1. Exploring Shadows
Start by investigating light and shade for yourself, using pictures from magazines or photographs. Which parts of the picture stand out because they are directly in the light? Where do you see shade or shadows? Can you work out where the light source is coming from? When do we see a silhouette (the dark outline of an object or person)? Try this out for yourself, perhaps with a colleague.
You are now investigating ‘cause’ and ‘effect’ with regard to light by considering the evidence you have observed and you are thinking scientifically. You might want to try this investigation with some of your pupils.
Case Study 1 shows how it is important for pupils to experience the science they are talking about. In Activity 1, you encourage your pupils to think about effects they observe and to recognise patterns when doing experiments with light.
Case Study 1: Categories of possibility
Busiku was going to read her class a story about a child losing their shadow. First, she planned for them to notice their own shadows more consciously. Outside in the morning sun they traced their shadows on large sheets of paper. The shadows were shaded in, carefully cut and proudly displayed and talked about in the class and at a school assembly.
The popular story of the lost shadow was reread many times. In this story, a child loses their shadow, but finds a way to get it back again. By now, the original shadows were getting a little damaged. ‘Yes! Yes!’ they clamoured when Busiku suggested they repeat the activity. This time she specifically took them out at noon. They, too, were losing their shadows! The pupils were confused and worried. Wisely, Busiku chose deliberately to leave them like that.
Over the next few weeks, the class talked about this experience, relating it to other observations. They slowly built up their understanding of what had happened to their shadows.
Activity 1: Exploring what can be done with light and shadow
- With your class, discuss the creative game played at night using hands to make shadow images on a wall (see Resource 2: Wall shadows). Set them a homework task of inventing images that can be made.
- They should find out what they must do to make (cause) the shadow picture to be bigger or smaller (effect).
- Pupils must come back tomorrow ready to demonstrate what they have found out.
- Set up a way for pupils to demonstrate their wall shadows in the classroom.
- Help them record what they have found out by:
- listing the different images they demonstrate (pupils do drawings to show the shape of their hands);
- writing down the ‘cause and effect’ findings.
- If nobody mentions it, ask them to investigate what causes the effect that some images are blurred while others are clear?
- Finally, use everyday objects (a cup, a comb, scissors, a hammer etc.) to pose problems. The pupils should only see the image and not the object or how it is held. Hold different objects in a range of positions to cast interesting shadows. Ask your pupils to work out what the object is and explain why they think this.