light

• Filter


  Absorbs some wavelengths of white light and lets other coloured light through
• Red filter


  Absorbs all colours except red light
• Magenta filter


  Absorbs all colours except red + blue
• Cyan filter


  Absorbs all colours not green + blue
• Yellow filter


  Absorbs all colours not red & green
• White light is not a colour but a mixture of all the colours of the rainbow
• Black is not a colour. Black means the absence of light
• Dispersion


  The splitting up of white light into its component colours
• Three primary colours (red, green, blue) can be mixed in different amounts to make all colours
• Colours made by mixing the three primary colours


  • Magenta
  • Yellow
  • Cyan
• Black


  Absorbs all colours except red and so is seen as red. Skin absorbs all colours. No colours are reflected and so it appears black
• Colours in the spectrum of white light


  • Red
  • Orange
  • Yellow
  • Green
  • Blue
  • Indigo
  • Violet
• Banana


  Looks yellow because the pigment in the skin of the banana will only reflect yellow light
• Refraction


  When light travels from one medium to another, it bends or refracts
• Light travels at the speed of 300,000,000 m/s but if the light goes into a substance or medium which is optically denser than air, it slows down</b>
• Incident ray


  The ray of light hitting the glass
• Red light travels faster in glass than blue light. Red light doesn't refract as much
• Transparent


  Always allows light to pass through and gives a clear image (window glass)
• Translucent


  Allows light to pass through but doesn't give a clear image
• Opaque


  Does not allow any light to pass through, casts shadows (thick cardboard)
• Non-luminous objects reflect light
• reflection


  the bouncing back of a wave when it hits a surface through which it cannot pass
• when light goes into a prism what happens

  colour is slowed down by a slightly different amount