Figure 9. The wave emitted by the light source returns to the light source. This return process is not a normal return, but a return of time reversal. The red is the electromagnetic wave, and the blue is the time reversal return wave

From

Energy Conservation Law and Energy Flow Theorem for Transformer, Antenna and Photon

Shuang-ren Zhao

International Journal of Physics. 2023, 11(2), 56-66 doi:10.12691/ijp-11-2-1