Lecture on Light and Luminescence

A collection of flashcards covering key terms and definitions related to light, luminescence, and their properties.

Fluorescence

Produced by absorbing energy of one wavelength and immediately emitting energy of a different wavelength.

Incandescence

Light from a heated body.

Chemiluminescence

Light produced from a chemical reaction without a rise in temperature.

Light

Visible form of energy consisting of electromagnetic waves.

Bioluminescence

Light produced and emitted by living organisms.

LED (Light Emitting Diode)

Light created from electric current passing through a semiconductor.

Opaque

A material that absorbs all incident light, transmitting none.

Electro Discharge

Light produced by phenomena such as lightning or neon signs.

Phosphorescence

Light produced when energy is absorbed and emitted over a long period of time.

Ray model of light

Light waves travel in straight lines from a source.

Transparent

A material that transmits most or all incident light.

Tribo luminescence

Light produced when certain crystals are rubbed together.

Wavelength

The distance between successive crests of a wave, often associated with color in light.

Electromagnetic waves

Waves composed of oscillating electric and magnetic fields, which include light.

Quantum theory of light

The theory that light has particle-like properties as well as wave-like properties.

Spectroscopy

The study of the interaction between light and matter.

Polarization

The orientation of the oscillations of light waves.

Diffraction

The bending of light waves around obstacles or through openings.

Refraction

The bending of light waves as they pass from one medium to another.

Photons

Elementary particles of light, considered to be the quantum of electromagnetic radiation.

Visible spectrum

The range of wavelengths of light that can be detected by the human eye.

Infrared light

Light with wavelengths longer than visible light, typically felt as heat.

Ultraviolet light

Light with wavelengths shorter than visible light, which can cause sunburn.

Lumens

A measure of the total quantity of visible light emitted by a source.

Candela

The SI unit of luminous intensity in a given direction.

Brightness

The perception of the intensity of light by the human eye.

Color temperature

A characteristic of visible light that defines the warmth or coolness of the light.

Luminous flux

The measure of the perceived power of light.

Reflectance

The ratio of light reflected from a surface to the amount of light incident upon it.

Transmittance

The fraction of incident light that passes through a material.

Scattering

The process of light being forced to deviate from a straight line.

Light pollution

The excessive or obtrusive artificial light that brightens the night sky.