How you can tell the time of day from shadows cast by the sun. The sun is our main source of light. Nuclear reactions at the core of the sun create energy in the form of heat and light. The light reaches us in just eight minutes and the earth depends upon it to grow and survive. The earth moves around the sun and, depending on the time of day, shadows formed by its light will be longer or shorter.

This clip is from:
Primary Focus Science
First broadcast:
22 April 2008

The students could be provided with handouts to create their own sundials and have fun telling the time at different points throughout the day. Students could do this in groups so that they can compare notes at the end.

Alternatively, students could have fun estimating the time without clocks by looking at the position of the sun in the sky. Students will need to face South towards the equator to do this and be aware that the sun rises in the east and sets in the west. Roughly speaking, if the sun is in the middle of the sky then it is 12:00. Using this information, students should be able to make rough guesses about the time based on where the sun is in relation to the eastern or western points on the horizon.