NaPM 20 April 2022

[dukealien]

Archimedes


The lever principle
is quickly stated: that
force pressing on one end
will lift the other in proportion to
lengths of respective arms.

In general
or philosophically
one thus trades one desideratum for
another: force applied
for distances supplied.

But force is not the only quantity
that may be traded:
it can be speed, a shorter lever arm
(such as an axle)
will turn a longer (its wheel’s rim)
much faster.

So too with ropes
and pulleys, wedges, inclined planes
and blades:
a scalpel’s handle moves its point
much smaller, more precisely.

In cameras we trade lens area
of glass for short exposure times
and given costs of making bigger ones
pay more for shorter snaps
which also could be gained with faster film
but greater graininess
worse resolution.

See, it’s all leverage:
we trade one thing we value for
another that we value more until,
as Archimedes boasted, we each move
the world in one dimension at a time.