The production is to drop the melted glass into ice water, and the surface of the glass will quickly cool to form a hard shell, but the glass under the shell is still liquid. When the liquid in the shell gradually becomes solid, the uncooled liquid glass will shrink into the shell due to the change of the integrated body, which will cause the shell to be under strong pressure and the center will be pulled around.
In other words, if you want to break the internal force balance of Rupert's tears, you can make it fall apart, but its head and body have solid shells, which are difficult to be broken by external forces. Only by letting it break itself from the inside out is the only way.
The origin and application of Rupert's tears;
Rupert's tears were a gift from Prince Rupert of Germany to the king of England in 1660, so it was named after its teardrop shape. The Royal Society has studied it and found some principles of glass manufacturing, which may indirectly promote the production process of 1874 patented tempered glass. And continued to study in the last century and 2 1 century, and then discovered the mystery of Rupert's tears.
By observing the manufacturing method of Rupert's tears, people discovered the method of quenching to produce tempered glass. Through the observation of high-speed camera, it is found that Rupert's tears are so strange because there is a strong compressive stress on its surface and a strong tensile stress inside, and the whole glass is in an unstable state.