October 25, 2007

electromagnetic wormholes could allow invisibility

I always thought the things and creatures made invisible in the fictions on tv & cinema, weren't ready to be invisible in real, because invisibility involves three dimensions, a viewer can be anywhere around the object that should be hidden, & instead of this object, he should view the scenery behind it, this part of the scenery, when the object is visible, is hidden by it, & should be emulated by the layer that covers the object in order to hide it; as the scenery behind the object is different according to where the viewer is, the image reflected by that layer should be unique for each viewer & credible of course.

that's what in my eyes makes invisibility - artificial invisibility - too complicated.

never mind if you didn't get some of or all what I was trying to explain .. to enter the topic, it seems that a group of mathematicians, of the university of rochester, recently thought up a way to build a device called "electromagnetic wormhole" that could make objects traveling through it invisible.

according to the same scientists, the electromagnetic wormhole is not what's commonly known as a "wormhole" - a feature of spacetime that is essentially a 'shortcut' through space and time that could serve for traveling over vast distances - instead, the theorized wormtunel is supposed to make an object inside it electromagnetically invisible to outside observation.

one of the scientists allan greenleaf says:
It would create a complete a disconnection between the outside world and stuff inside the cloaking region, it's good for hiding things.

the stealthiness of the electromagnetic wormhole is originated from a coating of "metamaterials", artificial substances distinguished from other composite materials for having unusual properties such as the ability to bend light in novel ways ... if for instance light is bend from some surface, this one will become invisible.

previously, in october 2006, researchers from duke university led by david r. smith, had demonstrated that a shield of metamaterials about 5 inches (13 centimeters) wide could become invisible (more about that here), however, it was not a true invisibility cloak since it only worked in two dimensions and only at microwave frequencies while humans and other animals see light at much higher frequencies.

you can read more on national geographic site from which I got the information.