Rope jumping makes bungee jumping look completely sane and kinda cute. There's no flex: The whole "not dying" part is determined entirely by where you anchor the rope—and where you jump.Leave it to the nation who contrived Russian Roulette to come up with rope jumping. It looks totally simple and straight forward, until you just think for a second about the physics involved. If you jump straight down, you could dislocate some important part of your body, or worse, you could snap the rope and keep on falling. The key is to jump so that you swing across the...