A theoretical physicist can spend his entire lifetime missing the intellectual challenge of experimental work, experiencing none of the thrills and dangers - the overhead crane with its ten-ton load, the flashing skull and crossbones and danger, radioactivity signs. A theorist's only real hazard is stabbing himself with a pencil while attacking a bug that crawls out of his calculations.
Leon M. LedermanNeutrinos ... win the minimalist contest: zero charge, zero radius, and very possibly zero mass.
Leon M. LedermanThe physicists defer only to mathematicians, and the mathematicians defer only to God.
Leon M. LedermanThe aether: Invented by Isaac Newton, reinvented by James Clerk Maxwell. This is the stuff that fills up the empty space of the universe. Discredited and discarded by Einstein, the aether is now making a Nixonian comeback. It's really the vacuum, but burdened by theoretical, ghostly particles.
Leon M. Lederman