Back in 2015, a lab at Ben-Gurion University proved two computers with zero connection between them could still talk. One ran its CPU hot in a pattern. The other read the temperature change on its built-in sensors, like Morse code made of heat. 8 bits per hour, 40 centimeters apart, no special hardware. That was one paper. The same lab spent the next decade breaking air gaps every way they could think of. They pulled data out through fan noise. Through power lines. Through the blinking hard…