After death, a series of natural processes begin within the human body. The corpse cools, pales and stiffens before it begins to decompose. The stiffening of the corpse is called rigor mortis. It's viewed as macabre, creepy and unsettling, and it's been used as a plot device in crime shows, a jump scare in horror films, and a clue in movie mysteries.
But what, exactly, is this process, and why does it happen to nearly all bodies?
