A plane wave is classified as a transverse wave if the field disturbance at each point is described by a vector perpendicular to the direction of propagation (also the direction of energy transfer) or longitudinal wave if those vectors are aligned with the propagation direction. In linear media, complicated waves can generally be decomposed as the sum of many sinusoidal plane waves having different directions of propagation and/or different frequencies. Mathematically, the simplest wave is a sinusoidal plane wave in which at any point the field experiences simple harmonic motion at one frequency. However, waves with infinite domain, that extend over the whole space, are commonly studied in mathematics, and are very valuable tools for understanding physical waves in finite domains.Ī plane wave is an important mathematical idealization where the disturbance is identical along any (infinite) plane normal to a specific direction of travel. For example, the seismic waves generated by earthquakes are significant only in the interior and surface of the planet, so they can be ignored outside it. Ī physical wave field is almost always confined to some finite region of space, called its domain. On the other hand, some waves have envelopes which do not move at all such as standing waves (which are fundamental to music) and hydraulic jumps.Įxample of biological waves expanding over the brain cortex, an example of spreading depolarizations. In mathematics and electronics waves are studied as signals. Mechanical and electromagnetic waves transfer energy, momentum, and information, but they do not transfer particles in the medium. Other types of waves include gravitational waves, which are disturbances in spacetime that propagate according to general relativity heat diffusion waves plasma waves that combine mechanical deformations and electromagnetic fields reaction–diffusion waves, such as in the Belousov–Zhabotinsky reaction and many more. Electromagnetic, as determined by their frequencies (or wavelengths), have more specific designations including radio waves, infrared radiation, terahertz waves, visible light, ultraviolet radiation, X-rays and gamma rays. Electromagnetic waves can travel through a vacuum and through some dielectric media (at wavelengths where they are considered transparent). In an electromagnetic wave (such as light), coupling between the electric and magnetic fields sustains propagation of waves involving these fields according to Maxwell's equations.

Other examples of mechanical waves are seismic waves, gravity waves, surface waves and string vibrations. For example, sound waves are variations of the local pressure and particle motion that propagate through the medium. A mechanical wave is a local deformation (strain) in some physical medium that propagates from particle to particle by creating local stresses that cause strain in neighboring particles too. In a mechanical wave, stress and strain fields oscillate about a mechanical equilibrium. There are two types of waves that are most commonly studied in classical physics: mechanical waves and electromagnetic waves. Waves are often described by a wave equation (standing wave field of two opposite waves) or a one-way wave equation for single wave propagation in a defined direction. In a standing wave, the amplitude of vibration has nulls at some positions where the wave amplitude appears smaller or even zero. When the entire waveform moves in one direction, it is said to be a traveling wave by contrast, a pair of superimposed periodic waves traveling in opposite directions makes a standing wave. Periodic waves oscillate repeatedly about an equilibrium (resting) value at some frequency. In physics, mathematics, engineering, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Surface waves in water showing water ripples For other uses, see Wave (disambiguation). For waves on seas and lakes, see Wind wave. This article is about waves in the scientific sense.

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