3. Mordehai Milgrom: 61, Weizmann Institute, Israel. Body of work: His modified Newtonian dynamics (MOND) says gravity does not follow Newton’s laws when it is very weak. MOND explains the strange rotation of galaxies without positing the existence of dark matter. But it does not unify gravity with quantum theory. Einsteinian trait: Came up with MOND at the Institute for Advanced Study, Einstein’s old stomping grounds.
4. Giovanni Amelino-Camelia: 42, University of Rome–Sapienza, Italy. Body of work: His “doubly special relativity” posits that the supposedly constant speed of light actually depends on its wavelength and that space has a minimum distance. His theory could unify physics and help explain the early growth of the universe, but experimental proof seems to be a tall order. Einsteinian trait: Rejects accepted physics on the basis of logic arguments.
5. Fotini Markopoulou-Kalamara: 36, Perimeter Institute for Theoretical Physics, Canada. Body of work: Works on loop quantum gravity, which says abstract loops compose matter and space. This theory has derived some real physical properties from pure math; it quantifies what space is and unifies quantum and gravitational realms, but it is short on experimental proof. Einsteinian trait: As a child Markopoulou-Kalamara dreamed of being almost anything but a physicist.
6. Ed Witten: 56, Institute for Advanced Study, New Jersey. Body of work: Godfather of string theory; instrumental in creating M theory, which unites various string theories. M theory has no hard proof, raising the possibility that it is only an extremely difficult version of sudoku. Einsteinian trait: His otherworldly intelligence leads some to joke that he is an alien, a charge also leveled at Einstein.
