The 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. LedermanA 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. LedermanTheorists write all the popular books on science: Heinz Pagels, Frank Wilczek, Stephen Hawking, Richard Feynman, et al. And why not? They have all that spare time.
Leon M. LedermanTheorists tend to peak at an early age; the creative juices tend to gush very early and start drying up past the age of fifteen-or so it seems. They need to know just enough; when they're young they haven't accumulated the intellectual baggage.
Leon M. LedermanThe history of atomism is one of reductionism โ the effort to reduce all the operations of nature to a small number of laws governing a small number of primordial objects.
Leon M. LedermanWhen I talk about the pain and hardship of a scientist's life, I'm speaking of more than existential angst. Galileo's work was condemned by the Church; Madame Curie paid with her life, a victim of leukemia wrought by radiation poisoning. Too many of us develop cataracts. None of us gets enough sleep. Most of what we know about the universe we know thanks to a lot of guys (and ladies) who stayed up late at night.
Leon M. Lederman