Gruesome Facts About Not Wearing Seat Belts

“Did you ever notice how often the words “unrestrained passenger” turn up in Trauma: Life in the ER just before something Really Messy rolls in the door? In a collision, you have three or four sub-collisions all taking place in sequence. First, the vehicle hits some object. The vehicle abruptly slows, but unrestrained objects inside it continue at the same speed, in the same direction. Then the unrestrained body hits the interior of the vehicle, and starts to slow. That’s the second collision. That body’s internal organs are still moving at speed until they hit the inside of the chest (or get cheese-sliced by their supporting ligaments—and that’s where you get things like bisected livers or aortas). The fourth collision is when the bowling ball you left on the rear deck hits you in the back of the head, because that continued at the same speed in the same direction. Newtonian physics: Learn it, live it, love it…”

full article: Brad DeLong

(H/T Andrew Sullivan)