DARPA

Applying mild electrical currents to your head could take away pain, help memory, and improve attention—and the U.S. military is very interested.

• By Emma Young

It was a dark time in a long, drawn-out war. Afghanistan was festering with resentment. The Pentagon brass were desperate. It was the kind of last-ditch moment when authorities start throwing an era's weirdest ideas at its most hopeless bureaucratic mistakes.

• By Brian Calvert