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)
Water does not resist. Water flows. When you plunge your hand into it, all you feel is a caress. Water is not a solid wall, it will not stop you. But water always goes where it wants to go, and nothing in the end can stand against it. Water is patient. Dripping water can wear away a stone. Remember that, my child. Remember you are half water. If you can’t go through an obstacle, go around it. Water does.
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This image has been licensed by Getty Images as stock photography.
19 April, 2009 at the Layton Commons City Park, Layton, Utah, USA.
Some hand references.
Redid a post by fucktonofanatomyreferencesreborn with sources because they never source anything and I don’t want to reblog that post because I don’t want to support blogs who don’t give credit to people
(No, stating that the art is ~not yours~ and ~came from elsewhere~ IS NOT PROPER CREDIT. Many of these have usernames and such on them but not every single one and you still ought to link back to the specific piece)
I couldn’t source the last one so I didn’t include it.
Retro Conceptual Collages by Adrian Velazco
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