IOP Institute of Physics

# Apparatus

Sunlight and space travel

Activity 5: Light travels in straight lines – quick demonstration

• Powerful torch
• Board duster with chalk on it

Activity 7: Game with sheet

• Large white sheet
• Powerful torch

Activity 8: Day and night

• Inflatable globe – available from websites ~ £3.95 for 30cm diameter
• (A football can be used as a substitute for the globe)
• Powerful torch

Activity 12: Solar Pyramid Website

Activity 16: Seasons:

• Dark umbrella – (black, brown, dark green)
• Bright torch

Slide 20 - consider beams of light (and heat) from the Sun, reaching the surface of the Earth. During the winter a beam, of a fixed cross-section, reaching the surface of the Earth will be spread over a greater area than a similar beam reaching the Earth in the summer. An umbrella is held first with its surface tipped towards the beam of light from the torch and then tipped away. The torch should be the same distance from the umbrella throughout the experiment because it is not emitting a parallel beam of light.

The demonstration could also be used to show that in summer, when the sun is high in the sky, the heat and light is concentrated on the surface - a small bright circle is seen in the demonstration. Then in winter when the Sun is low in the sky, a larger dimmer oval is seen because the heat and light are less concentrated, (less spread out).

Understanding statements such as ‘the energy received per unit cross sectional area of the surface of the Earth’ is difficult for all children. This demonstration and slides 19 and 20 explain why it is colder in winter than in summer. Also the Sun is above the horizon for a shorter time than in summer so the total heat reaching the region is less than in summer. The light travels slightly further through the atmosphere in winter so more heat is absorbed.

Activity 17: Game to explain seasons

For each group of about 4 children:

• Torch
• Piece of card – A4 or larger

You are advised NOT to take a radiant heater into school. It would need a portable appliance test. If one is used, it must have a silica (quartz) sheath over the element and not have a bare element.

Activity 18: Demonstration 1 of phases of the Moon

• Football
• White cloth or white plastic from a bag
• Black bin bag or black cloth

Cover the ball so that it is half white and half black

Activity 18: Demonstration 2 of phases of the Moon

• White or pale coloured football - (if a white ball is not available then paint a ball or cover it with white plastic.)
• Marker pen
• Clear plastic (bag) – cut a circle with diameter = half circumference of ball
• Black plastic bin bag

Use a maker pen to draw a large face on one side of the white ball.

Make a sliding cover:

Use the adhesive tape to stick the black plastic round the edge of the clear plastic circle.

Shape the plastic over the ball and draw the black plastic loosely to keep the cover on the ball. Cut a hole to allow your hand to hold the ball.

Activity 20: Game to explain that apparent size varies with distance

For each group of about 4 children:

• Cardboard tube from a kitchen roll or similar
• Small object about 10cm across - or a child’s fist
• Larger object about 30 cm in across

Activity 21: to explain eclipse of Sun

• Circles of card about 8 cm in diameter – enough for at least 1 between 4

Activity 25: Pluto probe
More details on web e.g. at: