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.

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 :-)

That was a genuinely enjoyable read, thanks.

This is an interesting article about later additions to the quest to measure light's speed: https://www.physicsforums.com/insights/speed-light-galilean-...

History of radio astronomy. It can't get much better than that.