As a flapping object moves through a fluid, many patterns of vortices can form in its wake. The familiar von Karman vortex street, so often seen in clouds or behind cylinders, is only the beginning. In the photo above, a symmetric foil flaps in a vertical soap film; as the amplitude and frequency of the oscillation varies, the wake patterns it produces change dramatically. From left to right, a) a von Karman wake; b) an inverted von Karman wake; c) a 2P wake, in which two vortex pairs are shed with each cycle; d) a 2P+2S wake, in which two vortex pairs and two single vortices are shed per cycle; e) a 4P wake; and f) a 4P+2S wake. See some of these flows in action in these videos. (Photo credit: T. Schnipper et al.)
(vía proofmathisbeautiful)
![jessicafurseth:
Radical idealist, technology futurist, renaissance man, artist and dreamer: My piece on the Buckminster Fuller exhibition at the San Francisco Museum of Modern Art, The Utopian Impulse, is in Whitehot Magazine.
“If humanity does not opt for integrity we are through completely. It is absolutely touch and go. Each one of us could make the difference.” [BF]](http://25.media.tumblr.com/tumblr_m669elBvhX1qbeqkxo1_500.jpg)
