Time Reversed Acoustics

Abstract

The irreversibility of time is a topic generally associated with fundamental physics. Imaging techniques, on the other hand, are usually related to engineering sciences. Remarkably, however, these two domains can be fruitfully connected to yield many applications in medicine, undersea communications, hydrodynamics and material analysis, as well as elegant experiments in pure physics. Nowadays we can intercept a spreading sound wave, time‐reverse it and send it back to the source. That should greatly enhance our ability to locate gallstones and submarines.