1. Visible Light Visible light is the light that our eyes can detect.

2. Light is… A type of energy Other types of energy are: Heat, electricity, sound, chemical and … Notes

3. Light is not … The sun A globe A flourescent light These are sources of light!! Notes

4. Light is not.. … necessarily made up of rays This is just the model for light that we use to help us to predict what will happen is certain situations Notes

5. Luminous Objects … …produce light which allows us to see them. They are also called sources of light and can be categorised as: Notes Incandescent sources Fluorescent sources Chemoluminescent sources Bioluminescent sources

6. Incandescent sources…...produce light from fast moving electrons that result from the heating a metal or gas e.g. candles, light bulbs, and the sun Notes

7. Fluorescent sources… …. fire electrons into gases causing the electrons in the gas atoms to jump to higher shells. When the electrons return to their normal shell they give off light. Notes

8. Chemoluminescence A form of energy Notes

9. Chemoluminescence A form of energy Notes

10. Bioluminescence Notes

11. What’s Your Theory? If non Luminous objects don’t produce their own light, why can we see them at all angles irrespective of where the source is? Notes

12. What the scientists say. Virtually all objects have a rough surface when you look at them through a strong microscope. These rough surfaces reflect light at all angles. We call this type of reflection Diffuse Reflection Notes

13. What’s Your Theory? Why do different objects appear to be different colours? Notes

14. What the scientists say. Light rays can have different energies and our eyes can detect the rays that have energies in the visible spectrum range. Notes Note !! infrared is shown as black High EndLow End

16. White is not in the spectrum! There is no such thing as white light. White light is a result of all the colours of the rainbow being put together. Light globes, fluorescent lights and the sun all appear to give us white light which actually means that they are producing all the colours of the rainbow mixed together. Notes

17. Proof 1: Prism Notes

18. Proof 2: Rainbow Notes

19. Proof 3: Newton’s Colour Wheel Notes

20. Why do objects appear coloured? Coloured objects are usually non luminous so they do not give off coloured light. Instead they absorb some colours and reflect others. So a red object reflects red and absorbs the other colours. Filters do the same thing e.g. a green filter absorbs all the colours except green. Notes

21. Colour Subtraction http://mysite.verizon.net/vzeoacw1/colorsub.html Notes Cyan, Yellow and Magenta are known as the Artists Primary Colours

22. What’s Your Theory? How do the old TV screens give us coloured pictures? Notes

23. What the technicians say. Notes

24. What the technicians say. Notes

25. Colour Addition http://mysite.verizon.net/vzeoacw1/coloradd.html Notes Green, Blue and Red are known as the Scientists Primary Colours

26. Comparing The Two Systems Notes

27. What’s Your Theory? Why do we see rainbows? Where do we see rainbows? Notes

28. What the scientists say. Notes

29. Where do we see rainbows? Notes