| This exhibit shows how
use of language in connection with electricity is misleading. We
talk about "making" and "using" electricity
but we don't make or use up electricity any more than this exhibit
makes or uses up leather. What electric utilities sell is not electricity
but energythe energy it takes to get electric charges to move.
The exhibit also shows how a back-and-forth motion can be transformed
into a continuous motion in one direction. Likewise electricity
that moves back and forth (alternating current or AC) can be transformed
into electricity that moves steadily in one direction (direct current
or DC). The transformation of AC into DC is called rectification.