The concept of invisibility seems absolutely believable when we read about a fictional world filled with witches, wizards and centuries-old magic, but in the real world it seems just impossible to turn such fantasy into reality, especially invisibility.
Now, scientists at the University of California in Berkeley claim to have turned Harry Potter’s mischief-enabling cloak into a reality. The team of scientists, lead by Xiang Zhang of the Nanoscale Science and Engineering Center at the University of California, Berkeley, says they are a step closer to developing materials that could help them develop what they call an "invisibility cloak."
The scientists have engineered material that redirect light around objects.
These laboratory-made materials, called "metamaterials", can control visible light's direction of travel, bending it around objects to make anything from people to large objects like ships and tanks disappear.
The researchers have demonstrated for the first time the ability to cloak three-dimensional (3-D) objects using artificially engineered metamaterials that redirect radar, light or other waves around an object, like water flowing around a smooth rock in a stream. Before this, they only have been able to cloak very thin two-dimensional objects.
"In the case of invisibility cloaks or shields, the material would need to curve light waves completely around the object like a river flowing around a rock," lead researcher Xiang Zhang said. "An observer looking at the cloaked object would then see light from behind it, making it seem to disappear."
Funded in part by the U.S. Army Research Office and the National Science Foundation's Nano-Scale Science and Engineering Center, the findings show that the scientists are close to creating a way which will make humans and solid objects vanish from sight.
The findings were reported simultaneously in British journal Nature and the US-based journal Science.
Human eyes can see objects because they scatter the light that strikes them, reflecting some of it back to the eye. On the other hand, "Metamaterials", meticulously patterned thin metal sheets that can bend light in precisely the right way, keep objects out of the sight by bending electromagnetic waves so that they flow around the object like water around a rock. As none of the waves are reflected back at the observer, the object appears to be out of the sight.
The recent findings followed an earlier research at Imperial College London that achieved similar results with microwaves. An invisibility cloak layout was produced in May by Professor Sir John Pendry, a physicist at Imperial College London. His associate scientists working with him in the US had put the idea into practice. In their first experiment, they had successfully cloaked a copper cylinder.
Scientists at the time said that their "invisibility cloak" is a primitive device that keeps objects out of the sight by bending electromagnetic waves so that they flow around the object like water around a rock. As none of the waves are reflected back at the observer, the object appears to be out of the sight.
The possibility of invisibility would definitely fascinate the military, which will create objects that are invisible to radar or to shield equipment from cellphone signals.The invisibility would be ideal for hiding their tanks on the battle field.