I got a four year scholarship to Harvard, and while I was there they wanted to groom me for work in the Star Wars program designing weapons ignited by hydrogen bombs. I didn't want to do that. I thought about how many scientists had died in World War II.

I agree, along with Carl Sagan, that we should eventually become a two planet species. Life is too precious to place on a single planet.

I would like to believe that crop circles are evidence of visitation. But there have been too many people who have admitted to creating these crop circles, and too many people who have shown how to make one on TV programs, so I have my doubts.

A force field is basically an invisible shield. You push a button and all of a sudden a bubble forms around you which is impenetrable. It can stop bullets, it can stop ray gun blasts and we realized force fields are actually a little bit difficult to create.

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

What differentiates human from lower-animal consciousness is time. You can't explain the concept of "tomorrow" to your dog. Our consciousness is dominated by time - We're constantly running simulations of the future. Our brain is a prediction machine. The hallmark of intelligence, indeed of genius, is the number and complexity of the feedback loops we use in predicting the future.

In physics, one of the most exciting areas is in nanotech. With computers exhausting the power of silicon, Silicon Valley could become a Rust Belt, unless we can find replacements, such as quantum computers and molecular computers. To be a leader in any field, one has to have a great imagination. Sure, we have to know the basics and fundamentals. But beyond that, we have to let our imagination soar.