Physicists find a way to control heat in a way once thought impossible

Physicists have designed a material that can control the direction of heat radiation, breaking a 160-year-old physics rule that once made this impossible. By combining two special materials, indium arsenide and a phase-changing substance called GST, the device can direct heat differently depending on direction and hold that setting without power. Though still theoretical, experts say it could eventually improve infrared sensing and energy systems.