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 ph...