acoustic Of or relating to sound.
amplitude The maximum displacement of a point on a wave from its rest position.
aperture The opening of a lens, such as that of a camera or the eye.
decibel A measurement of the intensity of sound.
diffraction The apparent bending of waves around small obstacles and the spreading out of waves past small openings.
Doppler effect A change in the frequency of sound or light waves due to a change in the position of the source or destination of the wave.
electromagnetism A fundamental physical force that is responsible for interactions between charged particles.
frequency Number of oscillations per second of a wave.
harmonic A wave with a frequency that is a multiple of that of another wave.
interference The meeting of two waves, causing changes in wave amplitude.
laser A beam of concentrated electromagnetic radiation.
light Electromagnetic radiation that is visible to the human eye.
linear Of or relating to a straight line.
medium The substance through which a wave travels.
microwave Electromagnetic radiation with a wavelength between 1 millimetre and 1 metre.
optics The scientific study of light.
perpendicular Two lines or planes (or a line and a plane) are considered perpendicular (or orthogonal) to each other if they are at right angles to each other.
pitch The frequency of a sound relative to other sounds.
polarization A property of electromagnetic radiation in which the electric field is confined to a specific direction or rotates about the direction of travel.
radiation The emission of energy.
reflection The act of a wave bouncing off a surface in a linear direction.
refraction Change in a wave’s direction caused by its passage through a different medium and the resultant change in the wave’s velocity.
sonic boom The sound made when a shockwave—created from an object going from supersonic to subsonic speed—reaches the ground.
sound Longitudinal waves of compressions and rarefactions that propagate through an elastic medium.
superposition The addition of two waves.
wave An oscillating pattern in which energy travels.
wavelength The distance between crests of a wave.