Physics- Diffraction and Interference

The ability of a wave to bend around a barrier.

Diffraction

The theory that tells us that each point on an advancing wavefront can be thought of as a source of secondary

circular wavefronts.

The relative motion between two waves propagating along the same path (or two points on the same wave).

Phase difference

Two waves (or two points on a wave) that undergo the same motion over time.

In phase

Two waves (or points on a wave) that undergo the opposite motion over time.

Out of phase

The resultant pulse is the sum of the individual pulses.

Superposition

The resultant wave is the sum of the individual waves.

Interference

The amplitude of the resultant wave is larger than the amplitude of either individual wave.

Constructive interference

The amplitude of the resultant wave is less than the

amplitude of either individual wave.

Destructive interference

The bright region where the light has travelled an equal distance.

Central maxima

An artificial material that splits light according to its

wavelength.

Diffraction grating

The specific wavelengths of light emitted or absorbed by an element.

Spectrum

The number of lines per metre on a diffraction grating.

Line density

A point where two waves interfere destructively

and

particles experience no displacement.

Node

A wave of short duration causing a single vibration of

particles.

Wave pulse

A point where two waves interfere constructively

and particles experience maximum oscillation.

The science of the specific absorption or emission of

light by certain elements.

Spectrosopy