Invisibility Cloak a Reality

Scientists will not say when Harry Potter's invisibility cloak will move from the realm of magic to reality (AAP)

Scientists have developed what they are calling a “metamaterial,” a three-dimensional fabric that can reverse the natural direction of light. While still in its early stages of development, researchers say that the material could very well yield the world’s first actual (i.e. not in a sci-fi novel) invisibility cloak. Now would be a good time to start recording those “fly on the wall” fantasies.

Jason Valentine, a PhD student at the University of California, Berkely, is one of the co-authors of the two papers that will be published later this week.
He has helped to create a new material that makes light bend in a way that is not found in nature.
"If you were going to use this type of material for a cloak, yes it would bend around the material," he said.
It is similar to how light bends when it enters water, and so a fish seen from an angle will appear to be in a slightly different position to its actual position.
"What we've been able to do is make bulk material which bends light [the] opposite to that of how it bends with naturally occurring materials," Mr Valentine said.
"So for example in the fish in the water scenario, if the water was a medium with a negative index of a fraction, the fish would actually appear to be above the water."
Scientists have previously created two-dimensional material that could bend light, but the team of Berkley have gone one step further - they have created a three-dimensional material.
"What we've done is taken this single layer and we've been able to stack the material, making a bulk material that's relatively thick," Mr Valentine said.
"We've found that by making that material thicker, we actually can reduce the loss, so less light is absorbed in the material.
"So this can really enable the vice applications; one of those applications could potentially be creating this cloaking."
But if you were to wear this material, what affect might it have on someone who was looking at you?
Mr Valentine says you would become invisible.
"If you were able to engineer the material properties in a certain manner and you wrapped someone in this material that's been designed, the person would essentially be invisible in that the light would bend around the person, so you wouldn't see them at all," he said.
For now the work is still in its early days and Mr Valentine will not say when Harry Potter's invisibility cloak will move from the realm of science fiction or magic to reality.
"We weren't concentrating on any of the applications, we'll see where we it goes from here and what we pursue with it," he said.
"It's a very fun area to be in for a scientist to be able to create a material that has properties that don't exist in nature."