3 ms·

Cassini, Rømer, and the velocity of light (2008)

• mrkibo 10y ago
  This is an interesting article about later additions to the quest to measure light's speed: https://www.physicsforums.com/insights/speed-light-galilean-relativity https://www.physicsforums.com/insights/speed-light-galilean-...
• Aelinsaar 10y ago
  I so rarely get to learn new words that I've never once encountered before, but this piece had one. "Prostapheresis" Apparently it's an archaic trigonometric method for approximate multiplication and division.
  • Someone 10y ago
    https://en.m.wikipedia.org/wiki/Prosthaphaeresis https://en.m.wikipedia.org/wiki/Prosthaphaeresis
    • Aelinsaar 10y ago
      That was a genuinely enjoyable read, thanks.
    • goldenkey 10y ago
      As a mathematician who is still in the learning phase and intuition is lacking, thank you. This method is ingenius and makes the invention of logarithms make even more sense consequentally. HN rocks :-)
• unixhero 10y ago
  History of radio astronomy. It can't get much better than that.