There was mournful news out of Sweden with the announcement that the world’s oldest known European eel had passed away recently at the age of 155, after living through two world wars, the Cold War, disco, punk, grunge, and the advent of the Internet. Read more
Lauren Bacall, photographed by John Engstead, the year she became Mrs. Humphrey Bogart, 1945.
Sharks have evolved some incredible fluid dynamical abilities. Instead of scales, their skin is covered in microscopic structures called denticles. To give you a sense of size, each denticle in the black and white image above is about 100 microns across. Denticles are asymmetric and overlap one another, creating a preferential flow direction along the shark. When water tries to move opposite the preferred direction, the denticles will bristle, like in the animation above. The bristled denticles form an obstacle for the reversed flow without any effort on the shark’s part. Since local flow reversal is an early sign of separation, researchers theorize that this bristling tendency prevents flow along the shark’s skin from separating. Keeping flow attached, especially along the shark’s tail, is vital not only to the shark’s agility but to keeping its drag low. Researchers have even begun 3D printing artificial shark skin to try and harness the animal’s hydrodynamic prowess. For much more shark-themed science, be sure to check out this week’s "Several Consecutive Calendar Days Dedicated to Predatory Cartilaginous Fishes" video series by SciShow, It’s Okay to be Smart, The Brain Scoop, Smarter Every Day, and Minute Physics. (Image credits: J. Oeffner and G. Lauder; A. Lang et al.; original video; jidanchaomian)
On this day, in 1969, over 400,000 people came out for “Three Days of Peace and Music” at what is now the iconic Woodstock Festival.
AubIn honor of the 45th anniversary, we looked at our own wood stock and found this beautiful 18th century limewood relief. Groovy!
Carved Relief, Aubert-Henri-Joseph Parent, 1789, French. J. Paul Getty Museum.