Science & Technology: Who says 'metric' is scientific?Copyright © 1997-2010 All rights reserved
Proponents of the metric system always seem to trot out the argument that 'metric'
is the choice of science, and imply that the two are always linked - as though
'metric' is more accurate, and science can't be done without 'metric'. What
tosh. The two greatest scientists of all time (Darwin and Newton, if you must)
didn't use 'metric' - Newton used Paris measures! It comes as a shock to some
people to realise that that there are other ways than 'metric'...
Sadly for the 'metric' folk, the second came along long before their system.
One of the units of force in the imperial system is the Poundal - the force
needed to accelerate a 1lb mass through 1 foot per second per second.
A Pound-force is the force needed to accelerate a 1lb mass through the rate
of gravity, i.e. 32.174 feet per second per second, or , to put it another
way, is the force exerted by a 1lb weight (on earth). There are therefore
32.174 Poundals to the Pound-force. A kip is 1000 Pound-forces.
Work is defined as force x distance moved, so it comes as no suprise that
a unit of work is the foot-poundal, and the related foot-pound-force.
Another unit of work is the British thermal unit (Btu) which is the amount
of energy needed to raise 1lb of water through 1 degree F. However, just
as the calorie depends on what temperature the water is to start with, there
are different Btus depending on the temperature - eg 39F, 60F. A Therm is
The most common unit of power is the horsepower - BEWARE - there are many
different horsepowers, including 'metric' ones! The one normally encountered is
equivalent to 33,000 foot-pound-force/minute, in metric if you must, 745.7 Watts.