Diffraction grating

HOW

1. Position the device so that the sun illuminates the frosted window. A diffraction grating is located there.
2. Observe the image from the other side of the device.

WHY

A diffraction grating is a transparent plate with a large number of parallel lines that do not transmit
light. Light waves pass through narrow gaps between these lines. There they deflect and continue to spread out in a semicircle. This phenomenon is called diffraction (deflection).

Waves from different gaps overlap and intensify at specific spots. We then speak of the phenomenon of wave interference. These spots vary for different wavelengths and therefore different colour. With diffraction and interference, a spectrum of sunlight can be observed with the colours arranged in reverse order to the prism.