Science & Discovery in the 15th century

40 sourced entries, 1402 CE to 1499 CE, oldest first. Also see Science & Discovery across every century or everything else in the 15th century.

• 1402February 8 – The Great Comet of 1402 is first observed by people living in the Northern Hemisphere of Earth. The comet, visible for eight days even in daylight, makes its closest approach to Earth on February 20. It is last seen on March 27.source
• 1407March 1 – Persian astronomer and mathematician Jamshid al-Kashi completes his treatise Sullam al-sama ("The Ladder of the Sky")source
• 1408December 5 – Emir Edigu of the Golden Horde reaches Moscow.source
• 1408The Yongle Encyclopedia is completed.source
• 1410The Prague Astronomical Clock (also known as Prague Orloj) is built by Mikuláš of Kadaň and Jan Šindel in Prague, the capital of the Czech Republic.source
• 1412January 29 – The "Mining Code" (Zakon o Rudnishma) is enacted in Serbia by the Despot Stefan Lazarević to regulate the extraction of minerals.source
• 1422August 22 – Use of the Spanish era dating system (which begins counting from 38 BC rather than from 1 AD, and thus refers to the year 1422 as "1460") ends as the Kingdom of Portugal, last on the Iberian peninsula to continue the style of dating, goes to Anno Domini dates.source
• 1424November – The Bourges astronomical clock, designed by Jean Fusoris, is installed in Bourges Cathedral as a gift to the town from Charles VII of France.source
• 1436The Florentine polymath Leon Battista Alberti begins writing the treatise On Painting, in which he argues for the importance of mathematical perspective, in the creation of three-dimensional vision on a two-dimensional plane. This follows the ideas of Masaccio, and his concepts of linear perspective and vanishing point in artwork.source
• 1437March 11– The nova Scorpii AD 1437 is first observed, and is seen by Korean astronomers at Seoul. It remains visible until March 25.source
• 1437May 18 (Full moon of Nayon 799 M.E.) – In Burma, King Mohnyin Thado of Ava announces that, effective March 30, 1438, the year will be recalibrated after 799 M.E. to will become 2 M.E., as part of the recommendations of his astrologers.source
• 1442The national law of Kristofers landslag is introduced in Sweden.source
• 1443January 28 – Raffaele Adorno was elected as the new Doge of the Republic of Genoa.source
• 1444The Iguvine Tablets are discovered at Gubbio, Italy.source
• 1451May 30 – (New moon (15th waning) of Nayon 813 ME) At Pegusource
• 1456June 9 – Halley's Comet makes an appearance, as noted by the humanist scholar Platina.source
• 1456The fifth Mersenne prime, 8191, is discovered.source
• 1467The first European polyalphabetic cipher is invented by Leon Battista Alberti (approximate date).source
• 1470Johann Heynlin introduces the printing press into France and prints his first book this same year.source
• 1471December 25 – The Great Comet of 1472 is first observed from Earth passing in front of the constellation of Virgo. The comet is recorded by astronomers in Korea and by the German astronomers Regiomontanus and Bernhard Walther, and will come within 6.5 million miles of Earth, the closest in recorded history that a great comet approaches. The comet is visible for 59 days, disappearing after March 1.source
• 1472January 22 – The Great Comet of 1472 passes within 0.07 astronomical units of Earth (6.507 million miles or 10.472 million km), the closest approach in recorded history for a great cometsource
• 1472March 11 – The Great Comet of 1472 is observed from the Earth for the last time as it flies away from Earth in the direction of the constellation of Cetus.source
• 1472Johannes de Sacrobosco's De sphaera mundi (written c. 1230) is first published in Ferrara, the first printed astronomical book.source
• 1472Pietro d'Abano's medical texts Conciliator differentiarum quae inter philosophos et medicos versantur and De venenis eorumque remediis (written before 1315) are first published.source
• 1473October 1 – Johannes Hennon publishes the medical treatise Commentarii in Aristotelis libros Physicorum.source
• 1473Almanach cracoviense ad annum 1474, an astronomical wall calendar, is published in Kraków, the oldest known printing in Poland.source
• 1477November 18 – William Caxton produces Earl Rivers' translation into English of Dictes or Sayengis of the Philosophres, at his press in Westminster, the first full-length book printed in England on a printing press.source
• 1477Thomas Norton (alchemist) writes Ordinall of Alchemy.source
• 1481The Aztec Calendar Stone or Sun Stone is carved.source
• 1483April 30 – Pluto moves inside Neptune's orbit until July 23, 1503, according to modern orbital calculations. At the time, neither planet has been discovered by Earth astronomers. The event of Pluto being closer to the Sun than Neptune will happen again during the period lasting from 1979 to 1999.source
• 1490Leonardo da Vinci observes capillary action, in small-bore tubes.source
• 1490Pêro da Covilhã arrives in Ethiopia.source
• 1490John Colet receives his M.A. from Magdalen College, Oxford.source
• 1491May 8 – A solar eclipse observed in Metz.source
• 1491Nicolaus Copernicus enters the University of Krakówsource
• 1492November 7 – The Ensisheim meteorite, a 127 kg lb meteorite, lands in a wheat field near the village of Ensisheim in Alsace.source
• 1494Johann Reuchlin publishes De verbo mirifico.source
• 1497Weights and Measures Act 1496, standardizing units of weight and of volume throughout England. Specifically, the smallest unit, the "sterling" is set at the weight of 32 corns of wheat, 20 sterlings are an ounce, 12 ounces are a pound. A gallon of wheat must weight 8 pounds Troy weight, and a 12-gallon bushel must weight 64 pounds.source
• 1497Ivan the Great of Russia issues his law code, the Sudebnik.source
• 1499August – Polydore Vergil completes De inventoribus rerum, the first modern history of inventions.source