It is a creepy idea: Out of nowhere a voice in your ear speaks to a appear – and none of the bystanders may perceive them. Exactly that has now been achieved in a research group at the Massachusetts Institute of Technology (mit). The special feature: you shot the Audio messages by Laser radiation into the ear.
“Our System allows the beam from some distance information directly in the ear of a Person,” said Charles M. Wynn, of the team of researchers heads toward the journal “Optical Society of America”. In order to make the light a sound, the researchers had a fascinating idea: you bring the Laser tiny amounts of water in the ear to Vibrate. “This works even under relatively dry conditions, because there is always a little water in the air. Especially in the vicinity of people,” says Wynn. In the ear the sound comes with pleasant 60 decibels.
Laser-China’s giant laser to vaporize the satellites of scrap and the US are alarmed By Gernot Kramper Slow Laser as the Audio source
The Trick is, the speed of the laser to slow down so much that the beam moves at the speed of sound. In addition, the frequency of the laser needs to be adjusted, a technique referred to as “sweeping”. “We were able to show that the sweeping of the laser beams at the speed of sound to a frequency is particularly well absorbed by water very effectively create noise,” the researchers said.
The resulting beam is very accurately steerable. Because the frequency allows to make the Sent only on a certain distance from the Laser heard, could not hear others that run through the beam, the message. In the laboratory, only the distances have been up to 2.5 meters tested, the researchers are sure, however, this distance increase rapidly.
“hope We can take this as a soon to be a commercial technology,” said a researcher of the team. The possibilities are quite versatile. It’s conceivable that direct speeches in shopping malls or in very noisy environments such as concerts. Also targeted warnings to individual persons over long distances are possible. And of course the secret instructions for the Undercover investigator, the athletes on the field or Theater actor.
The voice of God
potential for Abuse. To listen out of Nothing votes, finally, is still anything but normal. In the past, it was already rumored often that the US military had a similar technique, with the help of about Islamist fighters in Iraq in the name of Allah asked had been, to lay down their arms. The therefore, as the “Voice of God” referred to Audio-gun, but was never proved in fact. The new research results could change quickly.
