[zdragnar]

The US uses the metric system in some places, but that is not to say it is "on the metric system"- after all, all road speed limit signs are still in miles per hour, as an example. Fuel is priced in dollars per gallon. Consumer goods are almost always sold in measurements of pounds, ounces or gallons. People are measured in feet, inches and pounds on their ID cards and at doctor's offices.

Metric has made almost no inroads at all in anyone's daily life here.

[gpm]

I believe their point is that a mile is defined to be exactly 1609.344 meters, a gallon is defined to be exactly 3.785411784 litres, a pound (mass) is defined to be exactly 453.59237 grams and so on. These are all just weird multiples of metric units at this point.

[zdragnar]

Eh, I seriously doubt that we will be changing the distance a mile represents if, for some bizarre reason, a meter gets redefined. Likewise, pounds and gallons and so forth. These measurements "defined in metric" is really more of a "formal conversion rate" ala converting between degrees F and C.

[Someone]

> if, for some bizarre reason, a meter gets redefined

Miles, feet and yards were tied to the meter in 1893 (https://en.wikipedia.org/wiki/Mendenhall_Order).

The meter got redefined 3 times since then (https://en.wikipedia.org/wiki/History_of_the_metre#Summary_o...)