When Einstein proposed his new theory of gravity in 1915 - his theory of General Relativity that massive objects curve space - he came up with three ways of testing his theory. One of those ways was whether it could properly predict the orbit of Mercury, which up until then, no theory of gravity had been able to do. So why is Mercury's orbit so odd? Measuring the speed of light with marshmallows in a microwave: https://physicamechanica.wordpress.com/2013/12/04/speed-of-light-in-a-microwave/ Galle (1846) - http://articles.adsabs.harvard.edu/pdf/1846MNRAS...7..153G Le Verrier (1859) - http://articles.adsabs.harvard.edu/pdf/1859AnPar...5....1L Swift (1878) - http://articles.adsabs.harvard.edu/pdf/1878Obs.....2..161S Einstein (1915) - https://www.kritik-relativitaetstheorie.de/Anhaenge/Einstein-Perihelbewegung-Merkur.pdf Schwarzschild (1916) - http://articles.adsabs.harvard.edu/pdf/1916AbhKP1916..189S ---- 📚 "Space: 10 Things You Should Know": http://bit.ly/SpaceDrBecky 📚 US & Canada version: "Space at the speed of light" (same book, different title): https://www.penguinrandomhouse.com/books/635406/space-at-the-speed-of-light-by-dr-becky-smethurst/ 📚 German translation "Das kleine Buch vom großen Knall" : https://www.dtv.de/buch/becky-smethurst-das-kleine-buch-vom-grossen-knall-28254/ --- 🔭 Royal Astronomical Society podcast that I’m co-hosting 😱 🥳- podfollow.com/supermassive --- 🔔 Don't forget to subscribe and click the little bell icon to be notified when I post a new video! --- 📹 Dr. Becky also presents videos on Sixty Symbols: null Deep Sky Videos: null --- 👩🏽‍💻 Dr Becky Smethurst is an astrophysicist researching galaxies and supermassive black holes at Christ Church at the University of Oxford. http://drbecky.uk.com/ https://rebeccasmethurst.co.uk/