An electron is no more (and no less) hypothetical than a star. Nowadays we count electrons one by one in a Geiger counter, as we count the stars one by one on a photographic plate.

Whatever else there may be in our nature, responsibility toward truth is one of its attributes.

We have found that where science has progressed the farthest, the mind has but regained from nature that which the mind put into nature.

In the most modern theories of physics probability seems to have replaced aether as "the nominative of the verb 'to undulate'."

Our ultimate analysis of space leads us not to a "here" and a "there," but to an extension such as that which relates "here" and "there." To put the conclusion rather crudely-space is not a lot of points close together; it is a lot of distances interlocked.

If I let my fingers wander idly over the keys of a typewriter it might happen that my screed made an intelligible sentence. If an army of monkeys were strumming on typewriters they might write all the books in the British Museum. The chance of their doing so is decidedly more favourable than the chance of the molecules returning to one half of the vessel.

The mathematics is not there till we put it there.