Researchers from the University of New South Wales Sydney have developed a technology that can invisibly transmit information disguised as background thermal radiation. The technique, named "negative light," transfers 100 kilobits of data per second in a way undetectable to outside observers. The researchers used devices called thermoradiative diodes to create patterns of brighter or darker-than-usual states that can be read as data by specialized receivers. The breakthrough could have major applications in industries such as health care, defense, finance, and manufacturing. While the initial transfer rate of 100 kbps is modest, higher speeds are achievable. The team also anticipates a commercial product delivering megabit-per-second data rates within a few years.