the.com/bicycles
the most energy-efficient machine humans have ever built, and it runs on snacks.
means a two-wheeled, pedal-powered vehicle that turns human effort into motion more efficiently than any animal or engine of comparable weight.
from from french bicyclette, stitched from bi- (two) and kyklos (wheel), popularized in the 1860s once someone finally figured out pedals belonged on the front wheel, not a separate crank contraption.
efficiency recordcyclists beat every animal in calories per mile
early nicknamevelocipede, meaning fast foot
penny farthing eragiant wheel made braking basically optional
global fleetover a billion bikes exist worldwide today