The history of the development of electrodynamics. Magnetism
Two years ago, for postgraduate studies, he wrote a summary of the history of the development of electrodynamics. And then I remembered about him and decided to make several blog entries out of it, which is really good for him. :) However, while preparing this post from the essay, little remains in its original form, but it is even good. But then the main thing for me was to pass it, and now you can dig into all sorts of interesting books and references and supplement it with interesting facts.
When exactly the permanent magnets were discovered is unknown, but already in the V century AD magnetism was known. At least at this time, it was already known that magnetite pieces of mineral suspended on a rope, the large deposits of which were in the ancient city of Magnesia, are always oriented in the same direction. Actually, the name “Magnetizm” comes from the name of the city of Magnesia, which was located on a tributary of the Meander River. This city is often called Magnesia on Meander, because there was another city with the same name - Magnesia at Sipila. Now Magnesia on Meander is called Manissa and is in Turkey.
In China, the first magnetic compass began to be used as much in the 2nd century BC. to indicate the direction of movement in the deserts, therefore, we can say that the Chinese used magnetism even then, although for Europe the invention of the compass occurred in the 12th — 13th centuries AD (according to other information in the IX century).
')
Thales of Miletus
By this time, the magnets were used, but not really studied them. In addition, it was already known that amber is capable of attracting pieces of wool, and this was also referred to as magnetic phenomena. To the first researchers can be attributed, for example, Thales of Miletus (640/624 - 548/545 BC). He suggested that the magnet has a “soul” and declared the properties of the magnet with it. Actually, this is where his achievements in magnetism end.
Averroes
The Arabic thinker Abu al-Walid Muhammad ibn Ahmad ibn Rushd, also known as Averroes (1126 - 1198), made an interesting assumption at that time that the magnet distorted the space around it in accordance with the shape of the magnet.
In 1269, Pierre Peregrin of Maricourt published a manuscript “Treatise on Magnets,” in which he described many of the properties of a magnet. In fact, this manuscript was originally just a letter to a friend. Peregrin is not a surname, but a nickname that can be translated in modern fashion as a pilgrim, pilgrim, wanderer, traveler to holy places. Then, at the time of the Crusades, such a nickname was not difficult to obtain. Moreover, Peregrin participated in hostilities, and a treatise letter was written in the military camp of Charles of Anjou, besieging the city of Lucher.
It was Peregrin who discovered (or at least described) that there exist the poles of a magnet, and wrote that two magnets should be attracted, or, as he put it, “copulate”, opposite poles. He also spoke about the repulsion of magnets, if they are brought together to the same poles. He also noted that if a piece of magnetic ore is broken in half, then each of the fragments also has two poles. True, the word “pole” Peregrin did not use, he spoke about the places of the magnet, where “magnetic action” is especially great. In addition Peregrin with the help of magnets was going to make a perpetual motion machine.
William Gilbert
But especially a lot for the development of magnetism did William Gilbert (1540 - 1603). Moreover, he was a doctor of medicine, but he became interested in magnets after reading the Treatise on Magnets of the same Peregrin (and, possibly, because then the magnets were used as a laxative :)) and later published his work “On Magnet, Magnetic Bodies and Large Magnet - Earth ”, which accurately classified the known properties of a magnet. The most famous of his experiments was to explain the magnetism of the Earth. Hilbert made a ball of magnetic ore and investigated how the ball acts on a small iron needle. He found the similarity of the behavior of this arrow with the behavior of the arrow of the inclinator (the compass arrow rotating on the horizontal axis) near the Earth and came to the conclusion that the Earth is a giant magnet. Hilbert also suggested that the “magnetic effect pours out on each side” of the magnetic body (a concept remotely resembling the lines of force that would be discovered by Faraday in the 19th century). He discovered that when a magnet is heated above a certain temperature, its magnetic properties disappear; later this temperature (588 ° C) was named Curie point, in honor of Pierre Curie. Hilbert discovered that when a piece of iron is brought closer to one pole of a magnet, the other pole begins to attract more. This idea was patented 250 years after Hilbert's death. Here is another stone in the garden of patents, be they wrong. :) He also discovered the magnetization of iron, if it lies near a magnet.
Gilbert did a lot and discovered. But Hilbert could explain almost nothing. No, he tried to explain, but it turned out quite original. Here, for example, is how Hilbert explains the fact that when a single long magnet is cut, many short ones are formed, which have an initial direction of magnetization and tend to maintain their previous position in space. He compares a magnet with a branch of a tree:
And in general, he tried to explain magnetism with the help of the very same “soul of a magnet”, about which Thales spoke.
And it was Gilberg who first separated electricity from magnetism, and it was after this that electricity and magnetism were studied separately. And it was Hilbert who introduced the very concept of “electricity”. Under the electricity, he began to understand the attraction of a piece of amber wool. Before him, this phenomenon was considered a kind of magnetism. He tried to establish which substances are similar to amber in their electrical properties, and which are not. Here is the first ever use of the word "electric":
And the Latin word “electricus” means “Amber”. He also showed that diamonds, sapphires, rock crystal, glass, sulfur, salt, etc., can also attract wool and other small objects.
But about electricity (or rather, about electrostatics) will be next time.
Mr. Linson. Great experiments in physics. 1972
Magnesia on Meandra
V. Kartsev. Magnet for three millennia
William Gilbert
Thales of Miletus
Abu al-Walid Muhammad ibn Ahmad ibn Rushd
This post is on my blog.
Ps. Thanks for the karma, moved to "I'm smart."
Pps. Who cares, the continuation here .
Magnetism
When exactly the permanent magnets were discovered is unknown, but already in the V century AD magnetism was known. At least at this time, it was already known that magnetite pieces of mineral suspended on a rope, the large deposits of which were in the ancient city of Magnesia, are always oriented in the same direction. Actually, the name “Magnetizm” comes from the name of the city of Magnesia, which was located on a tributary of the Meander River. This city is often called Magnesia on Meander, because there was another city with the same name - Magnesia at Sipila. Now Magnesia on Meander is called Manissa and is in Turkey.
In China, the first magnetic compass began to be used as much in the 2nd century BC. to indicate the direction of movement in the deserts, therefore, we can say that the Chinese used magnetism even then, although for Europe the invention of the compass occurred in the 12th — 13th centuries AD (according to other information in the IX century).
')
Thales of Miletus
By this time, the magnets were used, but not really studied them. In addition, it was already known that amber is capable of attracting pieces of wool, and this was also referred to as magnetic phenomena. To the first researchers can be attributed, for example, Thales of Miletus (640/624 - 548/545 BC). He suggested that the magnet has a “soul” and declared the properties of the magnet with it. Actually, this is where his achievements in magnetism end.
Averroes
The Arabic thinker Abu al-Walid Muhammad ibn Ahmad ibn Rushd, also known as Averroes (1126 - 1198), made an interesting assumption at that time that the magnet distorted the space around it in accordance with the shape of the magnet.
In 1269, Pierre Peregrin of Maricourt published a manuscript “Treatise on Magnets,” in which he described many of the properties of a magnet. In fact, this manuscript was originally just a letter to a friend. Peregrin is not a surname, but a nickname that can be translated in modern fashion as a pilgrim, pilgrim, wanderer, traveler to holy places. Then, at the time of the Crusades, such a nickname was not difficult to obtain. Moreover, Peregrin participated in hostilities, and a treatise letter was written in the military camp of Charles of Anjou, besieging the city of Lucher.
It was Peregrin who discovered (or at least described) that there exist the poles of a magnet, and wrote that two magnets should be attracted, or, as he put it, “copulate”, opposite poles. He also spoke about the repulsion of magnets, if they are brought together to the same poles. He also noted that if a piece of magnetic ore is broken in half, then each of the fragments also has two poles. True, the word “pole” Peregrin did not use, he spoke about the places of the magnet, where “magnetic action” is especially great. In addition Peregrin with the help of magnets was going to make a perpetual motion machine.
William Gilbert
But especially a lot for the development of magnetism did William Gilbert (1540 - 1603). Moreover, he was a doctor of medicine, but he became interested in magnets after reading the Treatise on Magnets of the same Peregrin (and, possibly, because then the magnets were used as a laxative :)) and later published his work “On Magnet, Magnetic Bodies and Large Magnet - Earth ”, which accurately classified the known properties of a magnet. The most famous of his experiments was to explain the magnetism of the Earth. Hilbert made a ball of magnetic ore and investigated how the ball acts on a small iron needle. He found the similarity of the behavior of this arrow with the behavior of the arrow of the inclinator (the compass arrow rotating on the horizontal axis) near the Earth and came to the conclusion that the Earth is a giant magnet. Hilbert also suggested that the “magnetic effect pours out on each side” of the magnetic body (a concept remotely resembling the lines of force that would be discovered by Faraday in the 19th century). He discovered that when a magnet is heated above a certain temperature, its magnetic properties disappear; later this temperature (588 ° C) was named Curie point, in honor of Pierre Curie. Hilbert discovered that when a piece of iron is brought closer to one pole of a magnet, the other pole begins to attract more. This idea was patented 250 years after Hilbert's death. Here is another stone in the garden of patents, be they wrong. :) He also discovered the magnetization of iron, if it lies near a magnet.
Gilbert did a lot and discovered. But Hilbert could explain almost nothing. No, he tried to explain, but it turned out quite original. Here, for example, is how Hilbert explains the fact that when a single long magnet is cut, many short ones are formed, which have an initial direction of magnetization and tend to maintain their previous position in space. He compares a magnet with a branch of a tree:
“Let AB be the leafy willow knot… A is the upper part, B is the lower one, towards the root. Divided it in C. I affirm that the end A, re-inserted into B in compliance with the rules of vaccination, grows to it; in the same way, if B is inserted into A, then they are held together with each other and sprout. But if D is inserted into A or C into B, then they fight each other and never coalesce, but one end dies due to an inappropriate and inappropriate connection, as the one-way plant force now tends to be in opposite directions ... ”
And in general, he tried to explain magnetism with the help of the very same “soul of a magnet”, about which Thales spoke.
And it was Gilberg who first separated electricity from magnetism, and it was after this that electricity and magnetism were studied separately. And it was Hilbert who introduced the very concept of “electricity”. Under the electricity, he began to understand the attraction of a piece of amber wool. Before him, this phenomenon was considered a kind of magnetism. He tried to establish which substances are similar to amber in their electrical properties, and which are not. Here is the first ever use of the word "electric":
“Electric bodies are those which attract in the same way as amber” (Hilbert V. “About magnet”, chapter “Explanation of some words”).
And the Latin word “electricus” means “Amber”. He also showed that diamonds, sapphires, rock crystal, glass, sulfur, salt, etc., can also attract wool and other small objects.
But about electricity (or rather, about electrostatics) will be next time.
Links
Mr. Linson. Great experiments in physics. 1972
Magnesia on Meandra
V. Kartsev. Magnet for three millennia
William Gilbert
Thales of Miletus
Abu al-Walid Muhammad ibn Ahmad ibn Rushd
This post is on my blog.
Ps. Thanks for the karma, moved to "I'm smart."
Pps. Who cares, the continuation here .
Source: https://habr.com/ru/post/55731/
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