Light trick can retrieve missed messages

Even if photons pass you by, you can snatch signal from their electromagnetic wake

SAN ANTONIO — Light may travel at the speed of light, but the information it carries doesn’t have to. Three physicists have proposed a way to receive light-based messages even when the light itself has already flown by.

The communication technique, detailed March 2 at the March meeting of the American Physical Society and in a paper to be published in Physical Review Letters, relies on measuring electromagnetic echoes that arise upon the generation of light.