The history of the discovery of magnifying devices. The device of magnifying devices

How well do you know magnifying devices? 5th grade of secondary school is the time when we first get to know them. At lessons, children are told the most basic thing about their device and creators. Do not you want to deepen your knowledge about them? And maybe you are preparing a lesson on the topic "Magnifying devices" (grade 5)? In any case, we have something to tell you.

Ancient lenses

The history of the discovery of magnifying devices begins in the distant past. A large flat-convex lens has reached us - one of the oldest. Its diameter is 55 mm, and the focal length is about 150 mm. It was made of rock crystal for 2,5 thousand years BC. E. It was discovered in 1890 by G. Schliemann at the excavations of Troy. Approximately in 600-400 years. BC. E. Began to make glass lenses. They were discovered in Sargon (this is Mesopotamia). In Sweden in 1877, a double lens 5 cm in diameter was found, convex on both sides. It refers to the year 500 AD. E. It is possible to continue the list of ancient lenses, which the researchers managed to discover. The history of the discovery of magnifying devices has many facts. Despite this, how they were used in those days, one can only make assumptions.

Contribution of Roger Bacon

Modern scientists got acquainted with the detailed description of lenses, made by Roger Bacon, a monk of the Franciscan order (years of life - 1214-1294 gg.). He was a graduate of Oxford University, and also became famous as a prominent thinker and scientist. Lenses, according to his work, were used to enlarge the image. From the translation of the fragment of the work follows that Bacon managed to correctly describe the action of lenses, which served as a reverse telephoto lens (we are talking about the description of a visual one-component tube).

The Merit of Galileo Galileo

The history of the discovery of magnifying devices is inconceivable without the name of this person. Approximately 300 years after the death of Bacon Galileo Galilei, a famous scientist from Italy, created a similar pipe. It was not three-, but two-component. Practically "peer" of such a telescope is a microscope. It is considered that he owes his appearance to Galileo. Galileo opened the telescope and noticed that small objects in such a state could be increased. D. Viviani confirms that the microscope was invented by Galileo. Viviani, by the way, wrote a biography of this Italian scientist.

An important event for science was the discovery of magnifying devices in 1625. It was then that Faber, a member of the Roman Academy, first used the term "microscope" in relation to the invention made by Galileo.

What Drebel and Alkmar created, the development of Tore and Hooke

The history of the discovery of the microscope continues with the works of K. Drebel and Alkmar. These Dutch scientists designed a device that consisted of two convex lenses. Due to this, the image of the subject, which was considered under it, was presented in an inverted form. This complex microscope, which had a bifurcated or planoconvex eyepiece, as well as a biconvex lens, is considered a precursor to complex microscopes of a later time (one of them is presented in the photo below).

The Italian Tore in about 1660 made ball-shaped magnifiers from frozen glass drops. The history of the discovery of a microscope is unthinkable without this name, because the loops created by the Italian allowed to increase objects by a thousand and a half times.

Does Robert Hooke tell you something else? This English scientist made a great contribution to the discovery of magnifying devices. Robert Hooke perfected them so much that it became one of the significant events in the history of optics. The scheme of the Hooke microscope is presented in the photo below.

Thanks to this invention, in 1665, Robert managed to first see the cells on the cork slice. So, such an important science as biology has become an important technical tool. Magnifying devices continued to improve Levenguk. Let's talk about him.

Levenguk and his achievements

A significant contribution to the history of the development of magnifying devices was made by A. V. Levenguk, a Dutchman who lived in a city like Delft. Years of his life - 1632-1723. He independently designed and used in studies simple microscopes (one of the models of such devices is presented below), capable of increasing up to three hundred times.

It was Leuvenooke who first compiled a description of microscopic organisms (including unicellular bacteria), based on his observations. In 1698, Peter the Great, the Russian Tsar, paid a visit to this famous explorer. Peter was at that time in Holland and, as is known, was interested in everything new. For his Kunstkamera, which he opened in Petersburg, he purchased several complex and simple microscopes. And much later, after the opening of the Academy of Sciences, they were transferred to the disposal of this organization.

The work of Russian scientists from the Academy of Sciences

In the lesson "Magnifying devices" should also include a story about the achievements in the optics of representatives of our country. Promising Russian scientists, whose work was led by MV Lomonosov, began to use microscopes bought by Peter I in biological research. And later they actively participated in their improvement.

Opening of magnifying devices continued in 1747. It was then that L. Euler, a member of the Academy of Sciences of Petersburg (years of life - 1707-1783 gg.), Suggested using an achromatic lens for a microscope. The fundamental work of this scientist in the field of geometric optics is Dioptrika. It consists of three volumes, which were published in 1769-1771. A new microscope, already achromatic, was released in 1802, after the work of Elinus (also a member of the Academy of Sciences of Petersburg) was published.

Such a microscope at that time was considered perfect to such a degree that scientists did not even admit the idea that it could be improved. Opening it made a lot of noise at the time. The device of Elinus' magnifying devices was as follows. They were equipped with six lenses, it was possible to change the magnification smoothly, the distance from the subject to the image was changed. It was in our country that the idea of an achromatic microscope, having a variable increase, was born and embodied an important for science science. However, this idea did not take root in further developments. The change in the device's magnification by adjusting the length of the tube, however, was an important idea, which made a significant contribution to the history of the development of optical instruments. Today one of the microscopes created by Elinus can be seen at the Polytechnic Museum of Moscow, which belongs to the Institute of History, Natural Science and Technology. The photo below shows magnifying devices dating back to the 18th century.

Further improvement of microscopes

IG Tideman, a German optician from the city of Stuttgart, in the beginning of the 19th century, began to create two achromatic microscopes. University of Derpt (today it is called Tartu) has allocated him money for the work. In 1808, these devices were manufactured.

In 1807, a year before the creation of achromatic microscopes, Van Dale, a Dutch optician, published his work. In it, a description of the construction of the achromatic microscope created by him was presented. Western European historians believe that the first such device of satisfactory quality was the microscope created by this scientist. However, in all respects he was inferior to the one designed by Elinus. Incidentally, I. Fraunhofer's achromatic microscopes, issued in 1811, were distinguished by an even more imperfect construction, if compared with the microscopes of Elinus.

Russian microscopes in the 19th century

In the first half of the 19th century, magnifying devices were already produced in many places on earth. In Russia, their production began in the 18th century, but it subsided by the beginning of the 19th century. It is known that approximately in 1820 a rather high-quality microscope was produced by a workshop for the manufacture of optics, which was located at the Kazan University. However, in Russia, nevertheless, there was no rapid development of this industry, since the government of that time believed that the best option was to purchase magnifying devices abroad.

Contribution to the optics of Giambattista and Amichi

Amichi Jambattista (years of life - 1786-1863 gg.) - a well-known Italian optician, astronomer and botanist. He devoted many years of his life to the development of microscopy. In 1827, Amichi himself designed and made an achromatic lens that had an aperture of 0.60 and a good correction for aberrations. The same scientist in 1844 began experiments on the use of water and oil immersion. Thanks to them, the production of lenses with a numerical aperture of 1.30 and water immersion was started.

Abbe Microscopes

Instruments with an oil immersion having an aperture of 1.50 (which are used to this day), began to be produced thanks to the work of Ernst Abbe, the German optician. He invented the law of the sines, with the help of which the coma, observed in small linear fields, was eliminated. E. Abbe continued to develop the theory of image formation in the magnifying device. He also clarified the issue of the resolving power of these devices. Abbe was the head of the work on creating a whole series of achromatic micro-lenses of high quality. Their numerical aperture reached 1.50. These devices were manufactured in Jena by K. Zeiss (in 1872). The same company under the leadership of E. Abbe made 8 apochromates. And in 1888 its staff developed an apochromat that had an aperture of 1.60 and had a monobromonaphthalene immersion.

The last major achievements in optics

Russian scientists DS Rozhdestvensky and LI Mandel'shtam developed the theory of Ernst in their writings. An important merit of Christmas was that he introduced the concept of relative incoherence lighting. R. Richter, an employee of K. Zeiss, developed and received a patent for a special lighting device used in a microscope. However, to this day, the problem of the optimal relationship between the parameters of interchangeable lenses and the lighting system is urgent. Domestic microscopes today are in no way inferior in terms of technical performance and optical parameters to devices created by well-known companies abroad.

So, we briefly outlined the history of the emergence of modern microscopes. Developing the lesson "Magnifying devices" (Grade 5), you can use the information provided in the article.