Sound spreads both forwards and backward in a space, meaning someone standing nearby can hear you as well as you can hear ...

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 ...

In our everyday world, waves are stubbornly democratic. Whether it’s the sound of a conversation, the glow of a lightbulb, or the undulations of the ocean, waves tend to flow equally in both ...