Physicists from the Center for Advanced Study of the City University of New York reported
Reflection in space occurs when lightor the sound collides with a certain boundary, such as a mirror or a wall, the scientists explain. More than 60 years ago, scientists first hypothesized that there are other reflections - in time. They arise when the entire medium in which the wave moves suddenly changes its properties in space. When this happens, a part of this wave turns in time, and its frequency is converted into a new one.
This phenomenon has not yet been observed forelectromagnetic waves because the optical properties of a material cannot be easily changed at the speed and magnitude required to cause temporary reflections.
Artistic illustration of the experiment. Image: Hady Moussa et al., Nature Physics
To conduct an experiment, physicists developeda special metamaterial design that could rapidly change properties. They injected broadband signals into a winding metal strip about 6 m long printed on a board and loaded with a dense array of electronic switches connected to storage capacitors. The simultaneous operation of all switches created a timing interface, and the measured signals accurately carried a time-reversed copy of the incoming signals.
The experiment showed that it is possible to implementtime interface that performs time reversal and frequency conversion of broadband electromagnetic waves. The researchers believe this experiment will help develop small, low-power computers and exciting new applications for wireless communications.
Read more:
2,700-year-old temple found in Sudan He surprised scientists
Biochemists have identified the most likely substance that "launched" life on Earth
Named a vitamin that protects the brain from dementia