Creating Saturn's...septagon(?) in the laboratory

Creating Saturn's...septagon(?) in the laboratory
Creating Saturn's...septagon(?) in the laboratory This is a top-down view of a laboratory tank in an experiment designed to reproduce the wind conditions near Saturn's north pole. The whole cylindrical tank is 60 centimeters wide. Its lid and base are split into two concentric sections, with the inner circle being 30 centimeters in diameter. The inner and outer circles are rotated at different rates, which sets up an instability at their boundary, producing a standing wave; the number of waves it takes to encircle the "pole" depends on various experimental parameters, including the rotation speed. In this particular case, the wavenumber is 7, producing a septagon -- one more "wave" than the number that surrounds Saturn's pole. Dye has been injected into the tank to make the form of the turbulent flow visible. Eddies are produced outside the wave. Courtesy of Ana Aguiar