Sources of Light

Study Notes

Sun: The primary source of light on Earth, accounting for approximately 99% of the light we receive.
Moon: Reflects the sun's light, providing illumination at night.
Stars: Distant celestial bodies that emit light, visible on a clear night sky.

Incandescent bulbs: Produce light by heating a filament until it glows, using electricity.
Fluorescent lamps: Use electricity to excite a gas, producing ultraviolet light that is converted to visible light by a phosphor coating.
LEDs (Light Emitting Diodes): Semiconductors that release energy as light when an electric current passes through them.
Lasers: Concentrated beams of light produced by stimulating atoms or molecules to release photons.

Bioluminescence: The production and emission of light by living organisms, such as fireflies, glowworms, and certain types of bacteria.
Chemiluminescence: The production of light through chemical reactions, such as in glow sticks or fireworks.
Electroluminescence: The production of light by passing an electric current through a material, such as in certain types of displays.

The Sun is the primary source of light on Earth, accounting for approximately 99% of the light we receive.
The Moon reflects the Sun's light, providing illumination at night, making it a secondary source of natural light.
Stars are distant celestial bodies that emit light, visible on a clear night sky, making them a source of natural light.

Incandescent bulbs produce light by heating a filament until it glows, using electricity as the energy source.
Fluorescent lamps use electricity to excite a gas, producing ultraviolet light that is converted to visible light by a phosphor coating.
LEDs (Light Emitting Diodes) are semiconductors that release energy as light when an electric current passes through them, making them an efficient source of artificial light.
Lasers produce concentrated beams of light by stimulating atoms or molecules to release photons, making them a unique source of artificial light.

Bioluminescence is the production and emission of light by living organisms, such as fireflies, glowworms, and certain types of bacteria, which use this process to communicate or attract prey.
Chemiluminescence is the production of light through chemical reactions, such as in glow sticks or fireworks, which use a chemical reaction to produce light.
Electroluminescence is the production of light by passing an electric current through a material, such as in certain types of displays, which use this process to produce light.