A drop of Prince Rupert is a strange glass that can withstand a hammer blow

The press squeezes a small, fragile drop of glass. It seems that another second, and it, having broken into millions of fragments, will scatter in all directions. But nothing of the kind happens. What is it? A fantastic movie modeled with a special program or real shooting? Can a glass drop be stronger than metal? It turns out, maybe, if this is not an ordinary drop, but a drop of Prince Rupert himself.

Such a glass body can withstand the pressure of a press or a hammer blow without any damage. But she has one weak point, knowing which, you can easily destroy an unusually shock-resistant glass drop. One has only to break her long tail, as the whole drop shatters to smithereens.

Drops of Prince Rupert, or, as they are also called, Batavian tears - this is nothing like ordinary glass, frozen in a certain way, and therefore it has unique properties. The history of the appearance of these drops goes back centuries, and it is not even completely clear who was the first to invent this miracle: scientists in the laboratory or professional glassblowers. Drops of glass of a similar shape are obtained if the glass cools not in air, but in cold water.

It is believed that they were first obtained in Batavia (the Latin name of the Netherlands), which is why they got the name "Batavian tears". One way or another, but the news of unusual glass drops quickly spread throughout Europe. This unusual glass was brought to England by Rupert Pfaltsky, a 17th-century politician who took part in many important events both in Europe and in America.

The method of producing glass drops of Prince Rupert has long been unknown to the general public. Their strange properties impressed people, many considered them something mystical. And even after the secret of their receipt was revealed, the reason for their unusual strength remained a mystery. And only after centuries, scientists were able to explain what was going on inside this mysterious piece of glass.

Getting into ice water, the glass warmed up to 600ºС starts to cool rapidly. First, the outer layer of glass cools and contracts, forming a kind of shell. In this case, the inner liquid part of the droplet cools more slowly, and such strong compression does not occur, and a strong tension arises between it and the shell. It is this tension that resists external pressure, preventing the amazing drop from cracking under the influence of a press or shock. But it is worth breaking off the long "tail" of the drop, as the magic ends: the whole drop shatters to smithereens due to a violation of the integrity of the shell.

But Batavian tears are not just a wonderful demonstration of physical processes, but also a very interesting phenomenon that has found application in industry. Tempered glass having increased impact resistance, as well as significant heat resistance, is obtained in a similar way. Regular sheet-shaped glass heated to high temperatures is instantly cooled by low-temperature air. It is this method of production that gives it incredible strength.