Introduction Have you ever tried making “walkie-talkies” using a long piece of string and two tin cans? If you have, you know that they work surprisingly well—at longer distances you can hear people ...

In the ETH experiment, self-oscillations (blue-red) cause sound waves (green, orange, violet) to travel through the circulator only in one direction. Credit: Xin Zou Researchers at ETH Zurich have ...

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. What if you could listen to music or a podcast without headphones or earbuds and without ...