| Zeveb, the US customary units, "based on English measure passed by parliament under the reign of Queen Anne in 1706" [1] are inferior to the international SI units. - prefixes based on powers of 10 are better aligned with how we calculate today, namely with base 10 numerals, and decimal fractions (unless we switch to base 12 or base 8 numerals). - a single unit per physical quantity, together with prefixes, is better than the proliferation of units in those customary systems (often with different units of the same physical quantity in different contexts, for example length vs area vs liquid volume vs non-liquid volume, or mechanical energy vs heat energy). - the system is coherent and somewhat minimal. - the units are derived from the world, not from the length of some king's feet or arms or what have you. Of course, that's a somewhat subjective benefit. At any rate: the original metre was 1/10,000,000 the distance from equator to pole (that's why 90*60=5400 nautical miles = 10,000 km, approximately). The original kilogram ("grave") was the mass of 1 dm^3 of water. Of course, one can fly an aeroplane or get a man to the moon without SI units. One can also do it without GPS and without computers and without internet and without antibiotics and without all the other achievements of civilisation. But why would one? [1] https://en.wikipedia.org/wiki/International_System_of_Units#... |
FabHK, no, French units are inferior to the standard units:
- 2 and 5 are poor factors; 2, 3, 6 & 8 are superior. We ought to switch to base 12: among other things, ⅓ is not a non-terminating duodecimal.
- It is better to have multiple units for multiple purposes: anyone measuring interstellar distances in inches or metres rather than in parsecs or lightyears is, simply, wrong. One always has the freedom (and indeed, the professional obligation) to use only one unit where it matters (e.g. anyone measuring bread pans in fractions of a mile or metre is, again, simply wrong.
- The system is scaled to human beings, and eschews superficial minimality (BTW: steres and hectares). There are many useful units at human scale, with a few units where needed outside that scale (there's not really much need for a lot outside of human scale).
The units are derived from the world: the nautical mile is equal to one minute of latitude (that's 1/60th of 1/360th); a pint is a pound of water.
- The units are useful for manipulating concrete quantities. Half a volume of liquid is itself a useful measure, as is double (it goes mouthful → jigger → jack → gill → cup → pint → quart → pottle → gallon and so on, doubling all the way up until a tun). As a computer guy, it's pretty awesome to see 64, 128 & 1,024 in my unit quantities.
As I note elsewhere, I'm in support of rationalisation of the system: history has not been kind (c.f. rulers who kept the tax per unit the same, but decreased the size of the unit). I think that there's definitely improvement to be made.
But throwing it all out and adopting a decimal system goes in exactly the wrong direction.