Accurate and minute measurement seems to the non-scientific imagination, a less lofty and dignified work than looking for something new. But nearly all the grandest discoveries of science have been but the rewards of accurate measurement and patient long-continued labour in the minute sifting of numerical results.

If we can't express what we know in the form of numbers, we really don't know much about it.

Mathematics is the only good metaphysics.

When you can measure what you are speaking about, and express it in numbers, you know something about it.

Can you measure it? Can you express it in figures? Can you make a model of it? If not, your theory is apt to be based more upon imagination than upon knowledge.

[Of the ether] it is no greater mystery at all events than the shoemakers' wax.

Although mechanical energy is indestructible, there is a universal tendency to its dissipation, which produces throughout the system a gradual augmentation and diffusion of heat, cessation of motion and exhaustion of the potential energy of the material Universe