Five Ways Science Can Make Something Invisible
In our latest issue, we considered the concept of invisibility in all types of forms—an artist who camouflages himself as a political statement, the invisible malaria parasite, and people who see encrypted codes hiding vital information everywhere they look. Now we turn to the many ways in which scientists and engineers are literally cloaking objects, sounds and even moments using cutting-edge technology. These cloaking devices don’t just trick our eyes; they deceive mechanical sensors that detect different forms of energy, from light waves to magnetic radiation.
1. Some Like it Cool
It’s not easy to hide a tank, even at night. An infrared camera readily detects heat from the engine exhaust or rising off the armor after being in the sun all day. But British defense company BAE has developed a system that uses thousands of hexagonal metal panels, each a few inches in diameter, to cover a vehicle and render it invisible to infrared sensors (see above). On-board thermal cameras detect the background temperature, and the panels—which can be rapidly heated or cooled—are programmed to continually mimic it. The panels can even be set to resemble a more innocuous vehicle, like a car. They may be ready for commercial production as early as 2013.
2. Personal Magnetism
This past March, engineers in Spain and Slovakia took commercially available materials and made something rather extraordinary. Put a metal object in their small cylindrical container and it won’t be detected by airport security systems or MRI machines. The canister is made up of two concentric layers—an inner superconducting material that repels magnetic fields, and an outer material that attracts them. When combined, they make the invention (and its contents) invisible to metal detectors and other machines that rely on magnetism. The device may someday be useful to medical patients with pacemakers, allowing them to undergo exams by MRI machines without distorting the image.