Math is a weird thing. We don't quite fully understand it all. And if you think adding up all natural numbers from one to infinity, you'd get this ridiculous number that's super long, you're wrong. You'll get -1/12. What trickery is this?

The idea that all sum of all natural numbers is -1/12 came all the way back in 1735. So how do you get that figure? Physicists Tony Padilla and Ed Copeland from the University of Nottingham walk through the process of getting -1/12. The video by Numberphile will kind of blow your mind away.