As an analytical – and technically schooled – artistPaul van Twist is strongly interested in how and why things work. With this clockhe wants to show the beauty of a well-known physical phenomenon, the ‘Moiré effect’.

What is Moiré effect? It is the visual effect that occurs when two regular patterns with slightly different frequencies are superimposed (“interfere”,in technical jargon) in an image: suddenly new patterns come up, in new directions and with other frequencies.One way to trigger the effect is to have a pattern interfering with a rotated copy of itself. Increasing or decreasing the rotation angle radically changes the resultingMoiré pattern.

In the clock the artist uses two lines, the simplest pattern possible. Whenthey interfere with two other lines, slightly rotated,four white dots light up at the intersection points. The four dots move towards or from each other when the rotation angle changes. Voilà, Moiré in its purest form.