New 'Invisibility cloak' makes objects disappear by bending light
In a video of the device in action, a goldfish suddenly appears as it swims out from under the cloak submerged in its tank. Further footage shows the lower half of a cat disappear as it steps inside a cloak placed on a table. The device uses thing panels of glass to make objects invisible by bending light around them. The team of scientists led by Baile Zhang at Nanyang Technological University in Singapore have improved on earlier versions of the cloak, which worked only with polarised light or with microwaves, instead of wavelengths visible to humans. The team of researchers said the devices could have "important security, entertainment, and surveillance applications". However, the devices are still fairly basic. They are only able to make objects 'disappear' from certain angles and the cloaks are still partially visible.
A cloaking device that uses a familiar optical illusion known as the mirage effect.
Now a group of scientists at the University of Texas have taken the concept a step further by demonstrating a cloaking device that uses a familiar optical illusion known as the mirage effect. Instead of bending light around an object to make it invisible, their approach utilizes sheets of carbon nanotubes to conduct heat, which causes light rays to bend away from the hidden object. The technology is based on the same principle that produces a similar phenomenon in the desert. Normally, our eyes make out objects by the way light bounces off them. But in this circumstance, the light never bounces but bends while passing from cooler air to the cooked high-temperature air that sits right above the sand. So instead of seeing what lies ahead, what we get is a mirage of the blue sky superimposed on the ground.