Over time, the foundation shed its crankish air, turning its attention from trying to block gravity to trying to understand it. The annual essay prize has drawn respected researchers, including physicist Stephen Hawking, who won in 1971, mathematician/author Roger Penrose (Nobel Prize in Physics, 2020), who won in 1975, and astrophysicist and Nobel laureate George Smoot, who won in 1993. Other notable award winners include Jacob Bekenstein, Sidney Coleman, Bryce DeWitt, Julian Schwinger (Nobel Prize in Physics, 1965), Martin Perl (Nobel Prize in Physics, 1995), Demetrios Christodoulou, Dennis Sciama, Gerard 't Hooft (Nobel Prize in Physics, 1999), Robert Wald, John Archibald Wheeler and Frank Wilczek (Nobel Prize in Physics, 2004).