We live in a world of waves. The Earth shakes to its foundations, the seas and oceans tremble incessantly, sounds reverberate through land, sea, and air. Beneath the skin, our brains and bodies are awash with waves of their own, and the Universe is filled by a vast spectrum of electromagnetic radiation, of which visible light is the narrowest sliver. There are also mechanical waves, quantum wave phenomena, and gravitational waves. Waves: A Very Short Introduction considers waves of all kinds, their sources, effects, and uses. It discusses how wave motion results in a range of phenomena—from reflection, diffraction, interference, and polarization in the case of light waves to beats and echoes for sound—and considers the importance of understanding wave behaviour.