[ricardobeat]

> A scale would tell you that you weight slightly less at the top of a mountain than at sea level, though in reality you'd have the same mass.

A pound of force uses 'standard gravity' as a constant, even though it varies across the earth. Sounds just as bad?

[ISL]

A pound of force is defined [1, 2] as 4.448222 N . No gravity necessary (but the IPK is, until the upcoming redefinition of the SI).

Yes, that definition was reached using a notion of "standard gravity", but once fixed, it is nothing but a number.

[1] https://physics.nist.gov/cuu/pdf/sp811.pdf [2] https://en.wikipedia.org/wiki/Pound_(force)

[ricardobeat]

Still not any more precise than kg to measure human weight (unless you position the human at the exact right spot on earth).

[ISL]

A properly-calibrated scale/balance will correctly determine the mass of any object in any gravitational field (gravity gradients excepted).

[WaxProlix]

Not just as bad, because you'd be measuring the correct thing, which is force. Not mass. That's all I was getting at - they're different things and depending on context, one can change (weight) where the other does not (mass). That's all.