How Invention Begins ch. 6

Now we get to the part of the story where scientists try to understand how steam engines work. 
Large Corliss steam engine
There are two kinds of answers to this question:
Oxygen wasn't discovered until 1777--before that there was a completely different theory of chemistry
How science changes:
Heat isn't a substance because you can change mechanical work into heat (friction) or change heat into mechanical work (as a steam engine does)

Law of conservation of energy: energy is not created or destroyed, you can just change it from one form to another

Discovery of conservation of energy:
diagram of energy transfer
But you can't simply change one form of energy into another indefinitely
Popular restatement of the first three laws of thermodynamics: You can't win, you can't break even, you can't get out of the game.

(another science joke) The inventor of the third law of thermodynamics said:
the science of thermodynamics is a result of people trying to understand steam engines that were already working

This page written and copyright Pamela E. Mack
HIST 122
last updated 9/5/07