Once you can reproduce a phenomenon, you are well on the way to understanding it.

In my life I have found two things of priceless worth - learning and loving. Nothing else - not fame, not power, not achievement for its own sake - can possible have the same lasting value. For when your life is over, if you can say 'I have learned' and 'I have loved,' you will also be able to say 'I have been happy.

Creationism, perhaps the most pernicious of the intellectual perversions now afflicting the American public.

Never attribute to malevolence what is merely due to incompetence

The future is not to be forecast, but created.

What was more, they had taken the first step toward genuine friendship. They had exchanged vulnerabilities.

I'm sometimes asked how I would like to be remembered. I've had a diverse career as a writer, underwater explorer, space promoter and science populariser. Of all these, I want to be remembered most as a writer - one who entertained readers, and, hopefully, stretched their imagination as well.