Growing new organs of the body as they wear out, extending the human lifespan? What's not to like? Then in the last phase of this transition people begin to realize, hey, I thought of it already - this is something that everyone can enjoy.

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 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.

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

I had two passions when I was a child. First was to learn about Einstein's theory and help to complete his dream of a unified theory of everything. That's my day job. I work in something called string theory. I'm one of the founders of the subject. We hope to complete Einstein's dream of a theory of everything.

Today, your cell phone has more computer power than all of NASA back in 1969, when it placed two astronauts on the moon. Video games, which consume enormous amounts of computer power to simulate 3-D situations, use more computer power than mainframe computers of the previous decade. The Sony PlayStation of today, which costs $300, has the power of a military supercomputer of 1997, which cost millions of dollars.

Already from your own cells scientists can grow skin, cartilage, noses, blood vessels, bladders and windpipes. In the future, scientists will grow more complex organs, like livers and kidneys. The phrase 'organ failure' will disappear.