Ocean and light waves represent types of transverse waves impacting their medium perpendicular to their direction of travel. Ocean waves travel on the surface of water, forcing the water down along their path. Light waves travel across the electromagnetic spectrum, at right angles to vibrating electrical and magnetic fields.
Sound waves exemplify longitudinal waves, impacting their medium back and forth in the same direction as the wave. Transverse and longitudinal waves are mechanical waves and share common properties.
Wave paths reflect the forward movement of energy, not matter. The medium only moves up and down in transverse waves or back and forth in longitudinal waves. The energy expresses itself in crests and troughs, with wavelength defining the space between any two crests or troughs. Amplitude is the height of a crest or the depth of a trough from the path of the wave. Frequency is the number of crests that pass a single point per second.
Waves can be stationary when they are the result of two waves traveling in opposite directions in an enclosed space. Sound reflected as the vibration of a violin string is an example of a stationary wave. Gravity waves are a particular instance of transverse waves that travel through space and time powered by gravity. The impacts of gravity waves have been detected by inference.
Wave physics has many applications, including astrophysics, boating safety, radio transmissions, laser technology and the design of medical scanning tools.