Telescope

Telescope is a device for observing celestial objects - planets, stars, nebulae and galaxies. The name consists of two Greek words: "body" - into the distance, far and "skopeo" - I look. The first device to observe distant objects on the Earth - the telescope - was invented in the beginning of the 17th century by the Danish optician I. Lipersgey. But only Galileo turned the telescope into an astronomical device - a telescope.

Telescope is a device for observing celestial objects - planets, stars, nebulae and galaxies

The best of Galileo telescopes gave an increase of only 30 times, it was enough to see the mountains at Moon, open the satellites Jupiter, to see a lot of stars that are not visible to the naked eye. Modern can magnify the image thousands of times. And you can look at their help so far that even light will take 5 billion years to come from there to us. The glory of A. Eiffel (1832-1923), who built the famous tower in Paris, woke the vanity of French astronomers, who conceived the idea of creating an all-time telescope whose length would be equal to the height of the tower - 300 m! However, none of the engineers took up the design of such a giant. Then astronomers reduced the telescope's length first by half, and then three quarters. Only after this, a group of designers undertook to design a 70-meter telescope. But after the first estimates, the engineers were convinced that the mechanism for changing the tilt angles of the giant telescope turned out to be extremely cumbersome and fabulously expensive, and the case of the device itself was very complex in design. Then the idea was born to put the telescope on the ground, and to direct light from the stars and planets into the lens with the help of a siderostat - a flat mirror turned by an accurate clockwork mechanism. And indeed, the idea justified itself - the siderostat was successfully demonstrated at the World Exhibition in Paris in 1900. As for the device, after the exhibition the siderostat was mounted with a telescope tube, located horizontally in the basement of one of the old castles. Because of the limited space, its length was reduced to 60 m. But, alas, the construction did not lead to any serious astronomical discoveries and was soon dismantled for scrap.

There are telescopes for all ranges of the electromagnetic spectrum: optical telescopes, radio telescopes, X-ray telescopes, gamma telescopes. In addition, neutrino detectors are often called neutrino telescopes. Also, telescopes can be called gravitational waves detectors. In addition, optical telescopic systems are used in optics for various auxiliary purposes: for example, to change the divergence of laser radiation.

Earth atmosphere well misses the radiation in the optical (0,3-0,6 mkm), near infrared (0,6-2 mkm) and radio (1 mm - 30 m) ranges. However, as the wavelength is reduced, the transparency of the atmosphere is greatly reduced, as a result of which observations in the ultraviolet, X-ray and gamma ranges become possible only from outer space. In the optical range, the atmosphere is transparent, however, due to Rayleigh scattering, it transmits light of different frequencies in different ways, which leads to a distortion of the spectrum of the stars (the spectrum shifts toward red). In addition, the atmosphere is always heterogeneous, there are always currents (winds) in it, which leads to image distortion. Therefore, the resolution of terrestrial telescopes is limited to approximately one angular second, regardless of the aperture of the telescope.

This problem can be partly solved by lifting the telescope to a higher altitude, where the atmosphere is more sparse - to the mountains, to the air on airplanes or stratospheric balloons. But the greatest results are achieved with the removal of telescopes into space. Outside the atmosphere, distortions are completely absent, so the maximum theoretical resolution of the telescope is determined only by the diffraction limit.

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