On: The Weight of the Air

[fuzzfactor]

Sizable cargoes weighed at higher altitudes might not look the same when they get to sea level due to the increased buoyancy of the more-dense air.

Without accounting for this, it might not be so easy to get good agreement no matter how many times the drivers get on or off the big rigs.

Same reason the Goodyear blimp floats, the bigger it is the more negative weight.