Student Develops Harry Potter Style Invisibilty Cloak: Speed of Light Again

Article taken from dailymail.co.uk

 

The ability to become invisible has long been the stuff of fantasy films such as the Harry Potter series.But the invisibility cloak could become a reality following a scientific breakthrough by a 22-year-old student.Janos Perczel, an undergraduate at St Andrews University, says that the optical sphere he has developed could make objects invisible.

He has claimed that by slowing down light by way of an optical illusion, the light can then be bent around an object to 'conceal' it.Attempts have already been made to create invisibility cloaks but research shows that efforts are limited because any cloak would only work within certain backgrounds.

But by slowing down the rays of light, Mr Perczel says the cloak wearer can move around ever-changing backgrounds.Mr Perczel, from Hungary, came up with the idea under the guidance of 'invisibility expert' Professor Ulf Leonhardt, who teaches at St Andrews' school of physics and astronomy

The student, who is at the university where Prince William met Kate Middleton, recognised the potential of the invisible sphere and spent eight months fine-tuning his project.The key development lies in the ability of the sphere, an optical device, not only to remain invisible itself but to slow light.

According to Prof Leonhardt, all optical illusions can slow down rays of light and the sphere can be used to bend this illusion around an object, reflecting off it and making it appear to be invisible.Mr Perczel added: 'When the light is bent it engulfs the object, much like water covering a rock sitting in a river bed, and carries on its path, making it seem as if nothing is there'. "Light however can only be sped up to a speed faster than it would travel in space under certain conditions, and this restricts invisibility cloaks to work in a limited part of the spectrum, essentially just one colour.This would be ideal if somebody was planning to stand still in camouflage. However, the moment they start to move, the scenery would begin to distort, revealing the person under the cloak.By slowing all of the light down with an invisible sphere, it does not need to be accelerated to such high speeds and can therefore work in all parts of the spectrum."

A spokesman for the Institute of Physics said: 'This new development opens up further possibilities for the design of a practical invisibility cloak, overcoming the problem of light speed which other advances have struggled to address and, very impressively, this significant advance was achieved by an undergraduate student.'