The device, which costs about $40,000, is called a spectrum analyzer. And for years Dooley, a consultant and self-appointed expert who left college after a year, has been measuring and recording wireless data traffic—the billions of transmissions that travel back and forth from smartphones and laptops to cell towers, routers, and other Internet connections. If you’re checking Facebook on your iPhone and Dooley is nearby, his machine will see it and light up. And if hordes of people are posting pictures to Instagram and streaming Netflix videos all around him, the display on Dooley’s machine will turn bright red. Dooley takes the readings to track which parts of the electromagnetic spectrum—the frequencies that carry everything from radio signals to X-rays—are degrading from overuse. He likes to think of himself as a “21st-century version of a land surveyor.” ... What Dooley’s machine is telling him now is this: Wi-Fi is headed for a collapse. The preferred Internet connection for most users is quickly becoming overcrowded, he argues, and could soon be overwhelmed. ... According to Cisco, the amount of data transmitted via Wi-Fi is projected to nearly triple in the next four years. The problem, says Dooley, is that the signals from all our wired devices are increasingly beginning to bump into one another, causing performance to suffer. ... a growing chorus of critics say that Globalstar’s warnings about a Wi-Fi apocalypse are completely unfounded—and that its plan, rather than fixing spectrum congestion, would actually make the situation much worse.