A Middelburg spectacle-maker's refused patent application of October 1608 (1608)
Hans Lipperhey asked the States General for 30 years' protection; rival claims from Jacob Metius and Sacharias Janssen sank it
General knowledge · Inventions & discoveries
The telescope
1608
Invention — optics and astronomy
On 2 October 1608 Hans Lipperhey, a spectacle-maker of Middelburg in the Dutch Republic, applied to the States General for a patent on an instrument "for seeing things far away as if they were nearby". The patent was refused, because rivals including Jacob Metius and Sacharias Janssen claimed the same idea, but news of the device crossed Europe within months. Galileo built his own in 1609, turned it on the sky, and published the results in Sidereus Nuncius in 1610; Kepler, Newton and their successors then turned a novelty into the central instrument of astronomy.
How to spot them
- ▸Middelburg, 1608; a patent application refused because too many people claimed the idea
- ▸The Medicean stars, the phases of Venus, and a Moon with mountains, reported in 1610
- ▸Refractors bend light with lenses; reflectors gather it with a curved mirror
- ▸The name was coined at a banquet in Rome in 1611, from Greek for 'far-seeing'
Key facts
'Sidereus Nuncius', published in Venice in March 1610 (1610)
Galileo's 'Starry Messenger' reported lunar mountains, countless new stars and four moons of Jupiter
The four bodies Galileo named the Medicean stars (1610)
Io, Europa, Ganymede and Callisto, now the Galilean moons; Simon Marius claimed independent discovery and supplied the names we use
Newton's 1668 answer to chromatic aberration: a curved mirror (1668)
The first working reflector, about 15 cm long, now in the Royal Society's collection
Kepler's 1611 design swapped the concave eyepiece for a convex one (1611)
Described in Dioptrice; it gives a wider field and an upside-down image, and became the astronomical standard
Lord Rosse's 'Leviathan of Parsonstown', a 72-inch reflector of 1845 (1845)
At Birr Castle in Ireland; the largest in the world for 70 years, and the first to reveal spiral structure in nebulae
A flawed 2.4-metre mirror launched in 1990 and corrected by spacewalk in 1993 (1990)
The Hubble Space Telescope's spherical aberration, fixed by the COSTAR optics
Key ideas
- What matters is aperture: the area of the objective sets how much light is collected and how fine a detail can be resolved, which is why every generation builds bigger
- Lenses of a single glass bring different colours to different focuses, producing coloured fringes; Newton's mirror sidesteps the problem entirely, and the achromatic doublet of the 1730s tames it
Quick-fire facts
- •The word 'telescope' was coined by the Greek mathematician Giovanni Demisiani at a Roman banquet for Galileo in April 1611, hosted by the Accademia dei Lincei
- •Galileo's best instruments magnified about 30 times, with a field of view smaller than the full Moon
- •His observation of the phases of Venus in 1610 disproved the pure Ptolemaic system
- •The Yerkes Observatory's 40-inch refractor of 1897 remains the largest refracting telescope ever used for research: bigger lenses sag under their own weight
- •William Herschel discovered Uranus in 1781 with a homemade reflector, and later built a 40-foot telescope at Slough
- •The 200-inch Hale Telescope on Palomar Mountain, completed in 1948, dominated astronomy for decades
- •The James Webb Space Telescope, launched on 25 December 2021, observes in the infrared with a 6.5-metre segmented gold-coated mirror
- •Radio astronomy began with Karl Jansky in 1932; the Lovell Telescope at Jodrell Bank has been steerable since 1957
- •Very-long-baseline interferometry lets separate dishes act as one: the Event Horizon Telescope produced the first image of a black hole's shadow, in M87, in 2019
Drill it — 10 cards
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Sources
- Royal Museums Greenwich — The history of the telescope
- Massimo Bucciantini, Michele Camerota and Franco Giudice — Galileo's Telescope: A European Story