Monday, July 27, 2009

A "Cloaking Device" for Earthquakes?

This is an amazing proposal. We now have something that could potentially be "invisible" to a broadband elastic vibrations. This includes earth's vibrations such as an earthquake.

Researchers at Aix-Marseille Université in France and at the University of Liverpool in the U.K. have now developed a barrier that keeps buildings from feeling these waves. They took a cue from stealth aircraft, which employ combinations of specially shaped and fabricated materials that absorb radar signals and deflect them off course. For earthquakes, the concept is the same: Using computers, the team modeled a device composed of layered, concentric rings of plastic, copper, and four other materials of varying flexibility and stiffness--all designed to harmlessly deflect earthquake waves.

In a series of simulations, the team bombarded the rings with the equivalent of earthquake surface waves of standard frequencies ranging from 30 to 150 hertz, or vibrations per second. The rings absorbed and redirected the waves around a central protected zone essentially without disturbing it (see illustration), the researchers report this month in Physical Review Letters. A building of the future might have such an earthquake "cloaking device" incorporated into its foundation to protect it from harmful tremors rolling across the ground.

We now need to have this thing tested beyond just simulations.


No comments: