“Standards for the exact length of an inch have varied in the past, but since the adoption of the international yard during the 1950s and 1960s the inch has been based on the metric system and defined as exactly 25.4 mm.”
“Standards for the exact length of an inch have varied in the past, but since the adoption of the international yard during the 1950s and 1960s the inch has been based on the metric system and defined as exactly 25.4 mm.”
I’m thinking, if we’re sharing pedantic data and the SI unit of distance is the metre, isn’t the inch technically defined as exactly 0.0254m?
To get even more pedantic…
It’s defined on how far light will travel in a vacuum in the time it takes caesium-133 to do a certain number of transitions between hyperfine ground states.
It’s cool how almost all units of measure are defined on caesium
Why is it based cesium?
It’s just very stable and consistent, iirc