Telescopes are instruments that aid in the observation of remote objects by collecting electromagnetic radiation (such as visible light).
The first known practical telescopes were invented in the Netherlands at the beginning of the 17th century, using glass lenses. They found use in terrestrial applications and astronomy.
Within a few decades, reflecting telescopes were invented, which used mirrors. In the 20th century many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s. The word telescope now refers to a wide range of instruments detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors.
We have compiled the development history of telescopes by the leading manufacturers.