Monday, December 19, 2011

Tangent: all energy is fusion energy

...at some point in its life-cycle.  Check it out:
  • Solar:  Deep in the sun's core, all that gravitational pressure compresses hydrogen until it's just so energetic and dense that the protons fuse together to make a deuteron (a nucleus with proton + neutron).  Then the deuterons fuse with each other to make tritons (1 proton, 2 neutrons) or Helium-3 (2 protons, 1 neutron) and so on up the long ladder.  As it turns out, the particles like company: so at each step, as you're building bigger and bigger nuclei, you get a little bit of free energy out.  It's like the protons are getting all excited at coming together with their friends so they start throwing a hell of a party.  All those little parties heat up the sun yellow-hot and it radiates light to space - to us.  That's sunlight.  This has been going on for four and a half billion years.  
  • Wood, tomatoes, hamburger buns:  Plants are nature's solar cells: they eat light.  Unlike our solar cells that make conducting electrons, plants turn it into sugars and starches, and use it to build vitamins and proteins and cellulose.  (If plants were crystalline or metallic, they might use electricity directly: anyone good at genetic engineering?)  Eating plants, you get to metabolize all that energy; burning them, you get beautiful toasty fire.  And fire and sugar are stored sunlight - and sunlight is fusion power.  QED.
  • Coal, oil, natural gas: biomass, concentrated, heated and pressurized until made delicious to jet planes and locomotives.  Nothing new here.
  • Meat: just processed plants, buddy.  Super delicious, super inefficient.  next:
  • Wind: That's right: wind is solar power, and therefore fusion.  Weather systems are generated by temperature differentials on the globe north-south and across the terminator (excuse me, the terminator).  And what causes temperature differentials?  You guessed it!  (in the background, there).
So that's all pretty straightforward and obvious.  Here comes the tricky part.  Lets do this.
  • Nuclear Fission: Fission power is fusion power.  
Wait (says you), that's oxymoronic, you... oxymoron.  Fission is the exact OPPOSITE of fusion.  Instead of getting energy out by building up heavier atoms from light ones, you get power by breaking down super-heavy atoms, like Uranium.  

(aside: why do these both work?  Well, protons & neutrons have a limit to the size of party that they enjoy.  When the crowd in a nucleus gets too big, they don't like going into it anymore; and you have to give them energy to make them go in.  That limit is actually at Iron, element no. 26.  I guess nuclei in heavier elements are increasingly awkward.)  

But where do those super-heavy atoms come from?  They can't be made by fusion in stars, the stars fizzle when they get to iron.  No:  they're made in supernova.  When a large star runs out of fusion fuel and its core collapses, the resulting burst of energy tears apart some of those nuclei it spent so much time building and bombards the rest with their fragments.  There's so much energy that the protons and neutrons are crammed into these huge atoms like uranium, where they all stare at each other and have long pauses in the conversation.  

So it's fusion that puts all the energy in these radioactive heavy atoms, and that you release in a fission reactor.  Bam.

I think there's a few more:
  • Geothermal: The earth is heated by radioactive decay of heavy atoms.  See above.
  • Monkeys on bicycles: powered by bananas, powered by sunlight, powered by fusion.
  • Magic (literature): powered by the minds of authors, powered by food, etc.
  • Magic (real-world): powered by cold fusion. 

  • Tidal:  ...
Okay, you got me.  The tides aren't fusion-powered.  Tidal energy is powered by the rotation of the Earth, and the orbit of the moon, and those come from the interstellar dust spinning more in one direction than the other when the solar system was formed, which is pretty much just random chance.  Fun fact, though: if you use tidal energy to generate electricity, you are slowly making the day longer.

So what lesson can we take from all this?  Just one: nucleons are hipsters.

They want to maximize Irony.

And I'm done.

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