To understand the difficulty of predicting the next 100 years, we have to appreciate the difficulty that the people of 1900 had in predicting the world of 2000.

To become a theoretical physicist ... you need to have a passionate love affair with the universe.

What we usually consider as impossible are simply engineering problems... there's no law of physics preventing them.

The most complex object in the known universe: brain, only uses 20 watts of power. It would require a nuclear power plant to energize a computer the size of a city block to mimic your brain, and your brain does it with just 20 watts. So if someone calls you a dim bulb, that's a compliment.

Modern thinking is that time did not start with the big bang, and that there was a multiverse even before the big bang. In the inflation theory, and in string theory, there were universes before our big bang, and that big bangs are happening all the time. Universes are formed when bubbles collide or fission into smaller bubles.

The brain weighs only three pounds, yet it is the most complex object in the solar system.

Robots may gradually attain a degree of 'self-awareness' and consciousness of their own.