media when the force of gravity or buoyancy tries to restore equilibrium. A ripple on a pond is one example. Gravitational waves Gravitational waves also travel through space. The first observation of gravitational waves was announced on 11 February 2016. Gravitational waves are disturbances in the curvature of spacetime, predicted by Einstein's theory of general relativity. See also Index of wave articles Waves in general Parameters Waveforms Electromagnetic waves In fluids Airy wave theory, in fluid dynamics Capillary wave, in fluid dynamics Cnoidal wave, in fluid dynamics Edge wave, a surface gravity wave fixed by refraction against a rigid boundary Faraday wave, a type of wave in liquids Gravity wave, in fluid dynamics Internal wave, a wave within a fluid medium Shock wave, in aerodynamics Sound wave, a wave of sound through a medium such as air or water Tidal wave, a scientifically incorrect name for a tsunami Tollmien–Schlichting wave, in fluid dynamics Wind wave In quantum mechanics In relativity Other specific types of waves Alfvén wave, in plasma physics Atmospheric wave, a periodic disturbance in the fields of atmospheric variables Fir wave, a forest configuration Lamb waves, in solid materials Rayleigh wave, surface acoustic waves that travel on solids Spin wave, in magnetism Spin density wave, in solid materials Trojan wave packet, in particle science Waves in plasmas, in plasma physics Related topics Absorption (electromagnetic radiation) Antenna (radio) Beat (acoustics) Branched flow Cymatics Diffraction Dispersion (water waves) Doppler effect Envelope detector Fourier transform for computing periodicity in evenly spaced data Group velocity Harmonic Huygens–Fresnel principle Index of wave articles Inertial wave Least-squares spectral analysis for computing periodicity in unevenly spaced data List of waves named after people One-Way Wave Equation Phase velocity Photon Polarization (physics) Propagation constant Radio propagation Ray (optics) Reaction–diffusion system Reflection (physics) Refraction Resonance Ripple tank Rogue wave Scattering Shallow water equations Shive wave machine Sound Standing wave Transmission medium Velocity factor Wave equation Wave turbulence Wind wave Wind wave#Formation References Sources . . Crawford jr., Frank S. (1968). Waves (Berkeley Physics Course, Vol. 3), McGraw-Hill, Free online version External links The Feynman Lectures on Physics: Waves Linear and nonlinear waves Science Aid: Wave properties – Concise guide aimed at teens Differential equations Articles containing video clips