Until roughly the 20th century, physics was concerned with the realities of ordinary experience: light, heat and sound; motion, acceleration, falling bodies; gases, fluids, solids; electricity, magnetism and so on and so forth through the world of phenomena. Then in 1895, Wilhelm Roentgen discovered X-rays; in 1897, J.J. Thompson discovered the electron; in 1914, Rutherford discovered the proton - and all at once a new branch of physics had come into existence: elementary particle theory, dealing with the hidden realities, the fundamental entities that underlie the observed phenomena of everyday life.

LRB 24 June 1993 | PDF Download