Sight unseen: metamaterials could be used to create invisible ships
March 2, 2008 Like a lot of emerging science, the study of metamaterials is both amazingly cool and nearly impossible to understand without an advanced degree in physics or a long night on Wikipedia. It’s made Gizmag headlines before, with researchers claiming its unique structure, which has a negative refractive index, could be used to render objects invisible to the naked eye. Now scientists at Britannia Royal Navy College are working on a plan to use it to create the ultimate stealth vessel, according to a report in this month's edition of Physics World.
Unlike natural materials, which refract light to the right of the incident beam, metamaterials are “left handed”, refracting light at a negative angle, to the left of the incident beam. This allows scientists to “bend” light around the object, allowing the beams to continue as if the object were not there. Duke University succeeded in bending microwaves around metamaterials in 2006, and in the following year researchers at Ames Laboratory developed a method for bending wavelengths in the visible light spectrum. Scientists predict that invisibility will be possible for objects of any shape and size within the next decade.
Obviously the technology has definite military applications. Chris Lavers, the senior lecturer in remote sensing and sensors technology at Britannia Royal Navy College, believes the next generation of stealth ships could be virtually invisible to the human eye, roaming radars, and heat-seeking missiles, as well as disguising their sound vibrations and their impact on the Earth’s magnetic field. Lavers explains in the Physics World report: “If optical and radar metamaterials could be developed, they might provide a way to make a ship invisible to both human observers and radar systems, although the challenges of building a cloak big enough to hide an entire ship are huge.”
The current leader in Navy stealth is Sweden’s Visby Corvette. Its angular design and low-radar reflectivity material greatly reduce its radar signature. It also lacks propellers, and has the lowest “magnetic signature” of any current warship.
Via Physics World.