The ‘Wet-Dog Shake’ And Other Physics Mysteries

From 2018: In his book 'How to Walk on Water and Climb Up Walls,' David Hu explores the wonders of the animal world.

Ever wondered why your dog’s back-and-forth shaking is so effective at getting you soaked? Or how bugs, birds, and lizards can run across water—but we can’t? Or how about why cockroaches are so darn good at navigating in the dark?

Those are just a few of the day-to-day mysteries answered in the new book How to Walk on Water and Climb Up Walls: Animal Movement and the Robots of the Future, by Georgia Tech mathematician David Hu.

The book answers questions you probably won’t realize you even had, but they’re questions with serious answers that span the worlds of physics, fluid mechanics, and biology. Throughout the book, Hu demonstrates the extraordinary value day-to-day curiosity brings to science.

But, while he explores how science can reveal wonders of the mechanisms in our world, Hu writes how his work has been the target of politicians for so-called “wasteful” science spending. One of the studies under attack, an inquiry into the average length of urination across the animal kingdom, might have had a laughable premise, but eventually led to serious attention by urologists and researchers working on treatments, prostheses, and artificial organs.

“The concept of waste is based on the notion of a limited gas tank and a single known destination,” Hu writes. “People expect scientists to save gas as they go from A to B. But the real power of science is to take us to destinations that we have never been to.”

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