When he grabbed the handle, Rupert burst into tears.

Rupert's fall is the physical property of glass, and the glass body is broken due to the unbalanced pressure before and after. Rupert's tears are made by dropping molten glass into ice water and hardening it into tadpoles. Due to the different cooling rates of the surface and the interior, the internal and external stresses are different after curing. Although it is in a balanced state, as long as the fragile tail is damaged, it will explode into powder with the front end. If high-speed photography is carried out, the crushing speed can reach 1450~ 1900 meters per second.

The front end is very hard, and it's okay to hit it with a sharp object.

However, once the back end breaks the whole glass, it will "chaff" …

Experiments and analysis in the film can better understand the mystery.