/kloc-in the 0/7th century, the technology of making glasses in the Netherlands has been superb, and the main technologies are grinding convex lenses and concave lenses. Convex and concave lenses often deal with eyes, but people never thought of using convex and concave lenses together.
/kloc-One day in the early 7th century, Cobis Herr, the owner of an optical shop in Mitterberg, the Netherlands, lined up a convex lens and a concave lens to check the quality of the ground lenses. Through the lens, he found that the tower of the church in the distance seemed to be getting closer and closer, so he stumbled upon the principle of the telescope.
Cobis hector immediately understood that this discovery was very useful. He put the lens in the proper position of the metal tube, which is the first telescope in the world. At that time, it was called "looking glass", which probably meant spying on other people's whereabouts. At that time, the Netherlands was at war with Spain, and the telescope played a role in the Jose War. The warships of the Dutch fleet are equipped with telescopes, which can detect the movements of enemy ships before they are found, so that the Dutch fleet has the initiative in the war. 1609 Holland and Spain call a truce, and the telescope decrypts it.
The news of the invention of the telescope soon spread in European countries. After learning the news, Italian scientist Galileo made one himself. The first telescope can only magnify the object three times. A month later, the second telescope he made can be magnified 8 times, and the three telescopes can be magnified 20 times. 1609 10 in June, he made a telescope with a magnification of 30 times. Two telescopes made by Galileo are now in the Museum of Science in Florence, Italy.
In essence, a telescope is just a magnified human eye. The pupil of the human eye is only six or seven millimeters in size, while the condensing area of a modern 500-centimeter telescope is about 200,000 square centimeters. Compared with the brightness of stars seen by naked eyes, its light gathering ability increases the brightness of stars by about 654.38+0.00000 times. Telescopes expand the vision of human eyes and realize the dream of human clairvoyance.
Galileo observed the night sky with a self-made telescope and found for the first time that the surface of the moon was uneven, covered with mountains and craters (some people think it was caused by meteorite impact).
Almost at the same time, the German astronomer Kepler began to study telescopes. He proposed another kind of astronomical telescope in Bending Optics. Unlike Galileo's telescope, this telescope is composed of two convex lenses, which has a wider field of vision than galileo telescope. But Kepler didn't make the telescope he introduced. Sagana made this telescope for the first time between1613 ~1617. He also made a telescope with three convex lenses according to Kepler's suggestion, and turned the inverted image of the telescope made of two convex lenses into a positive image.
Sagana made eight telescopes, one for observing the sun, and no matter which one can see sunspots with the same shape. Therefore, he dispelled many people's illusion that sunspots may be caused by dust on the lens, and proved that sunspots are really observed. When observing the sun, Sagina installed special shading glass for the mirror, but Galileo did not add this protective device, so that the huge light energy focused by the lens hurt his eyes, and finally he was almost blind.
In order to improve the accuracy of the telescope, Huygens of the Netherlands built a telescope with a tube length of nearly 6 meters in 1665 to explore Saturn's rings, and later made a telescope with a tube length of nearly 4 1 meter.
Many people took part in making telescopes, and Newton made the telescope take the first step beyond the light collector. He found that light can be broken down into bands of red, orange, yellow, green, cyan, blue and purple through a prism made of glass. Newton called it "spectrum". This is because light is deflected or "refracted" when it enters the glass from the air and exits the glass. Early telescopes using objective and eyepiece were called refractive telescopes. Even if the lens barrel is lengthened and the lens is machined accurately, the chromatic aberration cannot be eliminated.
Newton once thought that the chromatic aberration of refractive telescope was hopeless, but it turned out to be too pessimistic. 1733, an Englishman Hal made an achromatic refracting telescope. 1758, Boland in London independently developed the same telescope. He used glasses with different refractive indexes to make convex lenses to offset the colored edges they formed. Newton himself invented the reflective telescope in 1668. In this kind of telescope, he used a parabolic mirror instead of a lens to enlarge the image. At this time, all wavelengths of light are reversed in the same way, so there is no spectrum and no color difference when reflected, thus solving the color difference problem. The first reflective telescope was very small, and the mirror in the telescope was only 2.5 cm in diameter, but the profit and loss of Jupiter's satellite and Venus could be clearly seen. 1672, Newton made a larger reflecting telescope and gave it to the Royal Society, which is still kept in the library of the Royal Society.
Reflective telescopes have developed rapidly in astronomical observation.
At first, the biggest use of telescopes was to observe celestial bodies. With the help of telescopes, humans visited almost all the planets in the solar system and threw them into more distant space. It is worth mentioning that in 1857, Italian astronomer Secchi observed Mars with a telescope. He happened to find that there seems to be some connection between the "sea" and "sea" on Mars. Of course, it is difficult for his telescope to see what these lines are. Xie Ji used his imagination to think that these lines are "waterways" connecting the sea. 1877 Mars crashed, and another Italian astronomer, Sha Parelli, it was a good time to observe Mars. When he aimed his telescope at Mars, Sheikh's so-called waterway was not crooked, but straight and criss-crossed, so he also had a whim and thought it was a canal dug artificially. He published a paper entitled "You can be arrogant once a year", and it seems that he hasn't decided his thoughts yet. But his paper aroused people's yearning for Mars, and for a time, science fiction novels about Mars emerged one after another. Although this is only an episode of human understanding of Mars, human Mars fever has continued to this day.
Telescopes played an important role in the discovery of Uranus, Neptune and Pluto. 178 1 On March 3, 2008, William Herschel, a German who moved to Britain, discovered Uranus with a homemade telescope, but he was not sure. After observation and calculation by many scientists, he thought that William Herschel had discovered Uranus, the seventh planet in the solar system.
Dr Galle of Berlin Observatory discovered Neptune, the eighth planet in the solar system, with a telescope. The discovery of Pluto is similar to that of Neptune.
Nowadays, the use of telescopes is becoming more and more common, such as field observation and theater viewing ... and periscope, sight and collimator all adopt the principle of telescopes. The seemingly ordinary telescope has gone through an unusual road of invention and contains many technical connotations. The invention of the microscope is one of the greatest inventions of human beings in various periods. Before it was invented, human's concept of the world around him was limited to what the naked eye could see, or through holding a lens.
Microscope shows a brand-new world in human vision. For the first time, people saw hundreds of "new" tiny animals and plants, and all the internal structures from human body to plant fibers. Microscopes also help scientists discover new species and help doctors treat diseases. Above: This is the microscope of17th century British scientist robert hooke. It has a simple leather tube with a built-in lens and is placed on an adjustable shelf. Glass balls filled with water are used to focus light on objects.
The earliest microscope was made in Holland at the end of16th century. The inventor may be a Dutch optician named zacarias Zhan Sen, or another Dutch scientist Hans Lipper. They made a simple microscope with two lenses, but they didn't make any important observations with these instruments.
Later, two people began to use microscopes in science. The first is the Italian scientist Galileo. He described the compound eyes of insects for the first time after observing them through a microscope. The second is Antoine van Leeuwenhoek, a Dutch linen merchant (1632-1723), who learned to grind lenses by himself. For the first time, he described many tiny plants and animals invisible to the naked eye.
193 1 year, Ernst ruska invented an electron microscope, which completely changed biology. This enables scientists to observe objects as small as a millionth of a millimeter. 1986 won the Nobel Prize.