we don't use leagues or furlongs. I know what a chain is because i have one, but that's specifically to measure land against a plat map. Every location in this country is based off common reference locations (there's a literal marker on the ground), with <i>only</i> chains and angles to delimit things (generally).<p>Read that last part again, because they use GPS to determine if the marker has moved, and that takes X minutes to quiesce. you can't take X*Y minutes to check each chain mark and angle.. not all land is rectilinear. we have a bit less than ten <i>million</i> km^2 of land in this country.<p>I'd reckon that maybe 1% of Americans know what a league is, as in the definition. Less for "furlong", less for "chain".<p>This is how these conversations go, usually. It's completely pointless, most of the people here will never interface with something where this matters. I'm a few decades old - 2.25 score years old, to be accurate. My wife knows what a score is, and how many feet in a mile, which i can never remember; by the by, it's about 5300 feet.<p>like Celsius, the metric measurements don't "mean" anything <i>directly</i> to a human. a meter is how fast light travels in 1/speedoflightinmeterspersecond. water boils at 100 and freezes at 0. compare to ~100F "roughly median body temperature", "roughly the length of an adult foot", and "roughly the length of the middle bone in your thumb".<p>yes, for "science" using units that convert is great, one of my favorite things to read is the Frink language unit file for that reason. Metric is <i>cute</i> and ostensibly "well-defined". great, use it.<p>you're not getting ~400,000,000 people to switch, potentially ever. The sheer cost is astronomical. a speed limit sign, <i>just the sign</i> is ~$22. The total cost of install could be from $500 to $3000. Per speed limit sign. There's at <i>least</i> 10,000 speed limit signs <i>on interstates alone</i>. [nearly] Every single mile of every single highway and interstate in the US has a reflective sign stating what mile it is - except for mile 420, i'm not sure why, that'll be missing but there will be a 419.7 mile marker. weird.<p>> In 2002, a contractor installed just over 50 miles’ worth of markers on I-78 and Routes 22 and 33 at a cost of $230,000, or about $4,500 per mile. Today, [...] $6,500 per mile, said PennDOT spokesman Ron Young.<p>and<p>> As of 2022, [...] the Interstate Highway System, which has a total length of 48,890 miles (78,680 km)<p>and that's just <i>interstates</i>. We have expressways, freeways, spurs, feeders, highways, state roads that use mile markers. Speed limit signs vary in distance, but figure 2 miles per (raelly 1 per mile since they're on both directions of travel, and usually there's 2 per direction, one on either shoulder) on nearly every commute surface. we have ~2,600,000 miles of paved roads, and a bit over 4,000,000 miles of roads, total, in the US - that's 6.437376e+6 kilometers, or 21 lightseconds in a vacuum, or 32 lightseconds in fiber optic cable. 32000ms ping, awesome.<p>Every house in the US is built with 16" on-center framing for the walls. we're not going to switch to "406.4mm on center", because our sheetrock, plywood, etc are all 48"x96".<p>every other country that switched did it 70+ years ago, has less people, or is <i>drastically</i> smaller.<p>like i said, rudely, but now politely, give it up, we're staying with our US customary units.