No, that’s not a typo in the title. Caloric was a kind of infinitesimally subtle fluid substance, believed by many prominent scientists in the late eighteenth century to be the source of heat when it flowed. This may sound like just another example of a now-debunked belief that many clever and educated people had in the distant past, to be put up there alongside the longstanding
"Caloric" is very similar to what we now call "thermal energy". It acts like thermal energy acts, e.g., goes from hotter to colder, so it's not surprising that Carnot and others came to correct conclusions from incorrect premises. Caloric was matter not energy, but it was "a kind of infinitesimally subtle fluid substance" that acted like thermal energy, so there was little practical difference.
What is the most interesting to me is how little science mattered for the technological advances of the Industrial Revolution. High-pressure steam engines were moving trains, ships, pumps, millstones and industrial machinery before scientists started to figure out thermodynamics, the same way people had been using yeast to ferment, brew and bake for millennia before we figured out it's a living thing.
I really enjoyed reading this, thank you for posting. I am the opposite of scientifically inclined, but it occurred to me that Carnot's premise, that heat flowed like water, begged an obvious question: if water is impelled to motion through gravity, what force would 'impel' heat to flow?
"Caloric" is very similar to what we now call "thermal energy". It acts like thermal energy acts, e.g., goes from hotter to colder, so it's not surprising that Carnot and others came to correct conclusions from incorrect premises. Caloric was matter not energy, but it was "a kind of infinitesimally subtle fluid substance" that acted like thermal energy, so there was little practical difference.
What is the most interesting to me is how little science mattered for the technological advances of the Industrial Revolution. High-pressure steam engines were moving trains, ships, pumps, millstones and industrial machinery before scientists started to figure out thermodynamics, the same way people had been using yeast to ferment, brew and bake for millennia before we figured out it's a living thing.
I really enjoyed reading this, thank you for posting. I am the opposite of scientifically inclined, but it occurred to me that Carnot's premise, that heat flowed like water, begged an obvious question: if water is impelled to motion through gravity, what force would 'impel' heat to flow?
I would have loved these pieces added throughout my physics undergrad for fun