Why Are Banana Peels Slippery?

If you want to trip someone up, leave a banana peel in his path. Everyone knows that nothing is more slippy than the discarded skin of one of our favorite fruits. If you aren’t convinced, you just have to ask Wile E. Coyote or any other cartoon character whose bottom has slammed onto the ground after an unfortunate encounter with a banana skin.

Although this truth about bananas has been known for ages, the reason for it has always slipped away from scientists. Thanks to intrepid researchers, however, we now know the physics that explain why watching someone fall on a banana peel is so fun.

Japanese researchers Kiyoshi Mabuchi, Kensei Tanaka, Daichi Uchijima, and Rina Sakai peeled the secrets away in their groundbreaking study “Frictional Coefficient under Banana Skin” (Tribology Online 7, no. 3, 2012, pp. 147-151). They combined their considerable smarts to ponder the amount of friction between a shoe and a banana skin, and between a banana skin and the floor, when a person steps on a banana skin that’s on the floor.

The chemical substance that makes banana peels are especially slippery is the polysaccharide molecule. These molecules are also in the membranes at the point where the bones in the human skeleton meet. Scientists believe that a better understanding of the slipperiness of banana peels can help improve prosthetics designs and lead to advancements in orthopedic medicine.

For their contribution to human understanding, the researchers were awarded the 2014 Ig Nobel Prize in physics.

The results of the study are certainly noteworthy. We really wish we would have been asked to help with the research. What better way to spend an afternoon than sitting around and video recording a bunch of people falling ingloriously on their bottoms?

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