Those who do not stop asking silly questions become scientists.

I sometimes think about the tower at Pisa as the first particle accelerator, a (nearly) vertical linear accelerator that Galileo used in his studies.

Theorists 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.

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.

The real goal of physics is to come up with an equation that could explain the universe but still be small enough to fit on a T-shirt

Physics isn't a religion. If it were, we'd have a much easier time raising money.

When 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.