Early aircraft radar, for example, was practically useless; pilots ignored it. Bush made sure that pilots went back to the scientists and explained why they weren’t using it. The reason had nothing to do with the technology: pilots in the heat of battle didn’t have time to fiddle with the complicated switches on the early radar boxes. The user interface was lousy. Scientists quickly created a custom display technology—the sweeping line and moving dots now called a PPI display. Pilots started using radar.
