Who invented telescopes?
BEING able to reach for the stars has been made a lot easier thanks to the telescope – which allows us to see them all up close.
The telescope has seen a lot of developments since it was first invented over 400 years ago. But who invented the telescope, and why?
Who invented telescopes?
Hans Lippershey, a Dutch eyeglass maker, made the first widely distributed telescope, and applied for the first telescope patent in 1608.
Lots of inventors were working on similar designs around the same time, but Lippershey made an important observation.
He discovered that reducing the light in the telescope and focusing it meant he could see images even further away.
His original telescope could magnify up to three times.
Lippershey first showed his telescope to Prince Maurice of Nassau in September 1608.
But he was denied the patent he applied for on October 2, 1608, because other scientists and glass makers came forward with similar devices.
Another Dutch man, Jacob Metius, presented his own telescope a few weeks after Lippershey – but was also denied a patent, because of Lippershey's application.
And Zacharias Janssen, also a Dutch eyeglass maker, was another contemporary working on his own version of the telescope.
Janssen was once claimed to have got their first – but this has since been proved to be inaccurate.
Today, Lippershey generally gets credit for inventing the telescope, while Janssen is credited with creating the upright compound microscope.
Lippershey was given a government contract for the use of his design, and telescopes could be found all over Europe within six months.
Astronomer Galileo Galilei made significant modifications to Lippershey’s telescope, before making his observations of space.
Galileo’s final version could magnify up to 30 times.
The word telescope comes from the Italian "telescopio", which first appeared early in the 1600s, and first appeared in English in 1650.
Why were telescopes invented?
Telescopes were invented because of natural developments in the technology and science of magnifying lenses, and a desire to see and understand the cosmos.
Lenses for glasses existed as early as the 1400s but were not of sufficient quality for use in astronomy.
These had improved significantly by the 1600s, and glasses makers were able to polish and refine the lenses.
Lippershey made glasses in the Netherlands, and he and many others were investigating the power and potential of lenses.
At the same time, the Renaissance – a period of cultural, artistic and economic "rebirth" in Europe – was fuelling an interest in understanding and seeing other space objects.
The telescope was used to prove Copernicus' theory that the Sun was at the centre of the universe.
It also enabled the first sightings of Jupiter’s moons, and the first observations of objects orbiting others.
Galileo was first credited with these observations, but he was not the only one to gaze at the stars.
Galileo did not necessarily get there first, but he published his findings and had them distributed widely.
A Brit, Thomas Harriot, also designed a telescope, and he made more accurate observations and sketches of the moon than Galileo – but he did not publicise his work the way Galileo did.
German astronomer Simon Marius made more accurate observations of Jupiter’s moons than Galileo.
He was passed off as a faker when he tried to claim this in his lifetime, but he is widely believed now.
And another German astronomer, Christoph Scheiner, observed independently from Galileo that the Sun was not a perfect sphere, and noticed sun spots.
And another important observation made with the first telescopes was that the moon is not round, and has mountains and craters.
Previously the moon was thought to be like a pearl, or a translucent sphere.
History of the telescope
- 1608: Hans Lippershey applied to patent his telescope.
- 1609: Galileo modifies Lippershey's telescope for astronomic use.
- 1611: Johannes Kepler described an improved lens for the telescope.
- 1655: Christiaan Huygens was building a Keplerian telescope, based on Kepler's description. This used convex lens to help view distant objects.
- 1668: Isaac Newton built the first telescope with a mirror reflecting to an eye-piece on the side of the telescope – a reflector. This helps objects appear brighter through the eyepiece.
- 1672: Laurent Cassegrain improves on Newton's design, creating the achromatic lens. This helped to improve colour distortion through the eyepiece.
- 1721: John Hadley made paraboloid mirrors, which collected energy from light, sound, or radio waves.
- 1733: Chester Moor Hall built the first telescope to incorporate the chromatic lens. This meant telescopes could be made shorter, and were more accurate when it comes to colour.
- 1758: John Dollond began commercial production of telescopes based on Hall's design.
- 1855: Leon Foucault introduced the idea of silvering glass mirrors, which tested the shape of a reflector mirror to see whether or not it was perfectly spherical. This spherical shape allowed for optimal performance of the telescope.
- 1897: The Yerkes Observatory Refractor was built – home of the largest refracting telescope ever built, with a main lens that measures over one metre in diameter.
- 1900: Glass-mirror reflectors, such as the Mount Wilson, began to be built. After this, most major telescopes were reflector telescopes.
- 1910: The Ritchey-Chretien form of the Cassegrain reflector was developed, but not widely used. It gave a much wider field of view.
- 1917: The Hooker Telescope was built. This measured 2.5 metres, and was the world's largest telescope from 1917 to 1949. It was used by Edwin Hubble in 1922 to prove that the Universe extends beyond the Milky Way galaxy.
- 1931: Karl Guthe Jansky discovered an astronomical radio source that enabled the development of radio and other wave-length telescopes.
- 1948: The Hale Telescope was built, measuring over five metres. This telescope was groundbreaking, and made many important discoveries, including two moons of the Planet Uranus in 1997.
- 1960: Observatories began to be built, enabling the use of longer wave-length bands such as X-rays and infrared to be used.
- 1970: Computer-controlled telescopes at elevated positions began to be used, such as at Alt-Azimuth Mount and Active Optics.
- 1990: The Hubble Space Telescope was launched. It is 13.2 metres long and has a 4.2 metre diameter, and has made more than 1.3 million observations.
- 1993: Other large telescopes began to be manufactured, such as the Keck telescopes, up to ten metres, the ESO eight-metre telescopes, Gemini Observatory, and the Subaru Telescope.
- 2021: Nasa plans to launch the James Webb Space telescope. It is primarily for infra-red wave length, and has a five-layer shield, each layer the size of a tennis court.
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