The year has been chock-full of scientific breakthroughs, but the University of Colorado is determined to finish 2015 with a bang. Its researchers have created what they say is the first full-fledged processor to transmit data using light instead of electricity. The design isn't entirely photonic, but its 850 optical input/output elements give it the kind of bandwidth that make electric-only chips look downright modest -- we're talking 300Gbps per square millimeter, or 10 to 50 times what you normally see. The key was finding a way to reuse existing conventional processes to put optics in places where regular circuitry would go.