Specifically, this happened in 1893: https://en.m.wikipedia.org/wiki/Mendenhall_Order

The inch wasn't converted to a derived metric unit in the US until 1959. This creates an issue for precision machinery manufactured before the redefinition because the slight difference is enough to matter where allowed to accumulate.

If only some governing body had been aggressive enough to redefine NTSC 60Hz as actually 60 fps.

It was 60fps. Color required an adjustment to prevent stationary artifacts.

Right, but they should've put in the work to redo things back then so we wouldn't have to deal with stupid refresh rates now lol

Well, isn't that by definition true for any system of measurements? I mean, as long as we're talking about a simple straight-line distance in some real-dimensional space, it's going to be possible to measure that distance in meters (or yards, or whatever). Yes I know about fractal lengths, coastlines and so on.

I think the point is that the US customary units are typically used in a very different way, with fractions being way more important than in metric. See the image in this [1] article that talks about drill sizes for DIY use, for instance. You guys go like "oh no the 5/16:ths hole is too small, I'll step up to 19/64ths that should do it". Over here in metric-world we go more like "oh no the 7.9 mm drill was too small, I'll step up to 8 mm".

Again, the fact that it's easy to convert the 5/16:ths to 7.9375 mm is not the point, the point is how the decimal/metric units are used in practice.

> Well, isn't that by definition true for any system of measurements? I mean, as long as we're talking about a simple straight-line distance in some real-dimensional space, it's going to be possible to measure that distance in meters (or yards, or whatever). Yes I know about fractal lengths, coastlines and so on.

The US yard is exactly 0.9144m such a short decimal expansion is highly unlikely when selecting two random units of measurements. It is short because we defined the modern yard in terms of meters, selecting a short decimal expansion that was still "close enough" to the old definition to allow tooling to remain the same.

No. It's true because 1 inch is explicitly defined by the governing body as 2.54 cm, whereas one meter is defined as "the length of the path travelled by light in a vacuum in 1/299792458 of a second". https://en.wikipedia.org/wiki/Metre

The units of the metric system are defined by physical properties that appear to be constant throughout the universe.

The units of the US customary system are defined as some exact number of equivalent metric units.

This is meaningless. Everything is metric and nonmetric at the same time by this definition since you can always find a linear equation which let's you convert between the systems.