Science fiction is filled with global apocalypse scenarios—pandemics, nuclear wars, asteroids, nuclear disasters, you name it. But if this kind of thing actually happened in the real world, and you were one of that tiny band of survivors, how would you actually live in the long term? What would be the plan, after you had looted everything you could? In this 85-minute lecture-slash-science-demonstration (great for an extended lunch break!), author/astrobiologist Lewis Dartnell walks us through the finer points of rebuilding the world.

Dartnell says early on: "Let's just imagine that this has happened, that the worst case scenario has occurred. There's been some kind of global catastrophe, a doomsday event, the collapse of civilization. And you've woken up in this post-apocalyptic world...what do you do now?" Long story short: you'd better know some basic science. Dartnell walks us through a bunch of realms (chemistry is a big one), and sets many things on fire (intentionally) throughout this talk.

If you've got a solid understanding of agriculture, smelting, explosives, fiber-spinning, water disinfection, first aid, and fire-making, you probably don't need this video. Everybody else? Enjoy:

Dartnell's lecture is based on his book The Knowledge: How to Rebuild Our World from Scratch. While I haven't read it yet, I just bought my copy and have been enjoying videos made by Dartnell for the book (most of which are included in the talk above).