9 ms·
The Maritime Approximation
- cb321 2y agoInteresting to see xkcd's Randall Munroe's live tour linked!
- justinl33 2y agohistorically, maritime navigation has always required much higher precision since a small error compounds into missing an island entirely. land-based measurements could afford to be fuzzier because you can course-correct using visible landmarks. this is also why maritime measurements standardized globally much earlier than land measurements.
- tiffanyh 2y agoThat was a super long post to just say “the ratio of mph/knots ≈ π/e … and it’s not very useful, but a cool coincidence.”
- Philpax 2y agoIt's about the journey, not the destination.
- tiffanyh 2y agoThere’s not much of a “journey” though … because both mile and knot are just arbitrary assigned measurements. ——- mile = 1,000 paces (as defined by Romans) knot = how many logs would pass by in 30 seconds. There’s no mathematical reason why their value is what it is. Unlike π and e that do.
- ianburrell 2y agoThe nautical mile came first. It is one minute of longitude or latitude at equator. The speed was measured with knots at specific lengths.
- bazzargh 2y agoThat approximation is only used in the USA, Liberia, and Myanmar tho. In the rest of the world, we use the metric maritime approximation, π * φ km = e nm