Vulcan

• Vulcan was a theoretical planet proposed by Urbain Le Verrier
  • Urbain Le Verrier was studying the orbit of Mercury and discovered an anomaly that couldn't be explained by classical mechanics
    • This is similar to how Urbain Le Verrier helped discover Neptune
  • So, Le Verrier came up with a new planet as an explanation for the observations
• The theory was later disproved
  • Albert Einstein's general relativity ended up explaining the orbital observations
  • The Sun is massive for us to observe the warping of spacetime around it which effects Mercury's orbit (as opposed to the existence Vulcan)

Astronomy