Absorption - Absorption is when some of the wave's energy is taken away when a wave encounters a medium.
Amplitude - The measure of the displacement of the wave from its rest position. The higher the amplitude of a wave, the higher its energy.
Coherence - Two waves are said to be coherent when they have a constant phase difference between them.
Crest - The crest is the highest point of a wave. The opposite of the crest is the trough.
Diffraction - Diffraction is when a wave remains in the same medium, but bends around an obstacle.
Electromagnetic Waves - Electromagnetic waves are waves that can travel through a vacuum. They do not need a medium. Light is a type of electromagnetic wave.
Frequency - The frequency of a wave is the number of times per second that a wave cycles. The frequency is the inverse of the period.
Intensity - A measurement of the strength of a sound wave that is equal to the power divided by the area.
Interference - Interference is when one wave comes into contact with another wave.
Light wave - A light wave is a special type of electromagnetic wave that has a frequency in the visible spectrum.
Longitudinal - A longitudinal wave is a wave where the disturbance travels in the same direction as the wave. Sound waves are longitudinal.
Mechanical Waves - A mechanical wave is a wave that must travel through some sort of matter called a medium. Mechanical waves cannot travel through a vacuum like outer space.
Medium - The medium is the matter that a wave travels through.
Period - The period of a wave is the time between wave crests. It is the inverse of the frequency.
Polarization - Polarization is when a wave oscillates in one particular direction. Light waves are sometimes polarized by a special polarizing filter.
Reflection - Reflection occurs when a wave bounces off a boundary, changing direction but remaining in the same medium.
Refraction - The change in direction and wavelength when a wave moves from one medium to another.
Refractive Index - The refractive index is a number that describes how light travels through a specific medium. Different mediums have different refractive indexes. The refractive index of a vacuum is defined to be 1.
Resonance - Resonance is the tendency for a system to oscillate with greater amplitude at some frequencies than at others.
Resting position - The resting position is the position the medium would take if there were no wave. It is represented on a graph by a line through the center of the wave.
Sound wave - Sound waves are mechanical waves that are caused by a vibration. Sound waves can be heard by our ears.
Speed - The speed of a wave is a measure of how fast the disturbance of the wave is moving. The speed can be dependent on the type of medium that a wave is moving through.
Standing wave - A standing wave is a wave that remains in a constant position.
Transverse - A transverse wave is a wave where the disturbance moves perpendicular to the direction of the wave.
Wave - A wave is a traveling disturbance that moves through space and matter. Waves transfer energy from one place to another, but not matter.
Wavelength - The wavelength of a wave is the distance between two corresponding points on back-to-back cycles of a wave. For example, between two crests of a wave.
Trough - The trough is the lowest part of the wave. The opposite of the trough is the crest.
