Light

• Light


  A form of energy that is essential to every living being, travels in a straight line called rays
• Reflection of light


  Some of the light is reflected, others are transmitted or absorbed
• Reflection


  The behavior of light to bounce as it strikes a surface, enabling us to see images being reflected from a surface
• Law of Reflection


  The angle of reflection is equal to the angle of incidence
• Normal line (N)


  An imaginary line drawn perpendicularly from the point of incidence on the surface or mirror
• Reflected ray


  A ray that leaves the surface of the mirror
• Angle of reflection


  The distance between the reflected ray and the normal line (N)
• Incident ray


  A ray of light that is pointing towards and striking a surface
• Drawing ray diagrams


  Steps to help remember how to draw a light ray reflection diagram
• Specular reflection


  Reflection on smooth surface that bounces light in one direction creating a clear and vivid reflection of the image
• Diffuse reflection


  Reflection on rough surface that reflects light in various directions due to the uneven orientation on the surface, resulting in a hazy or unclear image of the object
• Light plays a role in the interesting processes in nature, exhibiting wave or particle nature when entering the atmosphere
• Phenomena of light

  • Reflection
  • Transmission
  • Absorption
  • Refraction
• Plane mirror


  A smooth reflecting surface
• Spherical mirror


  A mirror with a curved reflecting surface
• Convex mirror


  A spherical mirror that bulges outward, usually showing things the right way up and smaller
• Concave mirror


  A spherical mirror that is hallowed inwards, with the appearance of the image depending on how close the object is to it
• Opaque


  Some of the frequency of the visible light is absorbed, while others are reflected
• Transparent


  Some of the frequencies of light are absorbed while allowing some to pass through
• Selective reflection and selective transmission


  Tells the color of the object whether it is opaque or transparent
• Visible light (Natural sunlight)


  Composed of the complete range of frequencies
• Artificial light


  Sometimes have a limited range of frequencies, affecting what the object can absorbed or reflect
• Refraction


  The bending of light as it passes through mediums of varying density, due to light speeding up or slowing down
• Optical illusions from refraction

  • Mirage
  • Rainbow
  • Supernumeraries
  • Halo
  • Sundog or a mock sun
• Rainbow


  A mosaic of light sent to you by plenty of raindrops in a seemingly concert-like synchrony
• Formation of rainbow

  1. Light enters a water droplet

  2. Light is refracted

  3. Visible light is dispersed into spectrum of colors

  4. Light reaches the back of the water droplet at a certain angle

  5. Total internal reflection occurs
• Supernumeraries


  • Thin, pastel colored bands or fringes appearing below the primary rainbow adjacent to the violet band
  • Caused by interference of light
• Halo


  Ring of light around the sun or moon
• Formation of halo


  1. Light refracts from hexagonal ice crystals present in cirrus clouds

  2. Ice crystals act like prism with a cross-section of an equilateral triangle
• Sundog or a mock sun


  • White or colored patches of light to one or both sides of the sun
  • Also known as parhelia which means with the sun
  • Typically appears when the sun is low like sunrise and sunset
• Mirage -Is a natural optical illusion that creates illusion of water that results from the bending of light because of the gradient in the air temperature.