The more you learn, the more you know. The more you know, the more you forget. The more you forget, the less you know. So why bother to learn.

The human race is just a chemical scum on a moderate-sized planet, orbiting around a very average star in the outer suburb of one among a hundred billion galaxies. We are so insignificant that I can't believe the whole universe exists for our benefit. That would be like saying that you would disappear if I closed my eyes.

Simplicity is a matter of taste

Science can lift people out of poverty and cure disease. That, in turn, will reduce civil unrest.

In real time, the universe has a beginning and an end at singularities that form a boundary to space-time and at which the laws of science break down.

The doctor who diagnosed me with ALS, or motor neuron disease, told me that it would kill me in two or three years.

It is tribute to how far we have come in theoretical physics that it now takes enormous machines and a great deal of money to perform experiments whose results we can not predict.