We continue our exploration of light this week with some fun colour mixing.
The background Light is a kind of energy called "electromagnetic (EM) radiation". This kind of radiation is not harmful, except for an occasional sunburn. There are other kinds of EM radiation too (radio waves, microwaves, x-rays andmore), but light is the part we can see, the part that makes the rainbow.
What you need Some cardboard, three small bits of cellophane: red, blue and yellow, a glue stick, compass and some scissors.
The experiment 1. Cut out a rectangular piece of cardboard measuring 6cm x 21cm. 2. Fold the cardboard into three equal parts. 3. Carefully cut out three circles with approximately 3cm diameter, that line up perfectly on the card when folded. 4. Stick a square piece of coloured cellophane over each circle. Use - red, yellow and blue. Put the blue in the middle and the yellow and red on each side. 5. Hold the cardboard up to the light and look through each window one at a time. Fold the red window on to the blue window. What colour do you see? Fold the yellow window on to the blue window. What colour do you see? Fold the red window on to the yellow window. What colour do you see? Fold all three sections on top of each other. What colour do you see? Can you explain what's going on?
What's happening? Light is made up of wavelengths of light, and each wavelength is a particular colour. The colour we see is a result of which wavelengths are reflected back to our eyes.
The cellophane is acting as a filter, only allowing certain wavelengths through. Yellow, red and blue are the three primary colours. Mixing them gives us secondary colours.
The House of Science Tauranga is a charitable trust which exists to connect and resource the local science community in order to celebrate the power and potential of science.
