The oldest light in the universe

The Cosmic Microwave Background, leftover light from the big bang, carries a wealth of information about the universe—for those who can read it. Fifty years ago, two radio astronomers from Bell Labs discovered a faint, ever-present hum in their telescope that they couldn't identify. After ruling out radio broadcasts, radar signals, a too-warm receiver and even droppings from pigeons nesting inside the scope, they realized they'd found a soft cosmic static that originated from beyond our galaxy...