How did we measure the fastest speed there is? | The History of the Speed of Light Part I

The speed of light is 299,792,458 meters per second. That's an incredibly fast speed. But how did we even figure that out in the first place? And how do we even know it that accurately? Part 2 - Why can’t anything go faster than the speed of light? https://youtu.be/jRLNVvsxfFo My phases of the Moon necklace is from Eclectic Eccentricity, who have a great selection of space-themed jewellery: https://eclecticeccentricity.co.uk/products/roam-moon-phase-necklace?_pos=1&_sid=cd742dc82&_ss=r ------- More details on measuring the speed of light (or really, the length of a meter!) with your microwave: https://physicamechanica.wordpress.com/2013/12/04/speed-of-light-in-a-microwave/ Here are links to the papers mentioned: Rømer (1667) - https://gallica.bnf.fr/ark:/12148/bpt6k77856x.image.f39.langEN# Huygens (1677) - https://gallica.bnf.fr/ark:/12148/bpt6k77856x.image.f37.langEN Newton (1704) - https://gallica.bnf.fr/ark:/12148/bpt6k3362k.image.f235.vignettesnaviguer Bradley (1729) - https://royalsocietypublishing.org/doi/pdf/10.1098/rstl.1727.0064 Fizeau (1849) - https://onlinelibrary.wiley.com/doi/abs/10.1002/andp.18501550113 Weber & Kohlrausch (1856) - https://onlinelibrary.wiley.com/doi/epdf/10.1002/andp.18561750903 Maxwell (1864) - https://upload.wikimedia.org/wikipedia/commons/1/19/A_Dynamical_Theory_of_the_Electromagnetic_Field.pdf Essen (1950) - https://www.jstor.org/stable/pdf/98433.pdf?refreqid=excelsior%3A117b745e1aa593a54098a1332f856030 Evenson et al. (1972) - https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.29.1346 ---- 📚 "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: https://www.youtube.com/user/sixtysymbolsand Deep Sky Videos: https://www.youtube.com/user/DeepSkyVideos --- 👩🏽‍💻 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