Many of us probably take telescopes for granted. Sure we have seen them in various telescope stores, on the internet and even on the Discovery Channel. Not many of us really know the history behind one of the most important inventions for astronomers. The following is a brief history of the telescope throughout the centuries.
It is difficult to give any one person credit for having invented the telescope. We do know that around the early part of the 16th century there were a few people at least toying with the idea of building something to view the heavens in greater detail.
Galileo was the first to really strive to improve the telescope. In 1609 he created a telescope that was capable of 30x magnification, which he also used to discover the satellites of Jupiter and hills and valleys on the moon.
It wasn’t long before telescopes started being built larger and larger. Astronomer Johannes Hevelius built a telescope that was over 150 feet long. Such large telescopes required enormous contraptions to support them and were difficult to use, since even the slightest breeze made viewing an image through the scope all but impossible.
Isaac Newton is generally credited with building the first practical telescope in 1668. Previous telescope designs were rather large and not all that easy to use. His design used a small flat diagonal mirror that reflected light to an eyepiece which was mounted to the side of the telescope. This type of telescope is still referred to as a Newtonian telescope.
The invention of the achromatic lens near the end of the 16th century allowed for even smaller, more accurate telescopes to be built. The achromatic lens allowed telescopes to be built with a relatively large lens and relatively short focal length.
It wasn’t long after this that giant optical telescopes started making their appearance on the scene. The largest such telescope was displayed at the Paris 1900 Exposition. This telescope featured an objective diameter of 49.2 inches. Attempts to build larger refracting telescopes failed since larger mirrors weren’t able to support their own weight.
In more modern times the invention of adaptive optics has again improved man’s ability to peer into the heavens. An adaptive optical telescope reduces the effects of rapidly changing optical distortion caused by the motion of air currents in the Earth’s atmosphere. Essentially, an adaptive optical telescope has the ability to constantly change the shape of its mirror to compensate for these changes in the atmosphere. The first such telescopes were the Keck telescopes which were built in 1993.
The next time you head outside to gaze at the stars through your telescope or even just happen to find yourself at one of the telescope stores, remember that what many consider a toy, others have heralded as one of the greatest discoveries of man. Think of the early pioneers of telescopes such as Newton and Galileo who devoted much time and energy into what many of us take for granted today; the ability to peer far into the heavens from the comforts of Earth.
Whether you're looking for your first telescope or are ready to upgrade, you can find what you need online. Refer to our reviews of the best online telescope stores to find great telescopes and telescope accessories.
At TopTenREVIEWS We Do the Research So You Don't Have To.™