Sources of Light

Natural Sources of Light

• 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.

Artificial Sources of Light

• 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.

Other Sources of Light

• 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.

Natural Sources of Light

• 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.

Artificial Sources of 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.

Other Sources of 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.