nasa decided to keep them up and bring them all down together. >> john: bill harwood, thanks, bill.again. the search for the fountain of youth, sorta. that's next on th "cbs evening cbs cares. >> john: the biblical figure methuselah is said to have lived the age of 969. no one has ever gotten close to matching that of course but year by year, scientists are learning more about the aging process. as cbs's charlie de mar reports. >> reporter: at 100 years old, william taylor hasn't lost a step. >> i've had my fun. >> reporter: dr. douglas vaughan wants to know why people like taylor are better at getting old. >> we are at a place where the biology of aging has been demystified. if we can slow down aging just a little bit, we can push back the onset of disease and we can give people a longer health span. >> reporter: the cardiologist is leading research into the difference between a person's chronological age, how many years they've lived, and their biological age, how old their body actually is. the foundation of his research came from a small amish community in indiana where he found