A million million million million (1 with twenty-four zeros after it) miles, the size of the observable universe.

For years, my early work with Roger Penrose seemed to be a disaster for science. It showed that the universe must have begun with a singularity, if Einstein's general theory of relativity is correct. That appeared to indicate that science could not predict how the universe would begin.

One can't prove that God doesn't exist. But science makes God unnecessary. The laws of physics can explain the universe without the need for a creator.

There ought to be something very special about the boundary conditions of the universe and what can be more special than that there is no boundary?

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.

Life on Earth is at the ever-increasing risk of being wiped out by a disaster, such as sudden global warming, nuclear war, a genetically engineered virus or other dangers. I think the human race has no future if it doesn't go into space. I therefore want to encourage public interest in space.

I don't know what my IQ is. People who gloat about their IQ's are losers