Football is a cruel sport that permanently injures the brains of its players. A “great hit,” the kind that elicits “oohs” and leads to instant replays, is a trauma. The brain slams into the skull. Hard. At the University of North Carolina’s Sports Concussion Research Program, they put six sensors into the helmets of their players. Malcolm Gladwell reported the results for one young defensive lineman, who in a simple day of practice, sustained four hits ranging from 63 to 96 gs. To put those numbers in perspective, Gladwell writes, “if you drove your car into a wall at 25 miles per hour and you weren’t wearing your seat belt, the force of your head hitting the windshield would be around 100 gs.