Imagine, if you will, a world where everything from the clothes on your back to the glass in your hand was a touch-enabled device. We're not there yet, but thanks to researchers at the University of Munich and the Hasso Plattner Institute, we're closer to just such a touchy-feely future. Those German scientists are now able to tell when and where your fingertip touches (or gets close to) a wire using time domain reflectometry, or TDR. It works by sending electrical pulses through a wire and measuring the time it takes for the pules to return. See, the presence
