This is a 15 - 20 minute resource that has been used for both KS1 and KS2 children. As long as the enquiry based learning methodology is used the lesson will find its own level. Children of all skills and abilities will be enthused and motivated by this simple to prepare and pleasure to deliver lesson plan.
Materials
¨ Education Harbour Rainbow Glasses
¨ Light Source (a wind up torch).
Procedure
1. Prepare the glasses ready to hand out to the children. Make sure nobody tries them on until you say so.
2. Show the children your wind up torch and ask them if they know what it is and what it does.
3. Affirm that the torch uses energy from you and converts that to electricity and which is then converted to light energy.
4. Wind the torch slowly and ask them what the colour the light is. The answer that you are looking for is ‘yellow’
5. Wind it up as fast as you can and ask what colour the light beam is now. The answer that you are now looking for is ‘white’.
6. This should begin to suggest that there is a relationship between energy and colour.
7. Ask them to name any other forms of yellow or white light.
8. Ask them to decide which is the brightest form of yellow/white light that they can think of. The answer will be ‘the sun’.
9. Explain to the children that white light coming to us from the sun contains all the colours that we see in our day to day lives. Ask what colours can be seen at night when it is dark and the sun is not shining?
10. Ask the children if they can think of any times when the nature shows us that the sunlight is made up lots of different colours? While they are thinking hum the tune to ‘Somewhere over the rainbow’ or play it on the class music system if your humming is not good.
11. Ask if anyone can name all of the colours of a rainbow in the correct order.
12. Red, Orange, Yellow, Green, Blue, Indigo, Violet
13. Explain that this is always the order and that red is the first colour and the one with the most energy (as in red hot) and violet is the lowest energy colour that we can see. Just below violet there is ‘ultra violet’ which is so low in energy that we cannot even see the colour with our naked eyes.
14. There are a few simple ways to remember the order:
- ROY G BIV
- Richard Of York Gave Battle In Vain
15. Point out that Red, Blue and Yellow are called Primary colours and that all other colours can be made my mixing these three.
16. Explain that rainbows happen when droplets of water in a cloud break up the sunlight into the different colours in a process that we call ‘diffraction’.
17. The word, and scientific concept of ‘diffraction’ was introduced to us by Francesco Maria Grimaldi some time around the mid seventeenth century from the Latin word ‘diffringere’ which means ‘break into pieces’.
18. Between 1670 and 1672 Sir Isaac Newton also studied this same effect by looking at the sunlight shining on raindrops on his window.
19. Would you all like to see exactly what Francesco and Sir Isaac saw but without waiting for sunlight to shine on raindrops?
20. All I need is my wind up torch again and all you need is to wear a pair of these Diffraction Glasses that I am going to hand out now.
21. To ensure that they work well for you, do not put them on until I say so.
22. Turn off the classroom lights and, if practical, close the blinds/curtains.
23. Wind up the torch and ask them to put the glasses on.
24. Make sure that they all say ‘ooh’ in harmony.
25. Light up a second torch, a candle or other local light sources and listen for more oohs.
26. Explain that the glasses have a very small grating in the lens that serves to break up the light just as the arch on a raindrop does.
27. Turn the classroom lights back on and the children will see for certain that it was not your special light; the concept of diffraction works with almost any light.
28. Collect up the glasses and summarise.
About 300 years ago, Sir Issac Newton saw a beam of sunlight through a glass prism. He discovered that light is made up of a spectrum of seven distinct visible colours. This spectrum of colours always appears in the same order. You can see this colour spectrum (Red, Orange, Yellow, Green, Blue, Indigo, Violet and all the colors in between) when you look through your Education Harbour Rainbow Diffraction Grating Glasses. There are two colour ranges that are not visible to our eyes in this spectrum: below red is infra-red and above violet is ultra-violet. In a rainbow after a rainstorm this same colour spectrum appears in the same order. Rainbows are created when sunlight passes through rain drops that act as millions of tiny prisms.
The colour of a solid object depends on the colours of light that it reflects. A red object looks red because it reflects red light and absorbs all other colours. A blue object looks blue because it reflects blue light and absorbs all other colours. A white object reflects all colours of light equally and appears white. A black object absorbs all colours and reflects no visible light and appears black. Just like when you colour with too many colours in one area with crayons or markers, all colours are absorbed, none are reflected and it appears black!
Ends:
Other ideas to reinforce learning:
- Newton’s Colour Wheel
- Colour Filters to make things dissapear
- Primary Colours
o The primary colours are red, blue, and yellow. The secondary colours are combinations of the primary colours. For example if you mix blue and red, you get purple; if you mix red and yellow, you get orange, and if you mix yellow and blue, you get green. These are the secondary colours. If you then mix a secondary colour with a primary colour, you will get another set of colours called tertiary colours. You can see what colours they are by using the colour wheel.
Absorb: When light does not bounce off a surface, so that it does not return to our eyes and we cannot see it.
Black: We see black when white light (or all the colours of light) hits a surface and is absorbed, leaving nothing to reflect back into our eyes.
Colour: Different colours are made of different wavelengths vibrating at different speeds. We see a colour when white light hits a surface, and a particular colour is reflected back into our eyes (such as green being reflected off grass), the other colours being absorbed at the same time.
Light Spectrum: An arrangement of light rays according to wavelengths.
Primary Colours: Red, yellow and blue.
Reflect: When light bounces off a surface to return to our eyes so that we can see it.
Secondary Colours: Produced by mixing any two of the three primary colours.
Tertiary Colours: Produced by mixing one primary colour with one secondary colour.
Ultraviolet “Black” Light: A colour we cannot really see. It is at the end of the visible spectrum after violet. It kills bacteria and is the main ingredient in a summer tan.
Visible Spectrum: The part of the light spectrum that we can see. |
