A drop of Prince Rupert. Paradox Drops of Prince Rupert

), or "Danish tears". The head of the drop is incredibly durable, it is very difficult to mechanically damage by compression: even strong blows of the hammer or hydraulic press do not apply any harm to it. But it is worth a slightly fragile tail, and the whole drop in the blink of an eye will split into small fragments.

This curious property of a glass drop was first discovered in the XVII century whether in Denmark, or in the Netherlands (hence another of their name - Batavales), or in Germany (contradictory sources), and an unusual thing quickly spread to Europe as a funny toy . The drop was obtained in honor of the commander-in-chief of the English royal cavalry of Rupert Pataltsky, famous for the people as Prince Rupert. In 1660, Rupert Palatsky returned to England after a long expulsion and brought with him unusual glass drops that Karl II presented with him, and he transferred them to research to the London Royal Society.

Drop manufacturing technology was kept secret, but as a result it turned out that it is very simple: it is enough to drop the molten glass in a bucket with cold water. In this simple technology and lies the secret of the strength and weakness of the drop. The outer layer of glass is quickly frozen, decreases in volume and begins to put on the still liquid kernel. " When the inner part also cools, the kernel begins to shrink, but now it is oppressed by the already frozen outer layer. With the help of the intermolecular forces of attraction, it holds the cooled core, which is now forced to take a greater volume than if it cooled freely. As a result, on the border between the external and inner layer There are opposing forces that pull the outer layer inside, and the compression voltage is formed in it, and the inner kernel is outward, forming the tension voltage. In this case, the inner part may even break away from the outer, and then the bubble is formed in the drop. This confrontation makes a drop of stronger than steel. But if you still damage her surface, breaking the outer layer, the hidden voltage force is released, and the rapid wave of destruction ride along the entire drop from the place of damage. The speed of this wave is 1.5 km / s, which is five times faster than the speed of sound in the atmosphere of the Earth.

The same principle underlies the manufacture of tempered glass, which is used, for example, in motor vehicles. In addition to high strength, such glass has a serious security advantage: when damaged it is divided into a plurality of small pieces with stupid edges. The usual "raw" glass flashes on large sharp fragments that can be seriously injected. Tempered glass in the automotive industry is used for side and rear windows. The windshield for cars make a multi-layer (triplex): two or more layers glue with a polymer film, which while hitting the fragments and does not allow them to fly away.

Veronica Samtkaya

A drop of Prince Rupert looks like a glass tadpole, created by a newcomer glass, but it is so strong that it is impossible to break it even with a hammer. However, it is enough to hit it in the "tail", and it crumbles into powder. The reason for such inexplicable qualities, scientists tried to find for almost 400 years, and now the team of researchers from Cambridge University and Tallinn technical University In Estonia, finally there is an answer.

The Batavian tears or Drops of Prince Rupert first appeared in the 17th century and became famous when Prince Rupert Bavarian presented five of these strades to the king of England Karl II. They were transferred to the Royal Society for studying in 1661, however, despite almost four centuries of research, the explanation of their strange qualities was found only now. Drops are made of molten glass with a high thermal expansion coefficient, and lowered into a cold water vessel. The molten glass instantly freezes in the characteristic form of a drop.

To study the droplets of Prince Rupert, scientists used the technique where the transparent 3D object is installed in an immersion bathroom so that polarized light passed through it. Changes in the polarization of light inside the object correspond to voltage lines. The previous work of Tallinn and Cambridge physicists, spent back in 1994, included shooting a drop of droplets at a speed of almost a million frames per second. You can see the video, as after damage to the "tail", cracks spread dropwise at a speed of about 6,500 kilometers per hour.

A new study showed that the stress of glass compression in the "head" of the drop is about 50 tons per square inch, which makes it equal to steel. This is happening, because outside the drop cools faster than inside. Thus, a huge pressure is injected at the head "head" of drops, which is compensated by stretching.

While these forces remain in equilibrium, the drop is very durable and can withstand significant loads. But with damage to the "tail", this equilibrium is broken, and many small cracks spread parallel to its axis. This happens at such a high speed, which resembles an explosion.

Let me introduce you to one of the interesting properties of glass, which is customized with drops (or tears) of Prince Rupert. If drip molten glass in cold waterIt will freeze in the form of a drop with a long thin tail. Because of the instant cooling, the drop acquires an increased hardness, that is, it is not so simple to crush it. But it is worth a slim tail in such a glass drop - and she will immediately explode, scattering around her finest glass dust.

Glass drops were invented in Germany in 1625. In the XVII century, it was the opinion that glass tears actually came up in Holland, so they were wrong to call "Dutch". In Britain, glass tears became known thanks to the British Duke Rupert Patalsky. He presented them with the king of Karl II, who, in turn, handed them to the Royal Scientific Society. In honor of the duke, glass tears began to call "Rupert's drops". The method of manufacturing drops of Duke Rupert for a long time was kept secret. They were sold to everyone like fun toys.

Today, the mechanism of "work" of Dutch tears is carefully studied. If the molten glass enters cold water, it quickly freezes, accumulating incredible mechanical stress. Conditionally lay down in a drop outer layer and inner core. The drop is cooled from the surface, and its outer layer is pressed and decreases in volume until the kernel remains liquid and hot.

After the temperature drops inside the ball, the kernel will begin to shrink. However, the process will resist the solid outer layer. With the help of the intermolecular forces of attraction, he tenacles the core, which, having cooled, is forced to take a greater volume than if it cooled freely.

In a consequence, on the border between the outer layer and the core there will be forces pulling the outer layer inside, creating compression stresses in it, and the inner core - outward, forming tension voltage in it. These voltages with too fast cooling are very significant. So the inner part of the ball can break away from the outer, and then the bubble is formed in the droplet.

If you break the integrity of the surface layer of the tear, the voltage force is immediately released. Frozen glass drop is very strong. She easily withstands the punch with a hammer. However, if you turn her tail - it is destroyed so rapidly that it rather looks like a glass explosion.

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A tear of Prince Ruperta, Batava or Dutch drops, a tear of the devil - all these are the names of the same physical phenomenon. The round part of such tears is heavy-duty glass, and her tail is its Achilles heel, which, having rolled, turns the whole design into dust.

Opinions regarding the origin of the droplets of Prince Rupert are very diverse. Some sources indicated that they invented them in 1625 in Germany. But they are also called "Batavi tears" and that is why.

How to open a drop of Prince Rupert

Once in Holland, unfamiliar to us, the scientist spent a certain interesting experiment. He melted a glass wand on a powerful burner, and liquid molten droplets shake into a tank with ordinary water. Glass drops, frozen in cold water, purchased a bizarre shape, reminiscent of tadpoles with a rounded head and a thin snake-shaped tail. The opening was impressed by the researcher, and he gave his discovery name - the Batavian tears in honor of Batavia - the former name of his homeland. As it turned out, this discovery of the scientist was not limited to, because later he discovered their curious property.

It is believed that glass is quite fragile material. But the property of these glass drops is such that even with numerous blows with a hammer in a rounded part, they are not broken. At the same time, if during the experiment to put this drop under the press on the metal plate, then it will remain a drop-shaped imprint. But it is worth only to abandon the tip of her thin tail, and it instantly explodes on a million smallest fragments.

Anyway, the Batavian brightness of Bataves received wide fame after the British Duke Rupert Palavsky presented them as a wonderful gift to the king of the UK Karl II. After the king instructed the royal scientific community to explore their mysterious and funny nature. In honor of the prince of Palavsky, the Batavian tears began to be called not otherwise as glass drops of Prince Rupert. The way to create them was kept in the strictest secrecy for a long time, but they could buy them anyone as a raised souvenir.

Why the drop of Prince Ruperta explodes

To date, the reasons for the unusual behavior of glass drops have already been scientifically proven. The fact is that getting into cold water, glass drops are quickly frozen. Inside each of them, high mechanical stress is formed. If you imagine that the drop consists of a shell and nucleus, it can be understood that it starts to bother first at the surface, that is, her shell decreases and compressing while the kernel continues to be hot and liquid.

When the inner temperature of the drop is declining, the kernel also begins to shrink, but now resistance occurs due to the external frozen layer. Close intermolecular bonds allow it to squeeze the kernel, which is already increasing.

A very strong voltage occurs between the shell and the core, respectively, compression on the outer layer and stretching is on the internal. If you omit the molten glass into too cold water, the voltage level will reach the maximum and allow the inner part of the drop to separate from the outer, forming a bubble.

It is the internal strengths of the voltage of compression and stretching resist any power of impact. Lotoming the "tail" drops, we destroy the top layer, which will allow the inner pressure of stretching to earn in full strength, and a glass drop will spread to dust. This internal voltage is so large that the explosion occurs literally for one moment. Therefore, by conducting an experiment, be sure to be equipped with protective glasses.

Recently, a group of scientists from different parts of the world set forth the goal of "to do" to the truth and find out why and how exactly the explosion occurs when the rope of Prince Ruperta drops.

The fact is that when there is damage to the outer shell, a crack appears, penetrating directly into the "heart" of a drop, where the potential voltage is concentrated.

Having in mind the scientifically proven fact that the outer layer is compressed, and the internal - stretched, scientists considered, exactly how the pressure inside the tears is distributed. It turned out that the force of compression at the outer shell exceeds the atmospheric pressure of 7,000 times and comes to 700 megapascals. This is incredible, given that the surface of glass tears is unusually thin and its area is only 10% of the entire body of the drop.

The researchers also found that in order to explode Prince Rupert's drop, it takes cracks to reach her center. When hitting the hammer or with any other effect on the head head, the cracks are dissipated along its surface, not penetrating into the internal stretching zone. This explains the strength of the ball. With the destruction of the "tail" cracks, it is possible to penetrate into the inner part of the glass tears, which entails an explosion.

Modern use of the Effect Drops of Prince Rupert

The principle of the behavior of a drop of Prince Rupert is already successfully applied in industry. Such glass is familiar to everyone like "tempered."
Previously, "hardened glasses". They could be without a branch of conscience to drop on the floor - it was never broken when he hit. But the randomly appeared on the edge of Shcherbinka could provoke his explosion at any time. Therefore, with such dishes it was worth it to turn even more carefully than with an ordinary glass.

According to a similar principle, automobile glass is made today. In addition to the fact that it has a higher strength, it has another important advantage for passenger safety - in case of damage, it crumbles into small pieces with rounded edges. Raw glass breakdown, form sharp and large fragments that can be seriously damaged.
From the tempered glass, the side and rear windows are made, the windows are made by gluing several layers of such glass with the help of a special polymer film, which in the event of an accident will not let them fly out at all.

Video about the effect of a Kapli Prince Ruperta

Prince Rupert (Ruprecht Von Der Pfalz) was an outstanding German military who received the title of Admiral and commanded the Royal Connection during the civil confrontation in England. He was a native of Prague, had a county title, he was called Duke Bavarian, but most of all he is known as Prince Rupert Rhinean. His father is a short time of rules to the Bohemia region, but later was forced to flee into the Netherlands, where Rupert spent his childhood. Having received education, Rupert became a soldier and participated in the thirty-year war, there was a valuable military experience. Later he joined the Army of Charles I in the English Civil War and took the post of head of the cavalry. With numerous military victories, the commander has earned a good reputation, then continued the struggle for the city of York, but failed to defeat, having lost this city and north of England. Rupert also took part in the Battle of Neuzbi, in which Bristol won and won. Subsequently, the prince was sent to the exile in Holland, spent the following several years, managing small naval squadrons in West Indies and Germany. Later, when restoring the monarchy, Rupert returned to England, where he conducted a number of British naval operations, and also fought in the second and third english-Dutch Wars.

Rupert Pfaltsky was born on December 17, 1619 in Prague, Bohemia, in the family of Friedrich V, heads of the Protestant Union and his wife Elizabeth Stewart, Yakov's daughter I and Anna Danish. In 1620, after a collision with its enemies Catholic in the battle on the White Mountain, Rupert's family fled from Bohemia to Holland, where he spent most of his childhood. Rupert was a gifted child and learned to speak English, Czech and french At the age of three years. He studied german At a young age, and also succeeded in art. When he turned 13 years old, the boy lost his father. He lived his teenage years in England in his uncle's family, King Charles I. Rupert became a fairly early soldier. In 1638, fighting in the thirty-year war (1618-1648), which brought him a significant military experience, Prince Rupert was captured and imprisoned for three years in prison in Linz.

For several months after his release from captivity in Germany in 1641, Rupert went to England and joined Karl's Korla's short before the start of the civil war in England in August 1642. Having the opportunity to lead the command of the Royal Connection at the age of 23, he skillfully sent his troops and won a large number of battles He defeated the enemy's forces near the wooler, and then fought in the first major battle civil War With Edgehill in October 1642. In July 1643 they were taken by Bristol, and then released Newark, Nottinghamshire, in February 1644. In the same year, Rupert headed the siege of York, but suffered, losing york and north of England. When the prince passed Bristol, the king removed him from service and expelled from England in July 1646. In 1660, after the restoration of the monarchy, this warlord returned to England to implement a high-ranking command. He was appointed a secret adviser and took part in the second (1655-57) and the third (1672-1674) of the English-Dutch wars. In 1670, Rupert Pafaltsky became the first governor of the Gudsonian Gulf, and also showed great interest in science and presented the art of mezzo-tinto in England. He was also one of the founders of the Royal Society.

Rupert had romantic ties with Francis Bard, the daughter of the English researcher and the veteran of the Civil War, Henry Barda. Although he denied Francis's statements about their secret marriage, but, nevertheless, he recognized his son Dudley Barda. At the end of the 1660s, the prince was in love with Margaret Hughes, an attractive actress of the Krury Lane Theater. The couple did not secure her relationship with marriage, but Rupert admitted her daughter Rupert. This outstanding german soldier He died on November 29, 1682, in his house, in Westminster, in England after the attack of pleurite at the age of sixty.