Wet Dog Physics

If there are any duck hunters sitting on the panel to determine the next Nobel Prize for Physics, a Georgia … Continued

If there are any duck hunters sitting on the panel to determine the next Nobel Prize for Physics, a Georgia scientist and his partners just may have a shot at the big prize.

Research conducted by Andrew Dickerson and associates at the Georgia Institute of Technology has determined how fast a wet dog must oscillate in order to dry its fur.

We’ll bet you never associated your Lab’s shaking after he pulls a greenhead from an icy river with physics, did you?

Filming a variety of soaked pooches, Dickerson and his crew created a mathematical model of what happens when wet dogs shake. Scientifically speaking, they reasoned that the water is bound to the dog by surface tension between the liquid and the hair. When the dog shakes, centripetal forces pull the water away. For the water to be ejected from the fur, the centripetal force has to exceed the surface tension.

For a Labrador retriever, they found the amount of force is 4.3 Hertz. (For those non-geeks in the Newshound audience, Hertz (Hz) is a unit of measure in physics that denotes the number of times an event occurs in one second. It is commonly used in measuring the frequency of periodic motion or periodic waves.)

According to the MIT Technology Review, Dickerson took his findings a step further, determining that the radius (size) of a shaking wet animal influences the amount of oscillation necessary to dry itself.

The physicists found that a mouse shakes at 27 Hz, a cat at about 6 Hz, and a bear at 4Hz.

“Shake frequencies asymptotically approach 4Hz as animals grow in size,” the research concluded.

So, just file that information and use it to impress your hunting buddies in the duck blind this winter!