In fact, all of us have a piece of Chernobyl in our bodies going back to 1986.

The river of time may fork into rivers, in which case you have a parallel reality and so then you can become a time traveler and not have to worry about causing a time paradox.

If you want to see a black hole tonight, tonight just look in the direction of Sagittarius, the constellation. That's the center of the Milky Way Galaxy and there's a raging black hole at the very center of that constellation that holds the galaxy together.

I believe that science is the engine of prosperity, that if you look around at the wealth of civilization today, it's the wealth that comes from science.

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

There are dangers, but only dangers if people don't understand where technology is taking us.

You can mass-produce hardware; you cannot mass-produce software - you cannot mass-produce the human mind.