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Re: [PSUBS-MAILIST] New to PSUB (measurement units)
Anyone recall this costly mistake?
[excerpt]..............snipped.................
A team of Lockheed Martin engineers sent NASA key maneuvering data for
the $125 million Mars Climate Orbiter in non-standard units, probably
since the craft was launched in 1998, according to a NASA official trying
to explain the loss of the craft.
Miscalculations due to the use of English units instead of metric units
apparently sent the craft slowly off course -- 60 miles in all -- leading
it on a suicide course through the Martian atmosphere.
http://www.space.com/missionlaunches/launches/orbiter_errorupd_093099.htm
--Steve
On Tue, 21 Oct 2003 13:27:43 -0700 (PDT) Bob Duncan
<katsurencho@yahoo.com> writes:
> I lived in Asia a long time, and the Metric system is much easier to
> use. It's just a matter of getting acustom to using it. Automobiles
> of U.S. manuf. are mixed metric and SAE. It's a headache.
> There is no real common ground in the U.S. system of measurement.
> It came from the old English. After the revoluationary war. The U.S.
> had to have their feet and inches different than British feet and
> inches. Arbitrary numbers were used to set the standard, and it's a
> complicated mess as far as i'm concerned. Then when you measure
> inches in some things it's fractions, but mechanical things are
> measured in .10 or .010 inch. What a headache, when i left my tenth
> of an inch tape measure at home, but i have my 1/16 tape measure
> here!!!
> bob
>
> David Buchner <buchner@wcta.net> wrote:
> Uh-oh, here comes the feet vs. meters topic again...
>
> On Sunday, October 19, 2003, at 07:09 PM, NeophyteSG@aol.com wrote:
> > Agreed. From an engineering calculations standpoint, I prefer
> using
> > metric though conceptually I have to convert it back to inches,
> feet,
> > pounds (or more accurately "slugs"). The numbers and units just
> > crunch easier in metric. From a practical standpoint, sometimes
> you
> > just don't have that option.
>
> I used to be a big, gung-ho, advocate of forcing a big switch to SI.
>
> You know: because it just "makes so much more sense" and is "more
> scientific." Also because it was more "PC" as in "the rest of the
> industrialized world has converted, why won't the US?" It just
> turned
> out to be impractical for me, because here everything is still sold
> and
> described in inches, feet, miles, etc.
>
> I've had a new thought on this, which seems simple and obvious now
> but
> hadn't occurred to me before. And that's that, for people who use
> math
> and measurement all the time, a system of units constitutes almost a
>
> language -- and expecting somebody to change their system just
> because
> "everyone else is using this other one," is equivalent (in a sense)
> to
> insisting that everybody should ditch the language they grew up
> with,
> and switch to Esperanto.
>
> Besides: I read a great line in a science fiction story, about being
>
> distrustful of anybody designing anything important, who would get
> hung
> up trying to divide by 12.
>
>
> Two guiding principles govern Israel Naval Commando doctrine:
>
> 1.Every defense system is vulnerable.
>
> 2.The enemy can deal with weapons and operational methods that are
> known; for that reason, naval commandos use imagination, daring and
> initiative, to create situations which cannot be anticipated.
>
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