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.

Should a young scientist working with me come to me after two years of such work and ask me what to do next, I would advise him to get out of science. After two years of work, if a man does not know what to do next, he will never make a real scientist.

Radioactivity is shown to be accompanied by chemical changes in which new types of matter are being continually produced. .... The conclusion is drawn that these chemical changes must be sub-atomic in character.

[From uranium] there are present at least two distinct types of radiation one that is very readily absorbed, which will be termed for convenience the α radiation, and the other of a more penetrative character, which will be termed the β radiation.

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.

A good scientific theory should be explicable to a barmaid.

It is essential for men of science to take an interest in the administration of their own affairs or else the professional civil servant will step in - and then the Lord help you.