Life-Line

Life-Line is Heinlein's first published science fiction story (1939), about a man who builds a machine that will predict how long a person will live. Professor Pinero's invention has a powerful impact on the life insurance industry, as well as on his own life. Pinero is mentioned in passing in the novel Time Enough for Love when immortal Lazarus Long mentions having been examined and being sent away because the machine is "broken".