Invisibility box slows, bends and speeds light up to make your phone and keys disappear

Scientists have created a small box which can be used as an invisibility cloak by bending light around valuable objects like wallets, phones and keys.

Where previous efforts to make objects disappear were thwarted by the impossibility of speeding up the light which is slowed as it is bent around them, the new invention uses a light-scattering material which slows down all light around the box, meaning it can be sped up again as it goes through the cloak.

"As we seemingly slow down the light everywhere, speeding it up again in the cloak to make up for the longer path around the core is not a problem," said Robert Schittny, leader of the research project, the Independent reported.

Because of the box's small size and ease of use, it can be taken to schools and universities to demonstrate to students and inspire them into taking up a career in physics. "It is a macroscopic cloak that you can look at with your bare eyes and hold in your hands," Schittny continued. "With a reasonably strong flashlight in a not too bright room, it is very easy to demonstrate the cloaking.

"This means no fancy lab equipment, no microscopes, no post-processing of measurement data. The effect is just there for everyone to see."

The transparent box bends light around itself, causing objects inside it to disappear from view, and where forcing light to take a longer route and slowing it down was a problem for previous invisibility cloaks, scientists at the German Karlsruhe Institute of Technology (KIT) solved this by covering the box in a light-scattering material, which means the re-routed light can be sped back up again.

Researchers from KIT are to demonstrate the invisibility cloak at a conference in California in mid-May.