Let’s imagine civilisation collapses tomorrow. What knowledge would a small community of survivors need to reboot civilisation as quickly as possible?
Live off supermarket food as long as possible.
A small post-apocalyptic community won't need to relearn the basics of agriculture immediately – the huge reservoir of preserved food in supermarkets will offer a grace period before successful farming becomes a matter of life and death. An average supermarket can feed a single person for 55 years, 63 if you eat the canned cat and dog food too...
Sheng Li / Reuters / Reuters
Open a can without a can opener.
The last thing you want to do with your scavenged can of food is try to hack into it with a knife and risk slipping and cutting yourself in a world without antibiotics. But opening a can without an opener is astoundingly easy, if you just think about how a can is made. A cylinder of tin-coated steel is capped with a disk of metal by folding over the edge – so all you need to do to open a can is wear away only around a millimetre of metal in that protruding lip. Simply grind the end of the can on an area of concrete and the lid will soon pop off.
Harness fire.
You won't need to rub sticks together to ignite a fire in the immediate aftermath; even if you can't find any matches or lighters, everyday objects can be repurposed in surprising ways. For example, crack open a fire alarm to release the 9V battery, and rub the terminals against a fluff of steel wool from under any kitchen sink or abandoned supermarket. The thin wires have high electrical resistance and will heat up and burst into flame.
Make yourself a stove.
A ‘gasifier stove’ makes very efficient use of wood fuel and can be built with only simple tools and a few old tin cans. Wood is burned in the inner can, with holes at the bottom to draw air through the fuel, but importantly a second ring of holes at the top. This re-introduces oxygen and ignites the flammable vapours and gases given off by the wood as it breaks down. This gasification process can even be used to power a cars and trucks.