Refracting telescope
Telescopio refractor
- Date
- 1608 · confidence high
- Place
- Middelburg, Netherlands
- Credited to
- Hans Lippershey (patent application, 1608); improved by Galileo (1609) and Kepler (1611)
- People
- 👤 Hans Lippershay1570–1619👤 Johannes Kepler1571–1630
- Field
- Communication
⚠️ Disputed: the sources disagree.
What it is
A tube with a converging objective lens and an eyepiece that brings distant objects closer; Galileo took it to 20x magnification and turned it on the sky, discovering the moons of Jupiter and the phases of Venus. A foundational instrument of the Scientific Revolution.
Zacharias Janssen (Middelburg) and Jacob Metius (Alkmaar) claimed the invention in 1608; the States General refused a patent, considering it too easy to copy. Galileo did not invent it, but he perfected it and put it to scientific use.
What it led to
- Observational astronomy and the confirmation of heliocentrism
- The Galileo-Church conflict and the debate over scientific authority
- The military and nautical use of the spyglass
- Optics as a science (Kepler, Descartes, Newton)
Built on
- Convex lens / reading stonec. 1021
- Controlled experimental method (Alhazen)c. 1021
- Eyeglassesc. 1286
- Concave spectacles for myopiac. 1450
- Spectacle lenses
- High-quality Venetian glass
- Lens grinding and polishing
Made possible
- Lunar mountains and craters1609
- Galilean moons1610
- Sunspots and solar rotation1611
- Keplerian telescope with two convex lenses1611
- Compound microscopec. 1590-1625
- Yuanjing shuo: first Chinese treatise on the telescope1626
- Screw micrometer1638-1640
- Marcgrave's astronomical observatory at Recife1639-1643
- Selenographia: first detailed atlas of the Moon1647
- Magic lantern1659
- Newtonian reflecting telescope1668
- Sigüenza's Philosophical Manifesto against Comets and Libra astronómica1680-1690
- Achromatic lens1733 (Hall) / 1758 (Dollond)
- French Geodesic Mission to the Equator1735-1744
- Discovery of Sirius B1862
- Deimos (moon of Mars)1877
- Discovery of Phobos1877
- Uranometría Argentina and Gould Belt1871-1879
- Porro-prism binoculars1854 / 1894
- Submarine periscope1901-1902
- Discovery of Charon1978