RussellMc wrote:

>> http://en.wikipedia.org/wiki/Mars_Climate_Orbiter
>=20
> Aye:=20
>=20
> The MCO MIB has determined that the root cause for the loss of the
> MCO spacecraft was the failure to use metric units in the coding of a
> ground software file, =93Small Forces,=94 used in trajectory models.
> Specifically, thruster performance data in English units instead of
> metric units was used in the software application code titled
> SM_FORCES (small forces).=20

IMO the biggest problem with the use of traditional (not only English or
US) units is the tendency of people who use them to work with "magic
formulas" and not use proper units with their calculations -- mostly
because they are so used to use those "magic formulas". The idea that
when executing a calculation the units must match (and that therefore
carrying the units along is a quite useful sanity check for the formula)
is something built into SI-like unit systems that is lacking from the
traditional systems.

Gerhard

--=20
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