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Physics Outreach puts a physics spin on bicycles


From cable television to a spin class, Physics and Astronomy Prof. Rafael Lang is there to talk about the wonders of his field.

In 2014, Lang discussed particle physics and dark matter on an episode of “Through the Wormhole with Morgan Freeman.” On May 13, Lang popped by a spin class at the France A. Córdova Recreational Sports Center to explain the physical phenomena around cycling.

During rest moments in the class, Lang brought a bike and some other props to demonstrate force, inertia and balance.  He even hopped on one of the class’ stationary bikes to work up a sweat of his own.

The lesson was a quick Physics & Astronomy Outreach opportunity. One of Lang’s closing demonstrations took a bike chain wrapped around a circular piece of wood. The wood was attached to a high-power drill. After whirling the drill up to full speed, Lang coaxed the chain free, which with of conservation of its momentum, made a path across the floor, maintaining its shape. It bounced as if it was a wheel a few times before slamming into the wall with a loud smack.

“The chain rolled all the way down the hall in the Physics Building,” Lang told the delighted spin class.

Spinning is more than just for a class at the gym. The motion adds stability and allows people of all ages to ride their bikes without falling down. That’s a good spin on physics.

Physics demo in a spin class

Physics and Astronomy Prof. Rafael Lang (right) explains physics concepts to a spin class in the France A. Cordova Recreational Sports Center.


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