A photo from open sources
University of Texas researchers say they succeeded create the world’s first one-way acoustic device – giving you the ability to hear but not allowing anyone heard you. This violates the fundamental principle of physics, known as “reverse temporal symmetry”, which suggests that if waves can move in one direction, they must be able to move in the opposite direction. In other words, if you can hear someone, then they can always hear you – for the only exception to this new device.
The device is called “unidirectional acoustic circulator. “In the illustration, the colored arrows show the movement of acoustic signals. If you imagine three people sitting around the device, a person on top can hear only the person on the right, and the person on the right – only the person left, and so on.
A photo from open sources
So how do researchers at the University of Texas managed to break the reverse symmetry? In fact, it’s on surprise is simple. As you can see in the figure, inward circular cavities of the device are built in three ordinary computer fans. TO three “ports” are connected to the cavity – acoustic guides with microphones at the ends. When the fans are off, the sound Signals are symmetrically divided between ports. Turning on the fans and by adjusting their airflow, you can achieve that the sounds from Port 1 will only arrive at Port 2, and Port 3 will be fully isolated. And if you close one of the ports, then the device will turn into a sound isolator – the sounds in it will be spread in one direction only.
This simple circuit has a great many potential applications. The most obvious are, of course, isolation of noise pollution from motorways, bars and nightclubs. Perhaps submarines, stealth bombers and other similar equipment could use the device to reduce its acoustic signature. Researchers are also working on a smaller version. apparatus in which there will be no moving parts, but instead will be solid state electronics (electro-aerodynamic pumping allows you to create a fan without moving parts).
The texas team is also working on a device that will isolate or circulate light. Isolators and circulators for Today, radio waves are already familiar technology for us (they necessary for TV and radio broadcasting, radars, as well as many others things), but to do the same with light is a completely different task. If you manage to create a device that allows the light spread in only one direction – you will find yourself in step from creating an invisibility cloak.
