1608, Hans Justus Hans Liebig, a Dutch optician, accidentally discovered that two lenses could be used to see the distant scenery. Inspired by this, he made the first telescope in human history. 1609 Italian Florentine Galileo Galili Lei Faming made a 40x telescope, which is the first practical telescope put into scientific application.
After more than 400 years of development, the function of the telescope is becoming more and more powerful, and the observation distance is getting farther and farther. The first function of the telescope is to enlarge the opening angle of distant objects, so that the human eye can see the details with smaller angular distance. The second function of the telescope is to collect light beams much thicker than the pupil diameter (up to 8 mm) collected by the objective lens, so that the observer can see dim objects that he could not see before.
The basic principle of telescope:
Telescope is a visual optical instrument used to observe distant objects. It can enlarge the small opening angle of distant objects according to a certain proportion, so that they have a larger opening angle in the image space, and make the objects that were invisible or unclear to the naked eye become clear. Therefore, the telescope is an indispensable tool in astronomy and ground observation.
It is an optical system that makes the incident parallel beams pass through the objective lens and eyepiece and still exit in parallel. An instrument that collects electromagnetic waves to observe the electromagnetic radiation of distant objects is called a radio telescope. In daily life, telescopes mainly refer to optical telescopes, but in modern astronomy, astronomical telescopes include radio telescopes, X-ray telescopes and gamma-ray telescopes.