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The first telescope
The first person to apply for a patent for a telescope was a Dutch eyeglass maker named Hans Lippershy.
[http://www.space.com/21950-who-invented-the-telescope.html] -
Galileo's contribute
By 1610 Galileo had produced his fifth and most powerful telescope, allowing things one thousand times closer, which he instantly used and made enormous discoveries of such significance that they are hard to understand today in the context of early 17th century knowledge.
[http://longstreet.typepad.com/thesciencebookstore/2009/09/the-telescope-in-galileos-hands-the-expansion-of-the-universe-1610.html] -
Johannes Kepler's lens
In 1611, Johannes Kepler described how a telescope could be made with a convex object lens and a convex eyepiece lens.
[https://en.wikipedia.org/wiki/History_of_the_telescope] -
Issac Newton
Sir Issac Newton is credited with building the first "practical" reflector with a design that incorporated flag diagonal mirror to reflect the light to an eyepiece mounted on the side of the telescope.
[vhttps://en.wikipedia.org/wiki/History_of_the_telescope] -
The Reflector
Laurent Cassegrain in 1672 described the design of a reflector with a small convex secondary mirror to reflect light through a central hole in the main mirror.
https://en.wikipedia.org/wiki/History_of_the_telescope -
Reflector Developments
Important developments in reflecting telescopes were John Hadley's production of larger paraboloidal mirrors in 1721; the process of silvering glass mirrors introduced by Léon Foucault in 1857.
https://en.wikipedia.org/wiki/History_of_the_telescope -
Chester Moore Hall
The achromatic lens, which greatly reduces color aberrations in objective lenses and allowed for more shorter more functional telescopes, first appeared in 1733 made by Chester Moore Hall.https://en.wikipedia.org/wiki/History_of_the_telescope -
"The Great Refactors"
During the period 1850–1900, reflectors suffered from problems with speculate metal mirrors, and a considerable number of "Great Refactors" were built from 60 cm to 1 meter aperture, culminating in the Yerkes Observatory refactor in 1897; however, starting from the early 1900's a series of ever-larger reflectors with glass mirrors were built, including the Mount Wilson 60-inch, the 100-inch (2.5 meter) Hooker Telescope.
https://en.wikipedia.org/wiki/History_of_the_telescope -
The Hooker telescope and Hale Telescope
The 200 in Hooker telescope and the 5 metre Hale telescope were the next big things; essentially all major research telescopes since 1900 have been reflectors. -
The New thing
The era of radio telescopes was born with Karl Guthe Jansky's serendipitous discovery of an astronomical radio source in 1931. Many types of telescopes were developed in the 20th century for a wide range of wavelengths from radio to gamma-rays. The development of space observatories after 1960 allowed access to several bands impossible to observe from the ground, including X-rays and longer wavelength infrared bands. https://en.wikipedia.org/wiki/History_of_the_telescope
