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.

My children have often asked me why I never received a Nobel Prize. I used to tell them it was because the Nobel committee couldn’t make up its mind which of my projects to recognize.

One of the major ingredients for professional success in science is luck. Without this, forget it.

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.

We hope to explain the entire universe in a single, simple formula that you can wear on your T-shirt.

I started out as a molecules kid. In high school and early college I loved chemistry, but I gradually shifted toward physics, which seemed cleaner - odorless, in fact.

I'm so old I can remember when the Dead Sea was only sick.