An eye for an i #314 Children

When Lippershey demonstrated a telescope

Have you peered skywards using a telescope? An optical instrument used for viewing objects, telescopes bring distant stars, worlds and even galaxies nearby by magnifying them, achieving it through an arrangement of lenses, curved mirrors and various other devices. While it primarily began with gathering and focussing light, it has now extended to electromagnetic radiation as well.

For a device that has now been in existence for over four centuries and occupies a prominent pride of place in astronomy, the answer to who invented the telescope remains murked in mystery. Given that the late 16th century saw huge strides being made with respect to the techniques employed in lens-grinding and glassmaking, it was only a matter of time before someone held up two lenses together and found out the magic they could perform.

Lippershey gets the credit

More often than not, the invention of the telescope is credited to Hans Lippershey, a Dutch spectacle maker. Legend has it that Lippershey got the inspiration for his design when he observed two children playing in his shop, holding up two lenses such that it made a distant weathervane appear nearby. Another version suggests that Lippershey hit upon the idea when he noticed one of his assistants lining up lenses by chance.

By figuring out an optimum distance at which to place the lenses and mounting them in a tube, Lippershey invented the telescope. He liked what he saw with it, and applied for a patent.

He also conducted a demonstration with his prototype – the first optical refracting telescope – on October 2, 1608.

Two others involved

But within weeks, two other Dutchmen – Zacharias Janssen and Jacob Metius – threw their hats into the ring. Janssen, also an eyeglass maker, lived in the same town as Lippershey. Both men were working with optical instruments and there is no hard evidence to refute the claim that they had developed it independently. When Metius, an expert at grinding lenses, applied for his telescope patent weeks within Lippershey’s application, the government of Netherlands ruled that no patent should be granted.

The reasoning behind this decision was that the device was easy to copy and so many people already knew about it. While Metius ended up with a small reward, Lippershey was handed a more handsome fee and with a request to produce more telescopes, appreciated for their military value.

Galileo’s role

The importance of telescope in the field of astronomy, for which it is now used primarily, was soon recognised by some. But it was Italian Galileo Galilei who majorly popularised the usage of telescope for the same.

When Galileo got wind of the device in 1609, he promptly set about making his own version of the same. Once he had done that and improved upon it for good measure, he tilted it skywards.

He observed craters in the moon, discovered four of Jupiter’s moons and provided clinching evidence for the heliocentric model (Sun as the centre of solar system) as opposed to geocentrism (all celestial bodies orbit around Earth). Astronomical changes were just around the corner.

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Before it became “telescope”

When Lippershey applied for a patent for his instrument, he called it kijker, which means looker.

Galileo, who changed the world of astronomy by observing with his version of this instrument, had used the term perspicillum to refer to it.

The name telescope is believed to have been coined by Giovanni Demisiani, a Greek poet and theologian, at a banquet honouring Galileo, during which he presented his device.

Telescope comes from the Greek words tele meaning ‘far’ and skopein meaning ‘to look, to see’. Effectively, telescope conveys the meaning “farseeing”.

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Printable version | May 6, 2021 2:23:21 PM | https://www.thehindu.com/children/when-lippershey-demonstrated-a-telescope/article25005766.ece

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