selfless examples in the annals of science. Newton began almost immediately to reap the rewards of prominence; Halley received little credit. He did use the principles to predict the orbit and return of the comet that would later bear his name, but only after his death did he received any acclaim. And because the comet only returns every seventy-six years, the notice is rather infrequent. Halley remained a devoted scientist who didn’t care who received the credit as long as the cause was being advanced.