Article ID: CBB542578537

Bi-Daily Venus in the Medieval Thought of William of Conches: Explaining an Uncommon Celestial Event by Circumsolarity (2020)

unapi

Bi-Daily Venus (BDV) is an uncommon event, occurring when an observer can view that planet twice in a single day – in the twilight of dawn and dusk. That William of Conches knew of this phenomenon in twelfth-century France is surprising given the dearth of BDV accounts. Yet following unnamed sources, he discussed BDV in three of his works: Philosophia Mundi, Glosae Super Boetium, and Dragmaticon. From the appearance of the first of these volumes (ca. 1125) to the last (ca. 1145), William’s reasoning for BDV’s occurrence changed from mild scepticism of given explanations to acceptance of Venus’s sometimes circumsolar height above the sun as the correct interpretation. This paper examines William’s evolving BDV discussions, considers what planetary height meant to William, presents an explanatory diagram, and concludes that William understood Venus to be within the ecliptic plane when BDV occurs – in contrast to our modern explanation for BDV.

...More
Citation URI
https://data.isiscb.org/isis/citation/CBB542578537/

Similar Citations

Chapter Obrist, Barbara; (2011)
Guillaume de Conches: cosmologie, physique di ciel et astronomie. Textes et Images (/isis/citation/CBB001252665/)

Chapter Jaquart, Danielle; (2011)
Les emprunts de Guillaume de Conches aux théories médicales (/isis/citation/CBB001252663/)

Chapter Caiazzo, Irene; (2011)
The Four Elements in the Work of William of Conches (/isis/citation/CBB001252661/)

Chapter Lemay, Helen Rodnite; (2011)
The Science of the Stars in William of Conches' Glosae Super Macrobium (/isis/citation/CBB001252666/)

Chapter Jeauneau, Édouard; (2011)
Quand un médecin commente Juvénal (/isis/citation/CBB001252664/)

Book Obrist, Barbara; Caiazzo, Irene; (2011)
Guillaume de Conches: philosophie et science au XIIe siècle (/isis/citation/CBB001252410/)

Article Sir Paul T. Callaghan; Rebecca K. Priestley; (2012)
Reflections on this Special Issue (/isis/citation/CBB207456642/)

Article Teije de Jong; (2019)
A Study of Babylonian Planetary Theory II. The Planet Venus (/isis/citation/CBB591267076/)

Article Obrist, Barbara; (2009)
William of Conches, Māshā'Allāh, and Twelfth-Century Cosmology (/isis/citation/CBB001200452/)

Chapter Fredborg, Karin Margareta; (2011)
William of Conhes and His Grammar (/isis/citation/CBB001252671/)

Chapter Brumberg-Chaumont, Julie; (2011)
Grammaire et logique du nom d'aprè les Gloses sur Priscien de Guillaume de Conches (/isis/citation/CBB001252672/)

Chapter Burnett, Charles; (2011)
William of Conches and Adelard of Bath (/isis/citation/CBB001252662/)

Book Sajjad Nikfahm; Fateme Savadi; (2020)
Naṣīr al-Dīn Muḥammad al-Ṭūsī al-Risāla al-Muʿīniyya (al-Risāla al-Mughniya) and its Supplement (/isis/citation/CBB011433309/)

Article Bernard R. Goldstein; José Chabás; (2023)
Joseph Ibn Waqār and the treatment of retrograde motion in the middle ages (/isis/citation/CBB458115218/)

Article Kosso, Peter; (2013)
Void Points, Rosettes, and a Brief History of Planetary Astronomy (/isis/citation/CBB001320578/)

Authors & Contributors
Obrist, Barbara
Caiazzo, Irene
Sir Paul T. Callaghan
Bohloul, Hamid
Savadi, Fatemeh
Nikfahm Khubravan, Sajjad
Concepts
Astronomy
Orbits; planets
Natural philosophy
Philosophy
Cosmology
Venus
Time Periods
Medieval
12th century
11th century
Ancient
Early modern
Renaissance
Places
France
Córdoba (Spain)
Middle and Near East
Italy
Persia (Iran)
Mesopotamia
Comments

Be the first to comment!

{{ comment.created_by.username }} on {{ comment.created_on | date:'medium' }}

Log in or register to comment