This woman, the Marquise du Châtelet, is part of everyday life – satellite telecommunications, satellite weather images, and GPS readings. Her insights explain why energy is conserved by applying road speed limits. Her insight was that energy is proportional to the square of velocity where everyone previously thought energy was proportional to velocity. Her insight explains why it takes four times as much gas to get to 40 as it does to get to 20 and yet four times more to get to 80. It explains why it took about 3 1/2 kilotons of tricky liquids to send three men to the moon. The Marquise du Châtelet also translated Newton’s Principia Mathematica into French.