Science Realted facts on LIGHT for Primary School 5th/6th Class

1. Light Seán Finn Department of Education UCC

2. Light sources . All of these objects can be seen in the dark because they let out their own light-they are luminous

5. Light travels from a source When it is ABSOLUTELY DARK you cannot see anything at all … but you cannot see it There might be something HERE …

6. Light travels from a source … bounces off it and travels to your EYE … … and NOW you can see it But in the daylight RAYS OF LIGHT from the SUN travel to this object…

7. Light travels from a source There are actually many RAYS OF LIGHT bouncing off the object but the diagrams become too complicated if you put them all in

9. Do all substances allow light to pass through them? Light will not pass through substances like aluminium foil. Light will pass easily through substances like glass Some light will pass through certain substances

10. Opaque materials do not allow light to pass through them.

11. Transparent materials Light will pass very easily through some materials cling film glass window plastic bottle They are said to be TRANSPARENT

12. Translucent materials You cannot SEE through a sheet of greaseproof paper like you can see through glass But if you shine a torch behind the greaseproof paper you can see the light but NOT exactly what the torch looks like

13. De sign and make a model glasshouse using a plastic bottle that will allow light to pass through A cloche Place thermometer in bottle next to light. Note that the temperature of the air in the bottle increases.

14. Investigation: Light travels in straight lines. A B C

15. How light travels … you can see the view out of the other end If you look through a long cardboard tube…

16. How light travels … you cannot see anything out of the other end If you bend the cardboard tube and then look through it…

17. How light travels This is because light travels in STRAIGHT LINES The light CANNOT go any further In this tube there is a straight line from one end to the other In this tube there is only a straight line UP TO HERE

18. How shadows are formed There many of rays of light travelling in STRAIGHT LINES from the torch Some travel PAST the ornament…. … but others “ BUMP INTO ” the ornament and cannot travel any further

19. Formation of shadows torch the OBJECT is blocking the light here Light from the torch travelling in a straight line CANNOT get behind the OBJECT OBJECT SHADOW on wall

20. Size of shadows If light was able to travel in CURVES then we would not get SHADOWS BUT LIGHT ONLY TRAVELS IN STRAIGHT LINES

21. Size of shadows As the toy is moved towards the wall the shadow gets smaller shadow getting smaller

22. Size of shadows shadow getting smaller

23. Size of shadows shadow getting smaller

24. Size of shadows shadow getting smaller

25. Size of shadows LARGE SHADOW when the toy is close to the light SMALLER SHADOW when the toy is further from the light TINY SHADOW when the toy is a long way from the light

26. Formation of shadows

27. Shadow puppets By using a mixture of opaque , translucent and transparent materials you can create shapes to produce shadow puppets Here a simple cardboard shape ( opaque ) has holes made in it ( transparent ) to provide eyes and a mouth

28. Shadow puppets This is a picture of a very complicated shadow puppet It is made from opaque wire and transparent materials that are also coloured giving the shadow produced a very colourful appearance

29. Shadows from the sun Here you can see shadows formed outside by the SUN Notice that the shadows are different sizes at different times of the day SHORT , VERY DARK shadow LONG , LIGHTER shadow

30. Shadows from the sun To see how shadows change during the day stand in a FIXED position and then get someone to draw round your shadow using chalk or water-based paint A few hours later stand in EXACTLY the same place and again get some one to draw around your shadow

31. Shadows from the sun This will show you how much shadows change over a few hours To see how shadows change during the day stand in a FIXED position and then get someone to draw round your shadow using chalk or water-based paint A few hours later stand in EXACTLY the same place and again get some one to draw around your shadow

32. Measuring shadows

33. Measuring the length of shadows On a SUNNY day set up a stick on a clear piece of ground Using a ruler CAREFULLY measure the length of the shadow Notice what time it is and then record your result in a table like this

34. Table of results EVERY HOUR go back to the stick and again measure the length of the shadow 4.00 pm 3.00 pm 2.00 pm 1.00 pm 12.00 noon 11.00 am 10.00 am 47 cm 9.00 am Length of shadow Time

35. Size of shadows 10.00 am 12.00 noon 2.00 pm 4.00 pm

36. Table of results These results can then be put into a BAR CHART to help you see a PATTERN in your results 49 cm 4.00 pm 45 cm 3.00 pm 42 cm 2.00 pm 35 cm 1.00 pm 22 cm 12.00 noon 37 cm 11.00 am 43 cm 10.00 am 47 cm 9.00 am Length of shadow Time

37. Shadows during the day The bar chart shows that the shadow is shortest at 12 noon

38. Light and dark This is a ray of light shining from a torch Put a comb in front of the torch The comb lets light through the gaps, but stops it passing through the prongs The light is broken up into dark and light stripes

39. Day and night

40. The Earth moves, the Sun stays still This is the Sun This is the EARTH looking down on the Arctic These are the rays from the SUN lighting up the EARTH This is the half of the Earth that light from the Sun reaches - DAY This is the half that light from the Sun does NOT reach - NIGHT

41. The sun gives us heat and light without which we could not live

42. Light is a form of energy

43. Experiment: To make a solar panel Perspex sheet Water Thermometer

44. Light is made up of seven colors. -The spectrum

45. Making a spectrum

46. The rainbow.

47. Making a spectrum

48. Making a spectrum

49. Mixing of light

53. The periscope Two mirrors parallel to each other at 45 0

54. Making a periscope

55. Curved mirrors

56. Concave mirror Concave mirors can produce images that are right way up or upside down also larger or smaller. If you place your face close to the mirror your image will by magnified and right way up. Use: Shaving and make-up mirrors

59. Refraction

61. Why does refraction occur?

62. Refraction

63. To investigate refration in a liquid

65. Lenses

66. E xplore how objects may be magnified using simple lens or magnifier

67. Lenses opperate due to refraction

71. The telescope

72. D esign and make model telescopes Tubing Plastic wrap

73. A ppreciate the importance of sight The iris controlls the amount of light entering the eye Bright Dark

74. Structure of the eye The lense of the eye focuses light onto the retina which is carried to the brain via the optic nerve

76. Why the Moon seems to change The MOON looks different depending on where it is in relation to the SUN From the Earth you cannot see any light hitting the Moon in this position New Moon This is what the Moon looks like from Earth

77. Why the Moon seems to change Waxing crescent This is what the Moon looks like from Earth

78. Why the Moon seems to change Last quarter This is what the Moon looks like from Earth

79. Why the Moon seems to change Waxing gibbous This is what the Moon looks like from Earth

80. Why the Moon seems to change Full Moon This is what the Moon looks like from Earth

81. Why the Moon seems to change Waning gibbous This is what the Moon looks like from Earth

82. Why the Moon seems to change Waning crescent This is what the Moon looks like from Earth

83. To demonstrate why the shape of the Moon changes

84. Solar Eclipse

85. Lunar Eclipse

86. It is VERY DANGEROUS to look DIRECTLY at the Sun or at a REFLECTION of the Sun – it could make you BLIND

89. Science Curriculum. Infant and Junior Classes

90. Science Curriculum. First and second classes

91. Science Curriculum. Third and fourth classes

92. Science Curriculum. Fifth and sixth classes