciation of the conundrum of live radioactivity on earth; namely, the nuclei must be created. By the middle of the twentieth century, the consequences had progressed no further. The question, "Why aren't they all gone?" went largely unspoken.