To a physicist, we have the 'I' word, the I-word is 'impossible.' That's dangerous.

There are so many wonders awaiting us. If we can upload memories, then we might be able to combat Alzheimers, as well as create a brain-net of memories and emotions to replace the internet, which would revolutionize entertainment, the economy, and our way of life. Maybe even to help us live forever, and send consciousness into outer space.

Once again, my colleague Stephen Hawking has upset the apple cart. The event horizon surrounding a black hole was once though to be an imaginary sphere. But recent theories indicate that it may actually be physical, maybe even a sphere of fire. But I don't trust any of these calculations until we have a full-blown string theory calculation, since Einstein's theory by itself is incomplete.

The energy necessary to create a wormhole or to wrap time into nuts is incredible. It's not for us. It's maybe for our descendants who have mastered the energy of this technology. So if one day, somebody knocks on your door and claims to be your great great great great granddaughter, don't slam the door.

A soul might very well exist, but we, as physicists, try to measure and quantify everything. So far, no one has been able to create an experiment to do this for the soul. Efforts have been made to weigh the body after death, but each time we find no evidence of a soul. So a soul may very well exist, but it is not a testable theory.

We can summarize electricity, magnetism and gravity into equations one inch long, and that's the power of field theory. And so I said to myself: I will create a field theory of strings. And when I did it one day, it was incredible, realizing that on a sheet of paper I can write down an equation which summarized almost all physical knowledge.

The most likely possibility, favored by current data, is that the universe will die in Ice, not Fire. However, personally I believe that trillions of years from now, we (if we are still around) will have the technology to leave the universe, perhaps in an interdimensional life boat, and move to a warmer universe.