Light Transmission and Interaction

Light Transmission

• Light is made up of individual units called photons, which act as both particles and waves.
• The electromagnetic radiation spectrum includes different forms of light, such as:
  • Microwaves, radio waves, and visible light (middle of the spectrum)
  • Ultraviolet light, x-rays, and gamma rays (high frequencies, high energy)
  • Infrared light, microwaves, and radio waves (low frequencies, low energy)
• When light interacts with objects, it can be:
  • Reflected (bounced off, like a particle)
  • Absorbed (energy taken in by molecules, transformed into thermal energy)
  • Transmitted (passes through objects, like a wave)

Light Absorption and Reflection

• Objects with high reflective properties (e.g., glass, mirrors, shiny surfaces) reflect most of the light that hits them.
• Opaque objects absorb light, converting it to thermal energy.
• Light absorption and reflection are responsible for our perception of color:
  • White light (all frequencies) hits an object, and the reflected color is what we see.

Light Transmission Examples

• Light transmission through transparent materials (e.g., glass, water, plastic) allows light to pass through with little change.
• In the atmosphere, about 30% of sunlight is reflected, while the rest is absorbed or transmitted to the Earth's surface.
• Scattering and refraction occur when light interacts with the atmosphere:
  • Scattering: light hits atoms and is transmitted in all directions (making the sky appear blue)
  • Refraction: light bends as it changes speed through a material (creating rainbows)

Transmission of Waves Definition

• Waves are disturbances in a medium that travel through the medium in an organized way.
• Waves can propagate energy, momentum, and/or information, but not matter.
• Types of waves include:
  • Light waves (photons, particles of light)
  • Sound waves (require a medium, like air or water)
  • Kinetic waves (transfer energy through a medium, like water)

Wave Transmission

• Wave transmission is the movement of a wave through a medium.
• The type of wave and medium can change the wave's energy, wavelength, and frequency.
• Energy loss occurs when waves change medium or type.
• Waves can be scattered or refracted as they transmit through a medium.

Explore how light travels and interacts with objects around us, including how it affects the color of objects and our ability to see.