Tuesday, June 26, 2012


     Okay and now I have my coffee.  Now I've been thinking about Nicholas Sadi Carnot since my last post and what I want to say next, and I'll start it with this: the espresso maker at my place of residence/work is not only great for making bitter, black liquid; it's also good for explaining what the hell Carnot was talking about.
     It was made in Venezuela 14 years ago.  It is a simple stove top coffee maker, and it doesn't need no pumps to make coffee.  This is what it looks like in case you have no idea what I'm talking about, my dear imaginary friend: http://www.cerinicoffee.com/Bialetti-Moka-Express-Espresso-Maker.html . So you pour water into the lower portion and put it on the stove.  Then the magical elves of heat and pressure push the water up through the coffee grounds resulting in liquid caffeine.  Since my brain works the way it does, I like to stare at simple machines while I'm using them and try to piece together how they work.  When I first came across this machine I was reading Carnot's essay "The Motive Power of Heat", which explained this phenomenon.
     Now, the point:  If you increase the heat of fluid, it will expand.  Since the water exists in a rigid container, the pressure in the container will increase.  A fluid flows, therefore it will try to find a place to go.  Sometimes the fluid will make its own path by busting a wall, in the case of the espresso maker, we give a place to go.  So the heat builds and builds until the water goes up through the coffee grounds and then up through a pipe.
     My head has exploded.  In my attempt to try to explain this, I went back through my notes, books and did some further research with Google.  For the time being I must stop, but I will leave off on a final thought.  Look up Mariotte's Bottle.  It uses the exact same principle that I, some young punk with no previous training, have been trying to explain.  This has been fun though, and I look foward to doing more of this.  I'm learning a lot and I hope that through these post I can begin to pass on what I've learned.

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