Daily Medieval

The Annals of Clonmacnoise have an entry for 670 that reads "The Moone was turned into a sanguine collor this year." A red moon u...

Despite the potentially reputation-damaging error in calculation made by al-Farghani in the case of a canal, he is better known for other a...

While expanding the urban settlements along the Tigris, the 9th century Abbasid caliph al-Mutawakkil needed a canal to bring water to a ne...

The "wooden terrestrial spheres" mentioned here are what we now call "armillary spheres." An armillary is a spherical a...

Abu Yūsuf Yaʻqūb ibn ʼIsḥāq aṣ-Ṣabbāḥ al-Kindī (801-873CE) is called the Father of Arab philosophy. Born in Kufa and educated in Baghdad, he...

[ source ] Eclipses were a mystery for awhile, but eventually enough took place that astronomers could spot the patterns. European astr...

The Ulugh Beg Observatory Museum, built in 1970 Ulugh Beg is the more familiar name of Mīrzā Muhammad Tāraghay bin Shāhrukh (22 March 1...

The Dominicans have been mentioned many times, and their founder has been mentioned as a friend of Simon de Montfort, but his life deser...

Halley's Comet on the Bayeaux Tapestry The nice thing about astronomy is that some celestial events are so predictably cyclical that...

MS. Marsh 144, fol. 135v, Bodleian The contributions of the Muslim world to astronomy are many, and I have only briefly touched on some ...

Woodcut showing meteorite coming to Ensisheim. Today is the anniversary of the first meteorite the exact date of whose fall to Earth has...

Diagram of an eclipse from a modern translation of Hipparchus It is not always easy to figure out dates from classical or medieval writi...

Nicholas Oresme (c.1325-1382) likely came from humble beginnings; we assume this because he attended the College of Navarre, a royally fu...

Image from Adelard's translation of Euclid's Elements of Geometry Being inquisitive is the first step to learning.* In the early...

Expositio & questiones manuscript Jean Buridan (c.1300-c.1361) was a University of Paris scholar who was not afraid to tackle some ...

As attractive as astrology was in the Middle Ages, not everyone was willing to accept the premise that it was "easy" to use it...

Abu Ma'shar, from his Introduction to Astronomy Albertus Magnus , Robert Grosseteste , Geoffrey Chaucer —well-known names from the M...

For a long time, there were two competing theories about how the eyes see—both wrong. Alhazen ibn al-Haytham Aristotle believed in w...

Hermann, with crutch & Salve Regina Hermann of Reichenau (1013-1054) was born to Count Wolverad II and his wife Hiltrud in Upper Swa...

Holy Trinity Church in Barsham, Suffolk The equinox, from Latin aequinoctium (the time of equal days and nights), the day twice each ye...