The first law of thermodynamics - conservation of energy

An excellent book if anyone out there still reads... it go way beyond any bio or 1 hour documentary can begin to touch on. It touches in heavily on the state of physics and the politics of science at the time.

During WW1 most armies were still on horseback when here comes some Germans rolling up in a tank, people thought the technology came from aliens or something... but it was just science, Germany was the epicenter and bastion of physics and the sciences at the time.