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. Casting the net even wider, there are mechanical waves, quantum wave phenomena, and the now clearly detected gravitational waves. Look closer and deeper and more kinds of waves appear, down to the most fundamental level of reality. This Very Short Introduction looks at all the main kinds of wave, their sources, effects, and uses. Mike Goldsmith 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. All waves, however different, share many of the same features, and, as Goldsmith shows, for all their complexities many of their behaviours are fundamentally simple. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable.