Task 3

Materials and tools for a working group:

2 same flashlights, small object (e.g., chess figure)

The task of pupils is to explore how shadow is created and how shadow properties can be changed by changing conditions. The questions are aimed to make their research detailed and to focus the pupils on how the phenomenon happens in different situations. Consequently, they are encouraged to use this knowledge to formulate predictionsfor two specific situations. In the first, their task is to think about how many shadows the object will have if it is in a room with four lights. The task is to make pupils consider not only whether they can have more shadows, but when the shadow of the object is not created. The answer to the question may be different, depending on how the learner can think about the question and how he/she can use previous knowledge. Accordingly, a reasonable justification for the task is expected. For example, a pupil may claim that the object may have 4 shadows, but may have only three shadows if the object is under exactly one of the sources, for example, if it is under the lamp, the shadow is not formed.

The second question examines whether shadows are being created if we light object using two same torcher from opposite sides of the object while it is lighted at the same angle. It is appropriate if the teacher introduces two alternative predictions to the pupils. According to the first prediction, the shadows will not be created, while the teacher will give the children the explanation that if the shadow is behind the object, where the light does not get, but the light there on the other side with a second flashlight, so the shadows will not be created. The second predictionexplains the phenomenon by creating two shadows because we have two sources of light. In this way, the teacher creates (among other things) an example of a person trying to create predictionsbased on previous knowledge and logical reasoning. That is, it does not, but really tries to justify its prediction.

After the predictions are made, the teacher will provide the pupils with two identical torches and the object and pupils will examine whether or not two shadows are created. Pupils find that two shadows are created. The teacher can provide explanations to the pupils. When we shine with two flashlights on the same object, there are places where we are lit by both flashlights (there is two times more light) and there are places where we only flash one flashlight, creating a place where there is less light – shadow.

Consequently, the teacher can guide pupils to know how the shadows behave in the question: How many shadows does a footballer have on a football field when playing under the lights? It is advisable if the teacher guides the pupils to make predictionsfirst and then verifies them through watching a football match or modeling a football field in a four-light shoe box and a player‘s figure. In order to think precisely about the situation and to try to use all of their knowledge to date, the teacher also asks some questions when making predictions, for example: Will the football player still have the same number of shadows when moving around the playground? How many shadows will he have if he digs a corner kick? Will all his shadows be as dark? Etc.