Today we are rightly in an era of disarmament and dismantlement of nuclear weapons. But in some countries nuclear weapons development still continues. Whether and when the various Nations of the World can agree to stop this is uncertain. But individual scientists can still influence this process by withholding their skills.

If we fight a war and win it with H-bombs, what history will remember is not the ideals we were fighting for, but the methods we used to accomplish them. These methods will be compared to the warfare of Genghis Khan who ruthlessly killed every last inhabitant of Persia.

No one any longer pays attention to - if I may call it - the spirit of physics, the idea of discovery, the idea of understanding. I think it's difficult to make clear to the non-physicist the beauty of how it fits together, of how you can build a world picture, and the beauty that the laws of physics are immutable.

Stars have a life cycle much like animals. They get born, they grow, they go through a definite internal development, and finally they die, to give back the material of which they are made so that new stars may live

I am not a philosopher.

Finally I got to carbon, and as you all know, in the case of carbon the reaction works out beautifully. One goes through six reactions, and at the end one comes back to carbon. In the process one has made four hydrogen atoms into one of helium. The theory, of course, was not made on the railway train from Washington to Ithaca ... It didn't take very long, it took about six weeks, but not even the Trans-Siberian railroad [has] taken that long for its journey.

I call on all scientists in all countries to cease and desist from work creating, developing, improving and manufacturing further nuclear weapons - and, for that matter, other weapons of potential mass destruction such as chemical and biological weapons.