Disorder helps to 'hyperfocus' waves in time reversal acoustics

User rating: 4.8 / 5 after 60 vote(s)

Using this phononic crystal physicists found that a medium with an orderly lattice arrangement exhibits better time compression (the signal recorded at the original source) than a disordered medium in time-reversed evanescent sound waves. Better time ...
Using this phononic crystal, physicists found that a medium with an orderly lattice arrangement exhibits better time compression (the signal recorded at the original source) than a disordered medium in time-reversed evanescent sound waves. Better time compression gives a closer approximation of the initial sound. Credit: A. Tourin, et al.

For every burst of sound, there must exist a sound that bursts in reverse, according to the theory of time reversal acoustics. From their discoveries of some surprising characteristics of mediums and frequencies, scientists have gained insight into acoustic time reversal, which could impact applications such as sending confidential messages in cryptography.


Full story »
All News summaries from Physics news
All News summaries for March 24, 2006

The Lightness of Electrons in a Twisting Metal Crystal

6 hours ago | User rating: not rated yet
(PhysOrg.com) -- A team of researchers at Princeton University's Materials Research Science and Engineering Center has observed electrons moving through a crystal of bismuth metal behaving like light.

Proposed Particle Help Explains Odd Galactic Photons

11 hours ago | User rating: not rated yet
In 2002, a satellite called INTEGRAL was launched by the European Space Agency with an instrument on board to detect and measure gamma rays from space. Four years later, it yielded some intriguing data: An unusually high ...

Electron microscopy enters the picometer scale

Jul 24, 2008 | User rating: not rated yet
Jülich scientists have succeeded in precisely measuring atomic spacings down to a few picometres using new methods in ultrahigh-resolution electron microscopy. This makes it possible to find out decisive parameters ...

Revolutionary materials reflect ancient forms

Jul 24, 2008 | User rating: not rated yet
(PhysOrg.com) -- Although order is pleasing to the eye, it can quickly become boring. In Islamic architecture therefore, decoration often follows a strict yet aperiodic pattern. Similar structures also form ...

Shielding for ambitious neutron experiment

Jul 24, 2008 | User rating: not rated yet
In science fiction stories it is either the inexhaustible energy source of the future or a superweapon of galactic magnitude: antimaterial. In fact, antimaterial can neither be found on Earth nor in space, is extremely complex ...
Goto Archive PhysOrg Forum Goto Archive Video Goto Archive Editorials Goto Archive Free Magazines Goto Archive Newsletter

News Archive