1. Is a form of energy

3. Why is light important?  Photosynthesis  Electrical energy  Heat  To live!

4. What else can light do?  It can be converted into other forms of energy  For example:  Solar power – electrical  Heat energy  Chemical energy - photosynthesis

5. No sun No light bulbs No fires or candles

6. Light travels in waves

7. Light travels very fast! The speed of light is 300,000,000 metres per second

8. It takes light from the sun 8 minutes to reach earth The Sun is approximately 93 million miles from Earth!! How long to you think it would take to drive that distance in a car?

9. 106 YEARS!!! Lets presume he drives at 100mph

10. Light travels in straight lines!

11. What examples are there to prove this???

12. How can we prove this?

14. Mandatory Experiment  To show that light travels in straight lines. 1. Take three pieces of cardboard. 2. Place a hole in the centre of each. 3. Place the apparatus as shown in the diagram.

15. Luminous and non-luminous objects  Luminous objects give out the own light  Examples?? Light filamentThe Sun

16. Non – luminous objects  Reflect light!  example??  Your books  Your chair  Your table

17. Now a tricky one  Is a light bulb non - luminous?  http://videos.howstuffworks.com/hsw/62 40-out-of-darkness-reflection-and- luminosity-video.htm

18. COLOUR Imagine you could only see in black and white. What are the possible implications this could have on your life? Would it rule out any careers for you? What dangers could there be?

19. What has colour got to do with light?!

20. 1.Shine a ray of bright white light at a prism, as shown above, and move the prism until colours appear. 2.Draw a diagram to show what your observed. White light is split up into 7 colours ???????

23. The white light splits up into 7 colours called the...

24. Where have you seen this before??  Rainbow  CD  Oil on the ground  The sky??

25. R.O.Y.G.B.I.V  RED  ORANGE  YELLOW  GREEN  BLUE  INDIGO  VIOLET

26. Until now we have used the title ‘splitting white light up’. However this process has a scientific name. The splitting of white light into a spectrum of colours is called DISPERSION. But why does white light get dispersed? Colour : splitting white light up

27. Dispersion Each of the colours [ROYGBIV] has a slightly different waveform - what is different? They each have a different wavelength [ ].

30. Primary Colours of Light

32. REFLECTION

33. What makes a good reflector?? Any example of a really good reflector?

34. What do we notice about reflection?  Light bounces back  Lateral inversion

35. DogManBall BatBikeAnts ParkFinsPink LitterSandyShark

36. To investigate the reflection of light by a PLANE MIRROR

37. Mirror Light Beam ir

39.  http://www.freezeray.com/flashFiles/Refl ection1.htm

40. Uses of Reflection?!

41.  http://www.flickr.c om/photos/abysp here/4568574330/ http://www.flickr.c om/photos/abysp here/4568574330/

42. Periscope!

45. Refraction

46. Refraction is the bending of light when it moves from one medium to another

47. Refraction : Bending light The speed of light waves depends on the material they are travelling through. If the light waves enter a different material [e.g. from glass into air] the speed changes. This causes the light to bend [or refract]. Air = FastestDiamond = slowestGlass = slower Glass

48. Fast and slow  If you were running along a beach and then ran into the water when would you be moving slower, in the water or on the beach? In a similar way as light moves from one medium to another of different density the speed of light changes. Do you think light moves faster or slower in a more dense medium? Light moves slower through a more dense medium.

49. Refraction - at the air-glass boundary

50. To show the refraction of light as it passes from air to glass 1. Pass a ray of light from a ray box into a block of glass on a white sheet of paper. 2. Note the direction of the light rays outside and inside the glass. 3. Make an outline of the block of glass. 4. Trace the ray of light using a pencil. 5. Finish the ray diagram and label. 6. Write up experiment in your lab copy

51. Ray box Glass block Ray of incidence Ray of refraction??

52. Refraction in a Block of Glass Incident Ray Refracted Ray I R Block of Glass

53. Result?  Your ray diagram should show the refraction of light.

54. Refraction in a rectangular block

55. http://teachertube.com/viewVid eo.php?video_id=107400&title= bill_nye_the_science_guy___refr action_2_3

56. APPLICATIONS OF REFRACTION LENSES A LENS IS A PIECE OF TRANSPARENT MATERAIL THAT HAS A LEAST ONE CURVED SURFACE

58. Investigate how light is refracted through these lenses.  Set up apparatus.  Place ray diagram at end of paper and shine light ray through the lens.  Trace the path of refraction on the sheet of paper.  Outline the shape and position of the lens.

59. note!  Use fine three ray slide.

60. (Draw ray diagrams)

63. Uses of a lens