Everyone can enjoy a life of luxurious leisure if the machine-produced wealth is shared, or most people can end up miserably poor if the machine-owners successfully lobby against wealth redistribution.

My first popular book, 'A Brief History of Time,' aroused a great deal of interest, but many found it difficult to understand.

One does not have to appeal to God to set the initial conditions for the creation of the universe, but if one does He would have to act through the laws of physics.

A few years ago, the city council of Monza, Italy, barred pet owners from keeping goldfish in curved bowls... saying that it is cruel to keep a fish in a bowl with curved sides because, gazing out, the fish would have a distorted view of reality. But how do we know we have the true, undistorted picture of reality?

If it were only a few degrees, that would be serious, but we could adapt to it. But the danger is the warming process might be unstable and run away. We could end up like Venus, covered in clouds and with the surface temperature of 400 degrees. It could be too late if we wait until the bad effects of warming become obvious. We need action now to reduce emission of carbon dioxide.

I have to speak through a computer... in my mind, I am free. Free to explore the universe and ask the big questions...

I wouldnt be here today if it were not for the NHS, I have received a large amount of high-quality treatment without which I would not have survived.