Moire effect - random versus grid

Topic:
Rotation

Let the grid one run and watch! See the difference with random. Hide the centre (which one can you detect).

Description

Let the grid run and watch. Unexpected things happen as a consequence of the Moire effect. See the difference with random where the centre of rotation is clearer.

Ideas for teaching

- Hide the centre and ask students where the centre is. - Ask students what angle will create different sizes of 'circles'.