Science & Discovery in the 13th century

21 sourced entries, 1210 CE to 1296 CE, oldest first. Also see Science & Discovery across every century or everything else in the 13th century.

• 1210September 24 – Venus occults Jupiter (the last such occurrence until 1570).source
• 1226March 4 – Just before dawn, a great conjunction between Saturn and Jupiter is observed from Earth. The conjunction is more significant than other occurrences because the separation of the two planets as visible in the sky of Earth (2.1 arcminutes or 1/30th of one degree of arc) will not be closer again until March 8, 4523 CE, and the close conjunction is the most easily visible from Earth until the conjunction of December 21, 2020.source
• 1242Ibn al-Nafis, Arab polymath and writer, suggests that the right and left ventricles of the heart are separate, and describes the lesser circulation of blood.source
• 1246The perihelion of the Earth's orbit coincides with the December solstice.source
• 1247Qin Jiushao, Chinese mathematician, writes the Mathematical Treatise in Nine Sections.source
• 1249Roger Bacon publishes a major scientific work, including writings of convex lens spectacles for treating long-sightedness, and the first publication of the formula for gunpowder in the western world.source
• 1250Albertus Magnus isolates the element arsenic, as the 8th discovered metal. He also first uses the word "oriole" to describe a type of bird (most likely the golden oriole).source
• 1252In astronomy, work begins on the recording of the Alfonsine tables.source
• 1260German musical theorist Franco of Cologne publishes Ars Cantus Mensurabilis, in which he advances a new theory of musical notation, in which the length of a musical note is denoted by the shape of that note, a system still used today.source
• 1262Alfonso X of Castile ("the Wise") commissions Yehuda ben Moshe and Isaac ibn Sid to compile the Alfonsine Tables, describing the movement of the planets.source
• 1267The city of Ostrava in Moravia is first recorded.source
• 1267Roger Bacon completes his work Opus Majus and sends it to Pope Clement IV, who had requested it be written; the work contains wide-ranging discussion of mathematics, optics, alchemy, astronomy, astrology and other topics, and includes what some believe to be the first description of a magnifying glass. Bacon also completes Opus Minus, a summary of Opus Majus, later in the same year. The only source for his date of birth is his statement in the Opus Tertium, written in 1267, that "forty years have passed since I first learned the alphabet". The 1214 birth date assumes he was not being literal, and meant 40 years had passed since he matriculated at Oxford at the age of 13. If he had been literal, his birth date was more likely to have been around 1220.source
• 1269Petrus Peregrinus de Maricourt, French mathematician and writer, performs a series of experiments with magnetic poles and proposes that a machine can be run forever in perpetual motion using the properties of magnets.source
• 1270The Chronicle of Melrose is ended.source
• 1272In astronomy, the recording of the Alfonsine tables is completed.source
• 1279The second of two main surveys of the Hundred Rolls, a census seen as a follow-up to the Domesday Book completed in 1086, is begun; it lasts until 1280.source
• 1280The second of two main surveys of the Hundred Rolls, an English census seen as a follow-up to the Domesday Book (completed in 1086), is finished; it began in 1279.source
• 1280The Wolf minimum of solar activity begins.source
• 1283The Libro de los juegos, an early European treatise on board games (including chess, dice, and a version of backgammon), is commissioned by King Alfonso X of Castile ("the Wise") (approximate date).source
• 1291Guo Shoujing, Chinese engineer and astronomer, constructs the artificial Kunming Lake, which is developed into a reservoir with summer gardens for Khanbaliq (or Dadu of Yuan), Mongol capital of Emperor Kublai Khan.source
• 1296Chinese diplomat Zhou Daguan spends a year at the court of Khmer King Indravarman III at Angkor, and pens a journal setting forth his observations.source