Properties and Types of Light

Light is a form of electromagnetic radiation.
Visible light is the portion of the electromagnetic spectrum that is visible to the human eye.

Speed: Travels at approximately 299,792 kilometers per second in a vacuum.
Wavelength: Distance between successive peaks of a wave; determines color in visible light.
Frequency: Number of waves that pass a point in one second; higher frequency equals shorter wavelength.
Reflection: Light bounces off surfaces.
Refraction: Bending of light as it passes from one medium to another.
Diffraction: Spreading of light waves when they encounter an obstacle or aperture.

Incandescent: Produces light when a material is heated (e.g., traditional light bulbs).
Fluorescent: Uses gas and phosphor to produce light; more energy-efficient.
LED (Light Emitting Diode): Emits light when electrical current passes through; highly efficient and long-lasting.
Laser: Produces highly focused light of a single wavelength; used in various applications from medicine to telecommunications.

Absorption: Light is absorbed by materials, converting to energy (heat).
Transmission: Light passes through a medium (e.g., glass).
Scattering: Light is redirected in various directions, affecting visibility (e.g., blue sky due to Rayleigh scattering).

Excessive exposure to certain light sources (e.g., UV light) can cause damage (skin burns, eye damage).
Proper protection (sunglasses, sunscreen) is important when exposed to intense light sources.

Speed: Travels at about 299,792 km/s in a vacuum.
Wavelength: Distance between wave peaks; determines color in the visible spectrum.
Frequency: Number of waves crossing a point per second; higher frequency correlates with shorter wavelength.
Reflection: Light bounces off surfaces, enabling sight and image formation.
Refraction: Light bends when transitioning between different media, altering its direction.
Diffraction: Spreading of light waves when confronting obstacles or openings.

Natural Light: Originates from natural occurrences, like sunlight and starlight.
Artificial Light: Generated from human-made sources, such as electric bulbs and LEDs.

Incandescent: Light produced through heating a material, exemplified by traditional light bulbs.
Fluorescent: Generates light via gas and a phosphor coating; noted for energy efficiency.
LED (Light Emitting Diode): Produces light through electrical currents, renowned for efficiency and longevity.
Laser: Emits concentrated light at a single wavelength; widely used in fields like medicine and telecommunications.

Color categorization is based on wavelength:
- Red: Longest wavelength (approximately 620-750 nm).
- Violet: Shortest wavelength (around 380-450 nm).

Absorption: Materials absorb light, transforming it into energy (heat).
Transmission: Light moving through a medium, such as glass.
Scattering: Light redirected in multiple directions, impacting visibility; a phenomenon exemplified by the blue sky (Rayleigh scattering).

Photography: Captures images via light-sensitive materials or sensors.
Illumination: Provides light for visibility in diverse environments (homes, streets).
Communication: Utilizes light in fiber optics for rapid data transmission.
Medicine: Employs lasers in surgical procedures and medical diagnostics.

The human eye senses light through two types of photoreceptor cells:
- Rods: Enable vision in low-light conditions but do not detect color.
- Cones: Facilitate color vision and finer detail in well-lit environments.

Prolonged exposure to certain light sources, including UV light, can cause harmful effects like skin burns and eye damage.
Protective measures, such as wearing sunglasses and applying sunscreen, are crucial for safeguarding against intense light exposure.