When I was 16 years old, I assembled a 2.3 million electron volt beta particle accelerator. I went to Westinghouse, I got 400 pounds of translator steel, 22 miles of copper wire, and I assembled a 6-kilowatt, 2.3 million electron accelerator in the garage.

I'm a physicist, and we have something called Moore's Law, which says computer power doubles every 18 months. So every Christmas, we more or less assume that our toys and appliances are more or less twice as powerful as the previous Christmas.

In some sense, gravity does not exist; what moves the planets and the stars is the distortion of space and time.

We're in 'Jurassic Park' territory. If we go to the zoo in the future, we'll have zoos for extinct animals.

The human brain has 100 billion neurons, each neuron connected to 10 thousand other neurons. Sitting on your shoulders is the most complicated object in the known universe.

I think a colony in space will take much longer than sci fiction writers think. It costs $10,000 to put a pound of anything into near earth orbit. That is your weight in gold. It costs about $100,000 a pound to put you on the moon. And it costs $1,000,000 a pound to put you on Mars.

Even if we mortgage the next 100 years of generations of human beings, we would not have enough energy to build a Death Star.