The exploding blob of prince rupert. A drop of Prince Rupert. What is and how to do it What kind of material prince rupert

Do you know? I'll be honest, I didn't know. But judging by the information on the Internet, this is a long-standing and very popular topic! Think what it's like? Tell us later in the comments, and now we will look at this process in all its glory, and who knew, maybe they will find out the details!

This is one of the interesting properties of glass, which is popularly called "Prince Rupert's drops" (also known as Rupert's balls or Dutch tears)

Making a drop of Prince Rupert is very simple. Simply take hot glass and drop it into a bucket of water. As a result of the fact that the water quickly cools the outer surface of the glass, the temperature inside remains significantly high. When the glass finally cools, it shrinks within the shell of the already hard outer shell. Due to this compression, a very strong compressive stress is created on the outer part, while the inner part is under tensile stress. As a result, we have something in the form of tempered glass, although not quite.

But what's so amazing about a drop of Prince Rupert? Unlike ordinary glass, this drop cannot be broken even by hitting it very hard with a hammer - at least if you hit the main part of the "drop". At the same time, if the "tail" of a tear is slightly damaged, it explodes like a grenade - however, this can only be seen with a camera capable of shooting at a speed of 100,000 frames per second. That's what you can see in the video above.

The speed of the fault is approximately 4,200 km per hour.

What kind of prince is this? And now we find out!

Prince Rupert, cousin of King Charles II, had about as many titles as natural talents: Count Palatine of the Rhine, Duke of Bavaria, Count of Holderness, Duke of Cumberland, part-time cavalryman, sailor, scientist, administrator and artist.

His father, Friedrich von Palatinate, was king of the Czech Republic for exactly one winter, and spent the rest of his life in Holland. Even as a child, Rupert mastered the main European languages, demonstrated good mathematical abilities and talent as a draftsman. Rupert began his military career at the age of 14, accompanying the Prince of Orange at the siege of Rhinberg. Two years later, during the invasion of Brabant, he entered the service of the prince's guard, and the following year, together with his older brother, he visited English relatives, making an extremely favorable impression on Charles the First. From this trip he returned with an honorary degree of Master of Arts, awarded to a distinguished guest at Oxford.

In 1637, Rupert participated in the siege of Breda, after which, together with his brother and a detachment of Scottish mercenaries, he went to fight in Westphalia, where in the autumn of 1638 he was captured. Until 1641, he languished in prison, and at this time Lord Arundel, the English ambassador in Vienna, presented the prince with a dog, which later gained great fame.

It was a white poodle, allegedly smuggled out of Turkey, where the Sultan forbade foreigners to purchase dogs of this breed. "It was extremely curious to see how this impudent and restless man amused himself by teaching a dog a discipline that he himself had never known." The poodle, given the unpretentious nickname Boy, invariably accompanied Rupert until his death at the Battle of Marston Moor. The poodle was eagerly remembered in the pamphlets of the "roundheads", for example, in one engraving he is depicted growling at the members of Parliament dissolved by Cromwell. Boy enjoyed many privileges - slept in the master's bed, used the services of more barbers than Rupert himself, and received the most tidbits from the hands of King Charles, who condescendingly allowed Boy to sit in his chair. According to rumors, the dog was very smart. So, at the word "Karl" he began to joyfully jump and was very fond of listening to the liturgy, turning his muzzle towards the altar. This, obviously, caused rumors that a spirit follows Rupert in the form of Boy, they say, the dog can become invisible and participates in necromancy sessions conducted by its owner. And the poor fellow was killed. The fight was, as they say, a silver bullet.

Let's return to the prince :) In addition to training Boy during the years of imprisonment, Rupert also conducted theological conversations with confessors, resisting attempts to convert him to Catholicism, improved his skills as an engraver, read books on military art and started an affair with the daughter of the governor. Thanks to the efforts of Charles the First, Rupert received his freedom on the condition that he never again turn his weapon against the emperor. In August 1642, the Prince, with his younger brother Moritz, arrived in England at the head of a detachment of English and Scottish veterans of the Continental Wars to take the King's side in a civil war with Parliament. Granted by the Order of the Garter, Rupert stood at the head of the royal cavalry, but soon the joy of his arrival was far from universal. Although Rupert was an experienced soldier, he had a youthful ardour, which, along with foreign manners, repelled the king's respectable advisers. In particular, their understandable dissatisfaction was caused by the statement of the prince that he wants to receive orders exclusively from his august uncle. Youth has done Rupert a disservice. At the Battle of Edgehill in October 1643, his cavalry completely defeated the parliamentary cavalry, but, carried away by the pursuit, Rupert left the battlefield, thus depriving the royalist forces of the chance to inflict a decisive defeat on the roundheads.

The prince showed remarkable energy, combining administrative work with the conduct of hostilities during the years 1643-44: he took Bristol, ruled Wales, lifted the siege from York ... After the defeat at Marston Moor, Rupert stood at the head of the royalist army, nominally led by the Prince of Wales. Internal disagreements and a number of objective reasons led to the defeat at Naesby, after which Rupert doubted the successful outcome of the war for the king and advised Charles to come to an agreement with Parliament. This was regarded as a malice, which the king was finally convinced of after the prince surrendered Bristol to parliamentary troops. The king dismissed Rupert, who appeared in Newark and demanded a trial, as a result of which he was returned to his good name, but not command. In 1646, Princes Rupert and Moritz were expelled from England already by order of Parliament.

On the Continent, Rupert led detachments of English emigrants who entered the French service, and commanded them in military operations against Spain. After the outbreak of the second civil war in England, the prince tried himself as a sailor with varying success. In 1649, he and Moritz received command of 8 ships and went to Ireland under the command of the Marquis of Ormond, where he continued the glorious English tradition - he robbed strangers and handed over the loot to his own. Parliamentary Admiral Blake was sent to put an end to these atrocities, and Rupert sailed for Portugal, where he was promised shelter, but Blake caught up with him in the port of Lisbon. Exposed as a pirate, the prince sets off on a free voyage across the Mediterranean and the Atlantic. In the spring of 1652, Rupert sailed to the shores of West Africa, where he was wounded in battle with the natives. He sailed for the West Indies in the summer of 1652, only to find that the Royalist enclave in Barbados, where he had hoped to find refuge, had capitulated to the Commonwealth. In the autumn, on the way from the Virgin Islands, two of Rupert's four ships were lost in a storm, one of them was commanded by Moritz. Depressed by the death of his brother, the prince returned to Europe in 1653.

Rupert was warmly welcomed at the court of the exiled king Charles II in Paris, but the courtesies faded in proportion to how it turned out the exact amount of booty he brought from the West Indies. The disillusioned prince spent the next six years in obscurity, having quarreled over the inheritance with his older brother.
After the restoration of Charles II in 1660, Rupert returned to England and was well received by the king, despite earlier disagreements. He received an annual pension and was appointed to the Privy Council in 1662, the condition of the navy being of particular concern to him. Rupert also took an interest in overseas business ventures, becoming the first governor of the Hudson's Bay Company in 1670. The territory granted to the Company was named "Prince Rupert Land" in his honor. He was also an active shareholder of the Africa Company. Rupert's contribution to the development of trade was marked by a personalized stone laid at the foundation of the new Royal Exchange. The prince as admiral took an active part in the Second and Third Anglo-Dutch Wars, playing a significant role in the battle of Lowestoft and in the victory on St. James's Day (July 25, 1666). From 1673 Rupert devoted himself to the administrative work of the admiralty. He died at the age of 62 in 1682 and is buried with honors at Westminster.

Continuing to show interest in scientific experiments, Rupert became one of the founders of the Royal Society. In particular, he experimented with the production of gunpowder (the method he proposed made gunpowder 10 times more effective), tried to improve guns, invented an alloy known as "prince's metal", and also developed a device for, so to speak, deep diving :) The prince formulated a mathematical problem of the "Rupert's Cube", achieved notable success as a coder, built a watermill in the Hackney marshes, developed a naval tool which he named the Rupertinoe, devised a mechanism for ensuring the balance of the quadrant when measuring on board a ship, tried to improve surgical instruments and was the author of outstanding engravings.

As for his personal life, Rupert never married, but left behind two illegitimate children: son Dudley (1666) from Francis Byrd and daughter Rupert (1673) from actress Margaret Hughes (Hughes). The latter, thanks to her connection with Rupert, became the first professional actress in the English theater; in 1669, Margaret, along with male actors, enjoyed the privilege of "royal servants" - she could not be arrested for debts. This was very helpful, because she led a wasteful lifestyle. During their relationship, Rupert gave her £20,000 worth of jewelry, among them Palatinate family jewelry, and also bought a mansion for Margaret for another £25,000. Rupert liked family life - or its semblance - he noted with pleasure, watching his little daughter: "She already rules the whole house and sometimes even argues with her mother, which makes us all laugh." It is believed that Margaret became Rupert's morganatic wife. He bequeathed his property equally to her and his daughter.

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

This curious property of a glass drop was first discovered in the 17th century, either in Denmark, or in Holland (hence another name for them - Batavian tears), or in Germany (sources are contradictory), and an unusual little thing quickly spread throughout Europe as a funny toy . The drop got its name in honor of the commander-in-chief of the English royal cavalry, Rupert of the Palatinate, popularly known as Prince Rupert. In 1660, Rupert of the Palatinate returned to England after a long exile and brought with him unusual glass drops, which he presented to Charles II, who transferred them to the Royal Society of London for research.

The technology for making the drop was kept secret for a long time, but in the end it turned out to be very simple: just drop molten glass into a bucket of cold water. In this simple technology lies the secret of the strength and weakness of the drop. The outer layer of glass solidifies quickly, decreases in volume and begins to put pressure on the still liquid core. When the inner part also cools, the core begins to shrink, but this is now counteracted by the already frozen outer layer. With the help of intermolecular forces of attraction, it holds the cooled core, which is now forced to occupy a larger volume than if it had cooled freely. As a result, opposing forces arise at the boundary between the outer and inner layers, which pull the outer layer inward, and a compressive stress is formed in it, and the inner core outward, forming a tensile stress. In this case, the inner part can even break away from the outer, and then a bubble forms in the drop. This opposition makes the drop stronger than steel. But if, nevertheless, its surface is damaged by breaking the outer layer, the hidden force of tension will be released, and a rapid wave of destruction will sweep from the place of damage along the entire drop. The speed of this wave is 1.5 km/s, which is five times faster than the speed of sound in the Earth's atmosphere.

The same principle underlies the manufacture of tempered glass, which is used, for example, in vehicles. In addition to increased strength, such glass has a serious safety advantage: when damaged, it breaks into many small pieces with blunt edges. Ordinary “raw” glass shatters into large sharp fragments that can seriously injure you. Tempered glass in the automotive industry is used for side and rear windows. The windshield for cars is made multi-layered (triplex): two or more layers are glued together with a polymer film, which, upon impact, holds the fragments and prevents them from flying apart.

Veronika Samotskaya

Prince Rupert's Drop is a glass artifact that has two opposite properties: it is extremely strong and extremely fragile at the same time.

The blob looks like a tadpole with a bulbous head and a long, thin tail. The head is so strong that it can withstand a blow from a hammer, and bullets fired at it at close range are destroyed on impact - yes, it is bullets, not glass. However, if you flick the tail of the drop with your finger, it will turn the entire drop, including the solid glass head, into powder.

Prince Rupert's drops (also known as "Batavian tears" and "Bolognese flasks") are formed by placing liquid glass in cold water, causing the outer surface of the drop to solidify immediately, while the glass inside remains molten. The cooled outer layer tries to contract while the molten inner layer tries to expand. In the process of crystallization, the opposing forces acting on the drop head make it unusually strong and brittle at the same time. It looks like a stone arch - the structure is under extreme stress, which is exactly what does not allow it to fall apart. But if you remove the keystone, the arch will collapse.

Prince Rupert drops were first discovered in Germany in the 1640s. They were originally created by glassmakers in Mecklenburg, Northern Germany, and were sold as toys and curios throughout Europe, where they were called variously, such as "Prussian tears" or "Dutch tears". Glassmakers carefully guarded their secret, which led to a number of theories as to how the drops were made.

An amateur scientist from England, the Duchess Margaret Cavendish, after several weeks of experiments with dozens of samples in her laboratory, came to the conclusion that a small amount of volatile material was introduced into the head of the drop, which reacted violently on contact with air.

In 1660, Prince Rupert of the Palatinate, Duke of Cumberland and one of the founders of the Royal Society, brought some glass drops with him to demonstrate them to scientists and King Charles II. As you probably already guessed, they were named after him.

Robert Hooke, who was in charge of conducting experiments to members of the society, made an important breakthrough by suggesting that it was the cooling of the glass after being immersed in water that caused the strange property of the drops, although a fuller understanding of the mechanics did not become available until three centuries later.

It wasn't until 1994 that scientists at Purdue University and the University of Cambridge, using high-speed framing to observe the process of drop breaking, came to the conclusion that the surface of each drop was subjected to a high compressive load, while the inside was under the influence of high stress forces - in a state of uneven balance, which can be easily disturbed by breaking the tail. Experiments show that the bulbous head is capable of withstanding a compression force of up to 7,000 kilograms per square centimeter. It has also been estimated that destructive cracks propagate along the tail and head at an astounding speed of 6,500 kilometers per hour.

Later, collaborating with the Tallinn University of Technology in Estonia, the researchers found that in order to break a drop, you need to create a crack that can penetrate into its internal stress zone. The outer compression layer is very thin: it is only about 10 percent of the diameter of the drop head, but it has an incredibly high strength. Since surface cracks tend to propagate parallel to the surface, they cannot enter the stress zone. But if the tail cracks, the cracks will enter the stress zone and release all the stored energy, causing the drop to collapse.

Tempered glass, which is usually used in the manufacture of cars and mobile phones, is made according to the same principle. It is quickly cooled in molten form with cold air, creating an internal tension that allows the surface to remain compressed all the time. The compression prevents cracks from growing, but when the glass finally breaks, it shatters into thousands of small pieces. This is why car windshields shatter into small pieces on impact, but they are covered with a special layer of adhesive that prevents particles from entering the car interior and causing injury to passengers.

“Tensile stress is what usually causes materials to break in a manner similar to tearing a sheet of paper in half,” says Koushik Viswanathan of Purdue University. "But if you change the tensile stress to a compressive one, then you make it harder for cracks to propagate, and that's exactly what happens in the Prince Rupert drop head."

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Today I found something new and interesting for you, although it may be new only for me, but it will definitely be interesting for everyone - drops of Prince Rupert. Let's figure out what these drops are and why they are interesting ...

What are Prince Rupert drops

Prince Rupert drops are glass drops with a thin tail, which are the result of placing molten glass in water. And the interesting thing about them is that it is almost impossible to crush, trample, smash or destroy them in any other way available to people, but this only applies to the drop itself, but it also has a thin tail, in which the vulnerability of a seemingly indestructible thing is hidden, and if it break, then there is a real glass explosion. See for yourself how they unsuccessfully try to crush the drop of Prince Rupert with a hydraulic press:

and how it easily explodes when the thin tip is damaged:

Well, what an interesting effect?

Let's see how such an interesting result is obtained? To do this, you need to understand how drops of Prince Rupert are obtained.

How to make Prince Rupert drops

In order to make drops of Prince Rupert, molten glass must be placed in water. When molten glass enters cold water, it solidifies very quickly with the simultaneous accumulation of enormous internal stress. Moreover, cooling occurs at least quickly, but not instantly, so when the surface layer has already cooled down, solidified and decreased in volume, the inner part of the drop, let's call it conditionally the core, is still in a liquid and molten state.

Further, the core begins to cool and shrink, but intermolecular bonds with the already solid outer layer prevent it from shrinking, as a result of which, after cooling, the core occupies a larger volume than if it were cooled in free form.

Because of this, forces with the opposite direction act on the boundary of the outer layer and the core, which pull the outer layer inward and the core outward and create, respectively, a compressive stress for the outer layer and a tensile stress for the inner core. As a result, we have a huge internal stress, which makes the drop very strong, but at the same time, any damage to the outer layer leads to a violation of the structure and a glass explosion, but since the thinnest place is the tail, it is through it that the outer layer can be destroyed in order to to get such a beautiful explosion as in the video above or in the photo below:

And this video is for those who find it easier to perceive video information than to read a lot of letters:

When and where were Prince Rupert's drops discovered?

The drops of Prince Rupert were first discovered in Germany in 1625, but how often it was believed that they were discovered by the Dutch, or maybe it sounded more beautiful, because everything foreign causes more curiosity, these times do not change, hence the second name for these drops - Dutch tears.

And here Prince Rupert asks the reader? The fact is that Prince Rupert, the British duke, was the person who brought these drops to England and presented them to the English monarch Charles II. The king really liked the interesting glass drops and he gave them to the British Royal Scientific Society for study. In honor of these events, curious drops began to be called the drops of Prince Rupert, and this name has been perfectly preserved to this day. Here it is a vivid example of how you can go down in history simply by giving an interesting thing to the right person.

Interestingly, the method of making Dutch tears was kept secret for a long time, while at the same time they were sold as interesting toys at fairs and markets.

I read what they write about Prince Rupert. His biography is quite interesting, he was involved in a large number of historical events, but this is rather a topic for a separate post.

When I finished the post, I found an interesting and relevant video on the topic, in which the whole process is shown from the beginning to the end - from the creation of a drop of Prince Rupert, to a glass explosion:

Now the topic of Prince Rupert's drop is fully disclosed and you can safely show off this knowledge in the company or even make such drops (just be careful). That's all for today, see you soon!

Batavian tears or Bologna flasks, as well as drops of Prince Rupert, are hardened drops of tempered glass with extremely durable properties. They were brought to England by Prince Rupert of the Palatinate in the middle of the 17th century. At the same time, they attracted the close attention of scientists.

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Most likely, such glass drops were known to glassblowers from time immemorial, but they attracted the attention of scientists rather late: somewhere in the middle of the 17th century. They appeared in Europe (according to various sources, in Holland, Denmark or Germany). The technology for making "tears" was kept secret, but it turned out to be very simple.

If you drop molten glass into cold water, you get a tadpole-shaped drop with a long, curved tail. At the same time, the drop has exceptional strength: its “head” can be hit with a hammer, and it will not break. But if you break the tail, the drop instantly shatters into small fragments.

The frames recorded using high-speed photography show that the “explosion” front moves drop by drop at a high speed: 1.2 km/s, which is almost 4 times higher than the speed of sound.

As a result of rapid cooling, the glass drop experiences strong internal stresses, which causes such strange properties. The outer layer of the drop cools so quickly that the glass structure does not have time to rebuild. The core is stretched, and the outer layer is compressed. Similarly, tempered glass is obtained - however, it does not have that tail, for which it is possible to break the shell so easily.