Perfect finger snapping relies on physical concepts like friction and acceleration, thanks to which we know Thanos couldn’t have snapped his fingers in the Avengers movie.
Take a good look at this video because it shows the physics of snapping a finger. It happens in the blink of an eye.
Video captures in slow motion something that happens in an instant. The fingers of the hand move at high speed and produce the characteristic sound. According to researchers, the trick to achieving a perfect snap lies in two factors: friction and compressibility of the fingertips.
How long do you think a snap lasts? It’s just seven milliseconds. That’s about 20 times faster than the blink of an eye, explains Saad Bhamla, lead author of the experiment.
The earliest recorded depiction of a finger snap dates back to 320 BCE in Greece.
Bhamla led a team that used high-speed video to study this movement. After sliding the thumb, the middle finger moves at a speed of up to 7.8 degrees per millisecond. The speed is close to that of a professional baseball player’s arm when throwing the ball. But also, a snapping finger accelerates nearly three times faster than a pitcher’s arm. Speed and acceleration are the secrets of the snapping sound.
The first recorded snap of all
Scientists analyzed the friction of the fingers that produced the snap in two cases. In one, by covering the participants’ fingers with high-friction rubber and, in the other, with low-friction lubricant. Both techniques failed and did not produce satisfactory snaps.
Instead, the fingers without any substance provide the ideal friction for a fast, loud snap. Friction between the thumb and middle finger allows energy to be stored and then suddenly released. Very little friction means less potential energy and a slower snap. However, excessive friction makes it difficult to release the finger and also delays snapping.
The earliest recorded depiction of a finger snap dates back to 320 BCE in Greece. A piece of pottery depicts Pan, the god of nature, dancing with his right hand folded in a snapping finger position.
(a) A piece of pottery from 320-310 BCE, depicting Pan, the Greek god of nature, dancing with a Maenad with his hand curved in the shape of a snap of his fingers. (b) Composite image of motion at different timestamps from a side view. (c) Kinematics and dynamics of snapping fingers. (d) Frontal finger snap frames showing visible compression of the fingertip as energy is stored before being released and causes movement of the thumb and middle finger. Source: Journal of the Royal Society
Thanos couldn’t snap his fingers
Bhamla’s team was inspired by a scene from the Avengers saga movie Avengers: Infinity War from 2018, when supervillain Thanos snaps his fingers while wearing a glove with unlimited power and makes half the living things in the universe disappear.
The researchers wondered if Thanos could have snapped his fingers with such a bulky gauntlet. The fingers usually compress when pressed together and ready to snap, which increases the contact and friction between the fingertips. To verify this, the scientists tried to cover the fingers with thimbles, but a metal cap blocked the compression and snaps were slow.
Superhero 0 – Physics 1. Thanos’ snap would have failed.
REFERENCE
The ultra-fast snap of a finger is mediated by skin friction