WAVES

Waves are among the most fundamental phenomena in nature. A stone dropped in water creates ripples spreading outward; sound propagates through air; light travels across space; ocean swells cross continents; seismic waves reveal Earth's interior. Unlike oscillating objects that vibrate in place, waves carry disturbances from one location to another, transporting energy without net mass transfer. Waves arise whenever a disturbance in a medium propagates due to elastic restoring forces binding the medium's constituents. The remarkable feature of waves is universality: despite vast differences in media and mechanisms, waves follow universal mathematical laws. Sound waves in air, water waves on ocean surface, seismic waves in rock, and electromagnetic waves in vacuum all obey the same fundamental principles. Understanding waves enables explaining phenomena from music to earthquakes, from tsunamis to radio communication. This chapter develops wave concepts systematically and explores universal wave properties applicable across physical systems.

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