Interesting! I knew about the calve thing from my interest in spaceflight but I didn't know about the heart disease thing.

I know this isn't a perfect analogy, but I'm imagining like how fuel and air power the combustion in an engine, but you wouldn't want it in the oil system.

Actually in this case the wiring and electric motor are 100% efficient. Any energy lost will eventually end up as heat which you are trying to release into the room anyway.

Geology is fascinating to me and we touch on it a bit in our industry (landscape construction). We actually worked on a geologists house once and it was a cool experience. He explained that some of the mossy boulders weren't actually true granite but mostly mica.

He also informed us we shouldn't be putting barrier fabric at the bottom of our weeper pit because it will create a biofilm and slow the water from seeping into the surrounding earth (we put fabric on the walls of the pit to keep the soil from intruding into the drainage stone)