Why is there noise when pulling your fingers?

Clapping your hands will make a gurgling sound, which is the sound of bubbles bursting at the joints, not the sound of bones.

Can you press your finger twice in five minutes?

Many people like to pull their fingers and knuckles. Don't think this is a very simple thing. In fact, no one's finger joints can ring twice in five minutes. Try it yourself if you don't believe me: prepare a watch, break a joint of your finger first, and start timing when you can't hear the noise. If you can ring the bell to the same place again in five minutes, you win.

The noise of finger joints is caused by the bursting of air bubbles. There is a certain amount of liquid in human finger joints, and a small amount of gas is dissolved in the liquid.

When the finger joint is stretched, the pressure on the liquid is reduced, and the gas originally dissolved in the liquid escapes from it (this phenomenon can also occur when the soda bottle cap is opened). But the bubbles in the knuckles can't go anywhere else. In about fifteen minutes, the bubble will be absorbed by the liquid in the finger joint again, so if you want to ring your finger again, you must wait patiently for fifteen minutes, which is impossible.