Colour and refraction

• The primary colours are red, green, and blue.
• White light contains all visible wavelengths, while monochromatic light only has one specific wavelength.
• Secondary colours can be made by mixing two primary colours together.
• When white light is shone through a prism, it separates into its component colours due to dispersion.
• Colours are produced when white light passes through a prism or dispersing medium such as water droplets in the sky during sunrise/sunset.
• Red light travels more slowly than violet light, causing it to bend more when passing from air into water or glass.
• Dispersion occurs because the speed of light changes as it passes from air into glass or water.
• Violet light travels faster than red light.
• Reflection of light

  1. Angle of incidence

  2. Angle of reflection
• Absorption of light

  Materials absorb particular colors while reflecting others
• The colors that are reflected are the ones we see
• If an object absorbs all wavelengths of visible light it will appear black
• If an object reflects all visible wavelengths it will appear the same color as the light that is illuminating it
• Refraction

  Light bends as it travels from one medium to another
• Light moves a bit more slowly through water than air, which explains why objects in the water sometimes appear to be closer than they actually are
• Prism splitting white light

  Different wavelengths of visible light are slowed down by different degrees, causing the colors to fan out
• Complementary colors

  Colors that combine to make white light
• Our eyes have three kinds of color receptors, each of which is sensitive to red, green, or blue light, which can be stimulated in various combinations
• Subtractive primary colors

  Cyan, magenta, yellow
• When the subtractive primary colors are combined, they subtract all of the colors from white light and the mixture will appear black
• The colour spectrum is the range of colours that can be seen by the human eye.
• Violet light bends most, followed by blue, green, yellow, orange, and red.
• A ray of light travelling from a less dense medium to a denser medium will always bend towards the normal line.
• A ray of light travelling from a more dense medium to a less dense medium will always bend away from the normal line.
• Colours on opposite sides of the spectrum are complementary (e.g., red and cyan).
• Red has the longest wavelength and violet has the shortest wavelength.
• Different coloured lights have different speeds when passing between media with different densities.
• The speed of light is fastest through air and slowest through glass.
• This separation of white light into its component colours is known as dispersion or chromatic aberration.
• Tertiary colours are created when equal amounts of two secondary colours are mixed together.
• When light passes from one transparent substance to another, it bends at an angle called the angle of incidence.
• Light travels faster through denser material than it does through less dense material.
• If the second medium has a higher density than the first, then the angle of incidence will be greater than the angle of refraction.