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Shark skin adds speed like golf ball

Shark skin adds speed like golf ball

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Sharks can raise their scales to create tiny wells across the surface of their skin, just like the dimples on a golf ball, reducing drag to reach high speeds in the water

Sharks can raise their scales to create tiny wells across the surface of their skin, just like the dimples on a golf ball
Sharks can raise their scales to create tiny wells across the surface of their skin, just like the dimples on a golf ball

The minute scales, which are just 200 micrometres long, are made from tough enamel, such as that found on teeth, giving the skin a rough texture like sandpaper. Lying flat, they had previously been found to reduce drag as the shark swims. Some reports had also suggested that sharks can bristle their scales, causing them to stand up on end.

Experiments have now revealed that tiny vortices or whirlpools formed within the cavities between the scales.

These vortices form a kind of “buffer layer” between the skin’s surface and the fast-moving fluid, preventing a turbulent wake from forming behind the shark.

Since a wake has a lower pressure than the rest of the fluid, it exerts a backwards pull on an object, decreasing its speed and making it harder to change direction.

Eliminating this wake decreases the overall drag on the shark, allowing it to travel faster and move more easily without the thick, syrupy feeling humans get as they try to move through the water.

The same principle explains the dimples on golf balls, which also create mini vortices to reduce drag in this way.

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