Science Unit6a

• Shadows depend on:

  • The nature of the object (opaque objects cast a shadow)
  • The intensity of the light (bright or dim)
  • The size of the object
  • The shape of the object
  • The distance between the source of light and the object
  • The distance between the object and the place the shadow is cast
• A very dark shadow with no light is called a pitch-black shadow
• People used shadow clocks or sundials to tell the time in the past
• Intensity: An electric light has greater intensity than a lighted match
• A lighter shadow is called a faint shadow
• If your shadow is very short, it is likely to be midday
• Ibn al Haytham, a Muslim physicist from Persia (965-1039 CE), was the first scientist to study and investigate light
• Ibn al Haytham invented the pinhole camera and carried out experiments showing the dispersion of light into seven colors
• Ibn al Haytham's studies included shadows, rainbows, and eclipses