Heat is stubborn. Unlike light or sound, it does not travel in clear beams or waves that engineers can bend, focus, or hide with compact devices. Instead, heat spreads out slowly and relentlessly by diffusion, blurring temperature patterns as it…

Heat is stubborn. Unlike light or sound, it does not travel in clear beams or waves that engineers can bend, focus, or hide with compact devices. Instead, heat spreads out slowly and relentlessly by diffusion, blurring temperature patterns as it…