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The physics of a finger snap are revealed in a new high-speed video.

The friction and compressibility of the finger pads are essential for a quick snap.

Everything happens in an instant. A new high-speed video reveals the blink-and-you'll-miss-it physics of finger snapping.

The footage shows the extreme speed at which the gesture occurs, as well as how friction and the compressibility of the finger pads are critical to humans' ability to snap properly, researchers report in the Journal of the Royal Society Interface on November 17th.

Finger snaps last about seven milliseconds, which is roughly 20 times faster than an eye blink, according to biophysicist Saad Bhamla of Georgia Tech in Atlanta. The team discovered that after slipping off the thumb, the middle finger rotates at a rate of up to 7.8 degrees per millisecond, which is comparable to what a professional baseball pitcher's arm can achieve. A snapping finger accelerates nearly three times faster than a pitcher's arm.


The team discovered that when fingers were covered with high-friction rubber or low-friction lubricant, they made snaps that fell flat, indicating that bare fingers have a level of friction ideal for a quick snap. The friction between the thumb and middle finger stores energy before it is suddenly released. A lack of friction results in less pent-up energy and a slower snap. However, too much friction slows the snap by impeding the finger's release.

A scene from the 2018 film Avengers: Infinity War inspired Bhamla and his colleagues. Thanos, the supervillain, snaps his fingers while wearing a supernatural metal glove, wiping out half of the universe's life. The team wondered if they could snap while wearing a rigid glove.

When the fingers snap together, they compress, increasing the contact area and friction between them. So the researchers experimented with snapping with hard thimbles on their fingers. The snaps were, indeed, sluggish.

As a result, Thanos' snap would have been a failure. Physics saves the day without the need for superpowers.

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