| Telescope |
The first mentions of enlarging glass come from the year 1298. Even though the Italians found out the new ways of the glass production at the end of the 16th century, it is possible, that they also knew about the effects, created by the combination of lenses. In 1608 a Dutch producer of lenses Hans Lippershey looked through two lenses, which he held one after the other. He looked at the church tower and found out, that he had brought it near and had blew it up. Mr
. Lippershey wasn’t lazy, he let patented this invention “through which all the distant things can be seen as if they were not far off”. A telescope was created according to this invention – a bulging and a hollow lens in a tube. The enlargement: 3 or 4 times. The news about this invention were spreading all over Europe and already in the next year they appeared in France and in Italy.
But the man, who made the telescope a well known instrument, was the Italian astronomer and mathematician Galileo Galilee. He innovated the construction of telescopes step by step. At the end of the year 1609 he created (for his own astronomic research) a telescope, which enlarged 20 times! Thanks to this he was the first one, who found out, that Jupiter had its own planets and that the Sun was not only a yellow disc, and that there were some mysterious spots on it. But the picture was not of a high quality and further enlargement was insignificant.
And so Johannes Kepler later designed a telescope with two convex lenses and Christopher Scheiner constructed it according to this tracing in 1611. This construction provided a perverted picture, but it was much clearer. Kepler used it for observing the mysterious Sun sports. In contradistinction to Galilee, who became blind, he used dark glass. The telescopes of this construction were gradually innovated and grew to unusual size: Galilee’s construction was 1,5 – 2 m long, in the 70s of the 17th century Johannes Hevelius built a telescope, which was 42 m long!
The next breaking came in 1672, when an Englishman Isaac Newton experimented with prism (a glass trilateral prism) and found out, that it can break the light into separate colours. Therefore he replaced one of the lenses with a mirror. So he laid the fundaments to all later mirror telescopes used for astronomical observations.
