7 John Stewart Bell Quotes

John Stewart Bell quotes

1. Theoretical physicists live in a classical world, looking out into a quantum-mechanical world. The latter we describe only subjectively, in terms of procedures and results in our classical domain.

2. The concept of 'measurement' becomes so fuzzy on reflection that it is quite surprising to have it appearing in physical theory at the most fundamental level... does not any analysis of measurement require concepts more fundamental than measurement? And should not the fundamental theory be about these more fundamental concepts?

3. While the founding fathers agonized over the question 'particle' or 'wave', de Broglie in 1925 proposed the obvious answer 'particle' and 'wave'. Is it not clear from the smallness of the scintillation on the screen that we have to do with a particle? And is it not clear, from the diffraction and interference patterns, that the motion of the particle is directed by a wave? De Broglie showed in detail how the motion of a particle, passing through just one of two holes in screen, could be influenced by waves propagating through both holes. And so influenced that the particle does not go where the waves cancel out, but is attracted to where they cooperate. This idea seems to me so natural and simple, to resolve the wave-particle dilemma in such a clear and ordinary way, that it is a great mystery to me that it was so generally ignored.

4. Is it not good to know what follows from what, even if it is not necessarily FAPP? [FAPP is Bell's suggested abbreviation of 'for all practical purposes.'] Suppose for example that quantum mechanics were found to resist precise formulation. Suppose that when formulation beyond FAPP was attempted, we find an unmovable finger obstinately pointing outside the subject, to the mind of the observor, to the Hindu scriptures, to God, or even only Gravitation? Would that not be very, very interesting?

1. No theory of reality compatible with quantum theory can require spatially separate events to be independent.

2. I am a Quantum Engineer, but on Sundays I Have Principles.

3. Long may Louis de Broglie continue to inspire those who suspect that what is proved by impossibility proofs is lack of imagination.