A new approach of time reversal


Can a wave be living its past life again? This issue has been widely tackled at ESPCI Paris, especially for acoustic and electromagnetic waves. The process called ‘time reversal mirror’ implies a lot of sensors and heavy electronics. Yet, teams from the Langevin Institute (ESPCI Paris/CNRS) and the PMMH Laboratory (ESPCI Paris/CNRS/UPMC/Université Paris Diderot) have just genuinely revisited this phenomenon by using space and time symmetries while avoiding any electronics.
The concept -named ‘Instantaneous time mirror’- has been tested with water waves, and the associated works have been published online in Nature Physics on 11th July 2016.


More information:
article in Physics Today


V. Bacot et al., Time reversal and holography with spacetime transformations, Nat. Phys., 2016, doi: 10.1038/nphys3810