Apocalyptic Science!

I'm no chemist, but thinking about AW has gotten me curious about how certain things could be done at the end of the world with supplies of everything running out.  Here's a neat one I was putting together this morning.

Did you ever read The Mosquito Coast?  There's a guy who makes ice with fire in a big machine he builds in the jungle.  I don't know how he did it in the book, but I think you could do it this way...

The basic idea is to make an evaporative cooling unit with ammonia as the evaporative agent and salt as the absorber.  You get a tank of ammonia and salt with a condensing tube (like a still) connected to a collecting tank.  Light a fire under the tank of ammonia and salt - the ammonia vaporizes and the vapor flows through the tube and condenses in the collecting unit.  Put water around the collecting unit and leave it overnight.  The salt will draw the ammonia back up through the tube, which will draw loads of heat out of the water and freeze it to ice.  In the morning, remove the ice and put in more water.

It's supposed to be a closed system where the ammonia can be reused over and over.  Of course, some ammonia will escape and will have to be topped up.

Where do you get the ammonia?  Fermented piss!

Anybody else have some neat apocalypse science to share?

I watched a bit of The Colony from the discovery channel.  The one I liked was that they burned wood and captured the wood-gas, funneling it into the tank of something that had an alternator.  That was then used to charge a bank of batteries which provided power to the factory building they were living in.

Oh, wow!  I didn't know about that show... it looks incredible!  Thanks for the tip, Trevis.

Here's an illustration of the icemaker.  This one uses solar energy, not fire, but in my AW there's not as much sunlight so you just have to boil the ammonia the old fashioned way.  Replace the parabolic trough collector with a firepit.

If you stick a turbine between the boiler and the condenser does it mess up the energy of the transformation or do you get free electricity out of the system?

Here's the slideshow of their 'builds' including some drawings.  The thing I'm talking about is the Gasifier.

http://dsc.discovery.com/tv/colony/survival-builds/survival-builds.html

After some more internet research, I think you could make hand-reloaded bullets for modern firearms, but you'd have to have access to sulfur, which could be difficult for some Apocalypse Worlds.  On the other hand, if you have volcanic activity or hot springs, it could be easier.  It works in my AW because there are still-operating oil rigs with mini-refineries that can extract sulfur from crude oil (and also produce gasoline and kerosene for my setting).

So it all starts with urine (naturally).  Ferment the urine for a couple months in buckets with a lot of straw in them.  Chemical salts accrete on the straw.  After months of this stinky process, take out the straw and wash it in water.  Pour the water through wood ashes, then let it evaporate and it will leave you with saltpeter.

Burn the saltpeter with sulfur in the presence of steam and then mix the result with water and you get sulfuric acid.  Put aside 2/3s of that.

Mix the remaining 1/3 of your sulfuric acid with more saltpeter and heat it and you get nitric acid.

Bathe cotton in 1/3 nitric acid and 2/3 sulfuric acid and then wash it multiple times in cold water and you get nitrocellulose (gun cotton), the primary ingredient of modern smokeless powder.  The other significant ingredient is nitroglycerin, but that's also made with sulfuric acid and nitric acid.

After that, it's just a matter of casting new bullets in molds and using some fairly common tools to fill used bullet casings with your manufactured powder and fix them to the bullets.  I'm sure it wouldn't be a totally safe process, but it's interesting that it could be done with pretty ancient processes.

As I read that explanation, I wonder when it's more sensible to make easier, cruder black powder and just muzzle-load.  There must be some economic factor that decides if fancy powder and cartridges are a going concern.

Yeah, probably, but the default setting uses modern firearms.  You don't want to be the guy with the musket in that setting, right?

True.  But the default setting stipulates that there's no shortage of fuel and bullets too.  If you're looking at realism, you're already diverging.  :)

Nonsense.  There's no shortage of fuel because it's being refined, and no shortage of bullets because they're being manufactured.  :)