}

Geometric swirls

2006/05/22 Rementeria Argote, Nagore - Elhuyar Zientziaren Komunikazioa

If we ask ourselves what is the aspect of the center of a whirl that is spinning, surely anyone responds that it is circular. And even if there is time to think, few will change their response. But in nature other geometric structures have also been observed, such as atmospheric swirls, the eye of a hurricane or the swirl of some Saturn clouds.

Now these other geometric structures have been seen in the laboratory. To do this, they place the water rotating in a cylindrical container and observe that, as the speed accelerates, the image that draws the water in the background passes from one structure to another: first appeared a three-pointed star, then a square, then a pentagon, and at a very fast speed the hexagon.

Photo: Thomas Jansson.