Science & Discovery in the 13th century

24 sourced entries, 1226 CE to 1298 CE, oldest first. Also see Science & Discovery across every century or everything else in the 13th century.

• 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
• 1247Song Ci publishes the Collected Cases of Injustice Rectified, a book considered to be the first monographic work on forensic medicine.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
• 1261The earliest extant Chinese illustration of "Pascal's Triangle" is from Yang Hui's (or Qianguang's) book Xiangjie Jiuzhang Suanfa, published this year.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
• 1270Witelo translates Alhazen's 200-year-old treatise on optics, Kitab al-Manazir, from Arabic into Latin, bringing the work to European academic circles for the first time.source
• 1270The Chronicle of Melrose is ended.source
• 1272In astronomy, the recording of the Alfonsine tables is completed.source
• 1275The era of the tosafot (medieval commentators on the Talmud) ends (it began in 1100).source
• 1275Ramon Llull, Spanish scholar and theologian, establishes a school in Majorca to teach Arabic to preachers, in an attempt to aid proselytizing to Moors. He also discovers diethyl ether.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
• 1285The first record is made of an emission of life annuities, by the city of Lübeck. It is the first instance of issue of public debt in Germany, and it confirms a trend of consolidation of local public debt over north-western Europe (see 1228).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
• 1298Wang Zhen, Chinese inventor and politician, invents a wooden movable type printing (Bi Sheng invented ceramic movable type in the 11th century).source