Construction de la Tour de Babel.
The Bedford Book of hours (France, ca 1410-1430)British Library Add MS 18850, fol. 15v
Nature is full of remarkable patterns and moments of symmetry. This image shows the wake behind two rotating cylinders. Half of the cylinders are visible at the far left. The flow moves left to right. The cylinders are rotating at the same rate but in opposite directions, clockwise for the cylinder on top and counter-clockwise for the bottom one. At this speed relative to the freestream, there is a beautiful symmetry to the vortices in the wake, but the researchers found that even a slight deviation from this condition quickly destroyed the pattern. The flow is visualized here by introducing tiny hydrogen bubbles via electrolysis. The bubbles are small enough that their buoyancy has no appreciable effect. (Image credit: S. Kumar and B. Gonzalez)
page 402 of “Britain’s birds and their nests” (1910)
Digital painting of a crow!! Eventually I gave up on the feather detail because I’m tirrrred.
Adobe photoshop, using this for reference
(via scientificillustration)
