Colored Shadows
COLORED SHADOWS (NOT ALL SHADOWS ARE BLACK)
MATERIALS:
white surface
red, green and water colored cellophane
3 flashlights
any solid object
Results:
When a red light, a blue light, and a green light are all shining on the screen, the screen looks white .
With these three lights you can make shadows of seven different colors: blue, red, green, black, cyan (blue-green), magenta (a mixture of blue and red), and yellow (a mixture of red and green). If you block two of the three lights, you get a shadow of the third color: Block the red and green lights, and you get a blue shadow. If you block all three lights, you get a black shadow. And if you block one of the three lights, you get a shadow whose color is a mixture of the two other colors. If the blue and green mix, they make
cyan; red and blue make magenta; red and green make yellow.
DISCUSSION:
The three primary colours in additive colour mixing are red, green and blue. These colours consist of light that is the particular colour’s wavelength. When the three colours are mixed together, they combine (or add up) to make white light.However, if you only mix two of the colours you will get the complementary colour to the light that was removed.
MATERIALS:
white surface
red, green and water colored cellophane
3 flashlights
any solid object
Results:
When a red light, a blue light, and a green light are all shining on the screen, the screen looks white .
With these three lights you can make shadows of seven different colors: blue, red, green, black, cyan (blue-green), magenta (a mixture of blue and red), and yellow (a mixture of red and green). If you block two of the three lights, you get a shadow of the third color: Block the red and green lights, and you get a blue shadow. If you block all three lights, you get a black shadow. And if you block one of the three lights, you get a shadow whose color is a mixture of the two other colors. If the blue and green mix, they make
cyan; red and blue make magenta; red and green make yellow.
DISCUSSION:
The three primary colours in additive colour mixing are red, green and blue. These colours consist of light that is the particular colour’s wavelength. When the three colours are mixed together, they combine (or add up) to make white light.However, if you only mix two of the colours you will get the complementary colour to the light that was removed.
- Red and green make yellow (the complement of blue)
- Green and blue make cyan (the complement of red)
- Blue and red make magenta (the complement of green).
Sources: https://www.questacon.edu.au/visiting/galleries/wonderworks/exhibits/coloured-shadows
http://www.exploratorium.edu/snacks/colored_shadows/
http://www.exploratorium.edu/snacks/colored_shadows/