The Unluckiest Astronomer in History (11 Years for One Cloud)

In 1760, the French astronomer Guillaume Le Gentil sailed for India to watch Venus cross the face of the Sun, one of the rare events that could finally tell us how far away the Sun is. A war, the monsoon and a rolling ship ruined the first try. So he stayed in the Indian Ocean for eight more years, waiting for the next one. On the big morning in 1769, after weeks of perfect skies, one cloud covered the Sun for exactly as long as the transit lasted. This is his story, told from his own book: the voyages, the Tamil astronomer who calculated eclipses with cowrie shells, the hurricane, the trip home after eleven and a half years, and what he found when he got there. Plus one popular myth about him that doesn't hold up. Chapters 0:00 Cold open 0:44 A priest who looked up 1:42 Halley's challenge 3:46 The first transit 5:56 Eight more years 7:03 Pondicherry, at last 7:37 The astronomer with the shells 9:09 The fatal cloud 10:51 The way home 11:53 Back from the dead 12:32 A happy ending 13:09 Did it work? 14:18 The lesson Question for you: what's the most stubborn thing you've ever waited for? Sources: • Le Gentil, Voyage dans les mers de l'Inde, vol. 1 (1779): https://archive.org/details/gri_33125... • Michel Danino, "Le Gentil à Pondichéry : de Vénus à l'Inde", Synergies Inde 7 (2016): https://www.gerflint.fr/Base/Inde7/nu... • Linda Hall Library, Guillaume-Joseph Le Gentil: https://www.lindahall.org/about/news/... • NASA, the 2012 transit of Venus seen by SDO: https://svs.gsfc.nasa.gov/ Pictures in the notebook (public domain): Edmond Halley by Thomas Murray, c. 1690 (Wikimedia Commons); "Passage de Vénus observé en pleine mer par le Gentil", La Nature, 1874 (Wikimedia Commons); the 27 lunar constellations, from Le Gentil's Voyage dans les mers de l'Inde (BnF / Observatoire de Paris, via Wikimedia Commons); the 2012 transit of Venus (NASA/SDO). Music: soft piano bed (royalty-free, Pixabay license). Astro Bite Club: one cosmic mystery, one bite at a time. Animated in Mira's space notebook. Sky Chasers: the people who chased the sky. #astronomy #history #venus #astrobiteclub