A candle light experiment

Experiment 1:

Attention - Safety instruction:
An experiment with fire is dangerous! Work carefully! Watch out to not burn yourself. Only do this experiment while an adult is watching you and on a fireproof surface. Keep a bowl with water at your side, in case you need to extinguish the fire.

For the experiment you will need:

• 2 equal candles
• 1 lighter or matches
• 1 piece of string
• 1 object to create a shadow (book, toy and so on)
• 1 pencil
• 1 bowl with water

Dim the lights in your room!

Set up the experiment as shown in the picture below.

With your pencil, mark the left and the right edge of the shadow..
Blow out the candle and arrange the string along the mark of the object to the wick of the candle.

What can you say about that?

a) The string on the edge of the shadow follows a straight line between the object and the candle because light always follows a straight line.

b) The string on the edge of the shadow follows a cricket line between the object and the candle because the light is deviated into different directions when it hits the object.