A physicist was a scientist who studied the nature of matter, energy and force, as well as their motion through space and time. Such studies ranged from the sub-atomic to the macrocosmic.
The English physicist and mathematician Sir Isaac Newton was famous for formulating the theory of gravity. The Fourth Doctor once claimed that he sat in Newton's tree dropping apples onto his head, then explained gravity to him over dinner. (TV: The Pirate Planet)
Aaron Blinovitch was a temporal physicist on Earth and the author of the book Temporal Mechanics. The Blinovitch Limitation Effect was named for him. He was also a member of Faction Paradox. (PROSE: Unnatural History) He conceived of the Blinovitch Limitation Effect in 1928 while in the Reading Room of the British Museum (PROSE: The Ghosts of N-Space)