You will need
- 1 Candle or tea light
- 1 Large bird’s feather
- Fire-proof surface, for example a ceramic plate
What to do
- Light the candle.
- Stand about 1 metre away from the candle.
- Hold the large bird’s feather in front of one eye and watch the candle through the feather. Make sure you look through one of the white or gray coloured parts of the feather.
- If you have positioned the feather correctly, the flame will appear to be multiplied in an X-shaped arrangement. You may have to shift the feather around a bit to find the best position to peak through and observe this.
The X-shaped pattern of the flame is produced when the light passes through the fine vanes and barbs of the feather. The light is bent and changes directions as it passes through them. This bending of light is called “refraction”. The flame appears many times because your eye is looking through several slits at the same time.
You can watch a video of this experiment here: