Snapping one’s fingers is a universally-understood way of communicating how easily and quickly something can be accomplished. If you want to be a bit more precise, you might want to know just how fast a finger snap is.
A study published in the Journal of the Royal Society Interface examined the biomechanics of finger snapping. Researchers concluded that a finger snap lasts 7 milliseconds — 20 times faster than the blink of an eye. The movement of the middle finger off of the thumb rotates at a rate of 7.8 degrees per millisecond. This approaches the rotation rate of a professional baseball player’s arm but with three times the rate of acceleration.
The study determined, “To the best of our knowledge, the snap of a finger represents one of the fastest recorded rotational accelerations achieved by the human body. However, these velocities and accelerations are still low compared to those achieved by other snapping living systems such as in Mystrium camillae, the Dracula ant, which can achieve velocities up to v = 2.4 × 108° s−1 and accelerations up to a = 1.5 × 1016° s−2.”
The inspiration for the study came from a scene in the movie Avengers: Infinity War, when Thanos snaps his fingers while wearing the Infinity Gauntlet. The researchers wanted to know if it would be possible to snap while wearing a metal glove. They concluded the metal would have interfered with the mechanics needed for a successful snap. Where the Avengers failed, physics should have prevailed.