The Download: eternal youth, and the hunt for new metals

A little over 15 years ago, scientists at Kyoto University in Japan made a remarkable discovery. When they added just four proteins to a skin cell and waited about two weeks, some of the cells underwent an unexpected and astounding transformation: they became young again. They turned into stem cells almost identical to the kind found in a days-old embryo, just beginning life's journey. At least in a petri dish, researchers using the procedure can take withered skin cells from a 101-year-old and rewind them so they act as if they'd never aged at all. Now, after more than a decade of studying and tweaking so-called cellular reprogramming, a number of biotech companies and research labs say they have tantalizing hints that the process could be the gateway to an unprecedented new technology for age reversal.