Veritasium
The Best Test of General Relativity (by 2 Misplaced Satellites)
A launch mishap led to the best experimental confirmation of gravitational redshift.
Professor Dave Explains
History of Astronomy Part 4: Kepler's Laws and Beyond
The heliocentric model of Copernicus was extremely controversial in its time, but it wasn't the end of the story. Johannes Kepler used the data of his boss, Tycho Brahe, to further corroborate it, but also show that the planets do not...