telescope ;; history .

History of the Telescope By: Jackie Povitsky

History: The very first telescopes were believed to have began to appear around the year 1608. These early refracting telescopes consisted of a convex objective lens and a concave eyepiece and the telescope simply slid inside itself to focus. Galileo improved upon this telescope and is often credited for the invention of it. The first reflecting telescope was invented by 1616 and by 1688, Sir Isaac Newton improved upon this type of telescope. The first Radio Telescope was built by Grote Reber in 1937 and the first Gamma Ray telescope was built in 1991. X-ray telescopes, known as Wolter telescopes, have been in use in satellites since the 1940's. Ultra-violet telescopes began as early as 1962.

There are three main types of telescope – refractor, reflector, and catadioptric. The most common type of telescope is a refractor telescope. Refractors work by bending light through a primary convex lens known as the ‘objective’ lens, and forcing the redirected light rays to converge at a space known as the ‘focal point’. Refractor telescopes are great starter scopes, and are ideal for using in urban or heavily light-polluted environments.. Reflctors feature large-aperture “light buckets” or tubes that funnel light down the shaft towards a mirror, which then reflects the light into an eyepiece consisting of several different types of lenses. Reflector telescopes need lots of space and little background light, so they make ideal scopes for using in rural environments. A catadioptric telescope, also known as a ‘compound’ telescope, uses a combination of mirrors and lenses to increase the scope’s focal range and power while keeping weight, length and bulkiness to a minimum.