Goal: Creating an Imitation Rainbow Spectrum

Things we need:

• Food colouring (RED, YELLOW, BLUE)
• Plastic Container with lid (we used preformed soda bottles)
• Rain Saver Crystals (100g)
• Spoons
• 1 Litre water jugs x3

Procedure:

Step 1
Fill each of the three jugs with water and add food colouring so you have one jug of each colour RED, YELLOW, BLUE. A good strong colour will give better results.

Step 2
Add 3 or 4 tea spoons of Rain Saver Crystal to each jug and stir. Let it stand until the crystals have soaked up all the water and food colouring.

Step 3
Start adding the mixture to the plastic container/ preform starting with RED, YELLOW, BLUE and then RED again. Make sure you have an even about of each layer. Make sure layers are packed tight and then close the lid. Extension: Experiment with different combinations and what the possible results will be.

Step 4
Observe your creations for the next 24/48 hours as the colours start to bleed and all the colours of the rainbow are formed. The end product should look like the example below.

RED, ORANGE, YELLOW, GREEN, BLUE, INDIGO, VIOLET
(Roy G. Biv)

click picture for larger version

? Question ?

If I was to stir a rainbow in my mixing bowl it would turn WHITE. 
If I was to mix all the primary colours together it would turn BROWN.

WHY ?

What did Sir Isaac Newton do?
He first took the white light apart and then he put it back together again.

The most common example of a spectrum is the rainbow created in nature. The rainbow is caused by sunshine (white light) shining on water droplets that are in the air just after a summer shower. Thousands of these water droplets break up the light, just like Sir Isaac Newton’s prism. Can you make a rainbow? Of course! Make your own rainbow by turning on the garden hose, which has a nozzle that will make a fine mist, or spray. Make sure the sunlight is coming over your shoulder. You have made a rainbow.

If light is white and all we see is light why do things appear different colours?
Objects absorb some of the colours in the white light and then reflects the rest. The colours that are reflected provide the colour of a specific object. Think about these three basic colours (Red, Blue, Green), if an object absorbs green but reflects blue and red then the object will be purple. The mix of blue and red light gives us purple.

Did you know?
The computer screen you are looking at now can only produce three colours – Red, Blue and Green. So how do we see white on the screen? It follows Newton’s experiments on light and puts the three colours all together to create white.

EXPERIMENT TO TRY

Colour Wheel

1. Print out this template (you may need a PDF reader like the one from Adobe).
2. Cut out the discs and then put a toothpick, or pencil, through the centre. You may need to fix the disc with a bit of sticky tape.
3. Spin the wheel and have a look at the colours that are created. Look at the outer ring of the first disc shown above and the colour should disappear.
4. Repeat with the other patterns and colours.

Note: You may need to stick the paper on to cardboard if your paper is too thin.

Bring your complete wheel to school and receive some Rees Dollars for your effort.

Fun Facts about Light

We do not know of anything in our universe that travels faster than light. The sunlight we see today left the sun 93 million miles away to reach us about 10 minutes later. Light from stars farther away may have taken billions of years to reach our eyes. How many times can light travel around the world while you are saying your name? ……………..more than four times.