I am a great believer in the simplicity of things and as you probably know I am inclined to hang on to broad & simple ideas like grim death until evidence is too strong for my tenacity.

The great object is to find the theory of the matter [of X-rays] before anyone else, for nearly every professor in Europe is now on the warpath.

Don't let me catch anyone talking about the Universe in my department.

I congratulate you both on a fine piece of work which I am sure will ultimately prove of importance. I am personally very much interested in your results... In the past I have tried a number of experiments... but without any success.

Splitting the atom is like trying to shoot a gnat in the Albert Hall at night and using ten million rounds of ammunition on the off chance of getting it. That should convince you that the atom will always be a sink of energy and never a reservoir of energy.

I've just finished reading some of my early papers, and you know, when I'd finished I said to myself, 'Rutherford, my boy, you used to be a damned clever fellow.' (1911)

All of physics is either impossible or trivial. It is impossible until you understand it, and then it becomes trivial.