Raw chicken, ingenuity make a time-reversal mirror

No matter the angle light hits, it bounces back along the same path

mirror image of the number 5

GIVE ME FIVE  Light from an image of the numeral 5 (left) was scrambled (middle) after passing through a piece of raw chicken. Physicists reproduced the “5” (right) by bouncing laser light off a special mirror and sending it back through the chicken.

K. Lee et al/arXiv.org 2015

Light that strikes a new and improved mirror is always returned to sender.