MacGyver me!

December 3, 2012 6:45 PM

What are some natural ingredients one might stumble upon in the wilderness that you could potentially mix together (sans laboratory) to create a flash or explosion?

For a story-- I'm not planning to blow anything up. :)

Wood ash or pine sap or animal dung (fertilizer) are all examples of the kind of combustible ingredients that could be found in the great outdoors, and that might be used to create a small flash or explosion.

What combination of natural ingredients could (however improbably) make this happen? If I have to resort to gunpowder I will, but I'd prefer to avoid it.

Thanks!

posted by np312 to Science & Nature (12 answers total)

Best answer: Sawdust thrown into a fire creates a very satisfying cloud of flame.
posted by ottereroticist at 6:54 PM on December 3, 2012

We lit last year's xmas tree. Holy shit.
posted by unSane at 7:00 PM on December 3, 2012 [2 favorites]

Best answer: If one had access to something with a really high surface area to mass ratio (like wheat or sugar dust, or nondairy creamer, for instance), a cloud of the stuff will combust in a sort of flash explosion. One occasionally hears of silo/elevator workers being killed in such accidents.
posted by mr. digits at 7:01 PM on December 3, 2012

If you decide that it fits the story, you could have your characters stumble upon an illegal moonshine still... the finished product could be exciting to combust.

If you want further dangers, a meth lab would also provide dangerous mixable chemicals.
posted by 1367 at 7:06 PM on December 3, 2012

Best answer: http://en.wikipedia.org/wiki/Phosphorus or
or
Some fertilizer or
sulfur, charcoal, and potassium nitrate = black powder
posted by blaneyphoto at 7:12 PM on December 3, 2012

Best answer: Lycopodium! I remember seeing it often in the woods while walking with my family. It might require drying, but it's the plant that they used to make flash bulbs work way back when. See the link at the bottom of the wikipedia page to simulating a grain elevator explosion.
posted by ldthomps at 7:20 PM on December 3, 2012 [7 favorites]

How improbably lucky/clever is your MacGyver character? He could, perhaps, figure out a way to utilize the will-o'-the-wisp, aka swamp gas.
posted by dephlogisticated at 9:07 PM on December 3, 2012

Best answer: With a little bit of planing and a bunch of urin you've pretty much got yourself some phosphorus.
posted by KeSetAffinityThread at 9:37 PM on December 3, 2012

Response by poster: You guys are the best. Awesome answers!
posted by np312 at 10:11 PM on December 3, 2012

Best answer: How much time does your character have to make their explosive. I've just been doing some research on this very thing (The Pirotechnia of Vannoccio Biringuccio) and Biringuccio goes into great details about extracting saltpeter and where you can find it without having to screw around with a mess of manure (along with theory on why it is found where based on a four element model of the universe).
posted by Kid Charlemagne at 4:20 AM on December 4, 2012 [1 favorite]

Best answer: You know those little bubbles that come up from the mud at the bottom of a lake when you are walking near the shore? That's methane made by bacteria in the anoxic environment of the mud. Get a bucket or something and drill a small hole in the bottom of it, then plug the hole up with something. Fill the bucket with lake water, then turn the bucket over so it's upside down while holding it in the water. Now it's more or less full of water and upside down. Lift the bottom (now the top) of the bucket out of the water a little bit and walk around the lake trying to catch as many of those little methane bubbles as you can in the bucket. The methane will displace the water and create a pocket of methane gas in the head of the bucket which will hopefully start to rise a bit out of the water. You'll need to do this for 30 minutes or so, maybe more... Once you're collected enough get a friend in the water with a lighter. Remove the plug from the bottom (now the top) of the bucket and light the lighter while slowly pushing the bucket down into the water. The pressure of pushing the bucket into the water pushes the methane out (like blowing air out of your mouth) and if you have the lighter nearby it makes a nice bit of flame. Nothing like an explosion but probably enough to burn your hair if you were leaning right over it.

Once you've started, don't take the bucket out of the water or remove the plug until you're ready or you'll lose all your methane.

I did this with my astrobiology professors in undergrad and can vouch that it works if you're willing to spend the time bent over a half submerged bucket walking around the shore of a lake.
posted by pwb503 at 4:59 AM on December 4, 2012 [1 favorite]

Best answer: I worked at my local science museum for years, and Lycopodium powder was a staple of the "Combustion" demonstration. They had a rig which used a pint-sized (literally pint-sized) paint-can rigged with an air-hose at the bottom. Demonstrator blew into the hose which blew the light moss-spores into the air, and as soon as they hit the flame positioned in the mouth of the can, they would flash-over. It gives off a distinct but not repulsive smell.
posted by Sunburnt at 8:23 AM on December 4, 2012