Astronauts have been stuck in low-Earth orbit, boldly going nowhere. American attempts to kick-start a new phase of lunar exploration have stalled amid the realisation that NASA's budget is too small for the job.

When I was a student, the laws of physics were regarded as completely off limits. The job of the scientist, we were told, is to discover the laws and apply them, not inquire into their provenance.

No planet is more earth-like than Earth itself, so if life really does pop up readily in earth-like conditions, then surely it should have arisen many times right here on our home planet? And how do we know it didn't? The truth is, nobody has looked.

Should we find a second form of life right here on our doorstep, we could be confident that life is a truly cosmic phenomenon. If so, there may well be sentient beings somewhere in the galaxy wondering, as do we, if they are not alone in the universe.

As a company, we don't contribute to any cause except noncontroversial things like a breast cancer walk. I don't know anybody who is 'for' breast cancer.

The world cannot continue to build larger health care systems where you just sit around and wait for people to get sick.

I was a vegan for about a year, and it was a great experience. And I became vegan not because of animal rights. I became vegan for a year for health purposes... It was just kind of a detox that I was going through.

Some of the best health care services are free or cost very little and are even available to millionaires but hardly anyone knows they exist.