I really hope your default is in lbs

I'm a big fan of using units. There wasn't really anything (update: unit-self-aware) on CPAN at the time, so I wrote Math::Units::PhysicalValue, which would make the initial weight so much clearer.

use Math::Units::PhysicalValue qw(PV);

my $weight = PV "170 lb";
my $mass   = $weight + "0 kg";

print "My mass on earth at sea level is $mass.\n";
[download]

I feel obligated to point out here that your mass is not dependent on your position. :-) (Oddly enough, though, nobody seems to want to figure their weight in Newtons.)




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If God had meant us to fly, he would *never* have given us the railroads.
    --Michael Flanders

Yes, that default is definitely pounds, not stone, kilograms, ounces (avoirdupois or otherwise), or anything else. It's still too high of a default, though.