How do self-driving cars know where to go and when to stop?
Picture a car with no one's hands on the wheel, gliding through traffic as calmly as someone humming along to the radio. It changes lanes. It slows for a jogger. It waits at a red light without a single yawn of impatience. So how does it pull this off? It can't actually SEE the world the way you do. Let's open the hood on its strange, clever way of paying attention.
First, the car needs senses — its own version of eyes and ears. Cameras watch the road like a hundred tireless eyeballs that never blink. Radar bounces radio waves off other cars to feel how far away they are. And a gadget called lidar spins around firing harmless little laser pulses, timing how long each one takes to bounce back. Together they sketch a glowing 3D map of everything nearby, dozens of times every second.
