There are some 14 billion incandescent light bulbs in use around the world.  Now, suppose these fixtures-in street lamps, homes, cars, stores, etc-were converted to LEDs, which can turn on and off faster than the human eye can detect.  That switching could be used to transmit digital data, thereby increasing the electromagnetic transmission capacity by more than 10,000 times.  Harald Haas, at the University of Edinburgh, proposed that this means, which he calls light fidelity or “Li-fi,” could provide communications for a variety of things from automobile headlights and traffic signals to medical devices and robots.  Watch the video in this piece-the ultimate of Debby Boone’s version of “You Light Up My Life.”   MORE with video