Popular Scientific Lectures

A round raindrop becomes a problem in physics when Ernst Mach asks whether liquids have shapes of their own. His opening lecture challenges familiar distinctions between liquids and solids, then describes an experiment that suspends oil in a mixture of equal density to remove the effect of its weight. The collection moves from such concrete demonstrations to hearing, harmony, light, binocular vision, symmetry and the conservation of energy.

Mach also examines the habits of thought behind scientific discovery. He explains how comparison with a familiar phenomenon can make a new observation easier to understand, while warning that an attractive theory may obstruct further inquiry. Translated by Thomas J. McCormack, these lectures combine physical examples with reflections on knowledge and education. They offer readers interested in the history of science a close view of how experiments, analogies and ordinary reasoning work together.