schnurrito@discuss.tchncs.de to xkcd@lemmy.worldEnglish · 7 days agoxkcd #3023: The Maritime Approximationxkcd.comexternal-linkmessage-square8fedilinkarrow-up11arrow-down10file-text
arrow-up11arrow-down1external-linkxkcd #3023: The Maritime Approximationxkcd.comschnurrito@discuss.tchncs.de to xkcd@lemmy.worldEnglish · 7 days agomessage-square8fedilinkfile-text
It works because a nautical mile is based on a degree of latitude, and the Earth (e) is a circle. https://explainxkcd.com/3023/
minus-squarepalordrolap@fedia.iolinkfedilinkarrow-up0·7 days agoObligatory repeat of the fact that the ratio between miles and kilometres is ln(5), correct to less than 0.01% (yes, that’s a percent of a percent). The golden ratio or Fibonacci numbers are used more often for the same trick but they’re off by, at best, very slightly worse than 0.5%.
minus-squareagamemnonymous@sh.itjust.workslinkfedilinkEnglisharrow-up0·7 days agoFibonacci numbers are easier than ln(5) to calculate on the spot tho
minus-squarepalordrolap@fedia.iolinkfedilinkarrow-up0·7 days agoYou’re not wrong. The ln(5) trick is for when you have a scientific calculator but it doesn’t have the conversion built in.
Obligatory repeat of the fact that the ratio between miles and kilometres is ln(5), correct to less than 0.01% (yes, that’s a percent of a percent).
The golden ratio or Fibonacci numbers are used more often for the same trick but they’re off by, at best, very slightly worse than 0.5%.
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Fibonacci numbers are easier than ln(5) to calculate on the spot tho
You’re not wrong. The ln(5) trick is for when you have a scientific calculator but it doesn’t have the conversion built in.