The air around you is full of information-bearing radiation—cell signals, Wi-Fi, broadcast television, AM and FM radio, GPS, and radar. They all travel as electromagnetic waves. Image via NASAThe electromagnetic spectrum/NASA. The only thing that separates one type of wave from another is its frequency—how many times the wave wiggles each second. Visible light is the same kind of wave. It oscillates trillions of times a second. Managing that range of frequencies, the electromagnetic spectrum, was the subject of a recent Mind Matters News conversation hosted by Robert J. Marks. Marks is joined by three colleagues from Baylor University’s SMART Hub, a 15-university research center devoted to enabling a more effective use of the wireless spectrum: Charles Baylis, a professor and the center’s director, who has testified before Congress on the topic; Austin Egbert, also a professor at Baylor; and Jonathan Swindell, a PhD candidate. Their shared warning is simple. The world is running out of usable frequencies, and regulation alone will not fix it. Why are we running out of usable frequencies? Charles Baylis, …