In the last 200 years the population of our planet has grown exponentially, at a rate of 1.9% per year. If it continued at this rate, with the population doubling every 40 years, by 2600 we would all be standing literally shoulder to shoulder.

Do you believe in first love - or should I pass by again?

Many people do not like the idea that time has a beginning, probably because it smacks of divine intervention.

If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans.

"Sooner or later disasters such as an asteroid collision or a nuclear war could wipe us all out, But once we spread out into space and establish independent colonies, our future should be safe."

All of my life, I have been fascinated by the big questions that face us, and have tried to find scientific answers to them. If, like me, you have looked at the stars, and tried to make sense of what you see, you too have started to wonder what makes the universe exist.

There is a real danger that computers will develop intelligence and take over. We urgently need to develop direct connections to the brain so that computers can add to human intelligence rather than be in opposition.