1203: "The Speed of Light"
Interesting Things with JC #1203: "The Speed of Light" - In 1676, Ole Rømer made a groundbreaking discovery—proving light had a measurable speed. By observing Jupiter’s moon Io, he revealed the first true calculation of how fast light travels. This revelation defied centuries of belief and set the stage for modern physics.
Ref - American Museum of Natural History. (n.d.). Ole Rømer and the speed of light. Retrieved from https://www.amnh.org/learn-teach/curriculum-collections/cosmic-horizons-book/ole-roemer-speed-of-light