Coming Soon – The Invisible Man
It’s not as if making a cloak of invisibility to rival those in sci-fi and fantasy stories hasn’t been on the to-do list for scientists – it’s just a lot easier to come up with the idea than to make it work! The materials used to make such a device would need to have what is called a negative refractive index. The problem is that most materials with this type of index only cover certain wavelengths. That means you’d have to use only certain colors that fall within those specific wavelengths in order to actually appear invisible.
But the hunt may now be over for a material that can cover all of the wavelengths visible to the human eye. The first idea that was used in making a cloak of invisibility was to bend light around the item being cloaked. The problem was that while you couldn’t see what was being obstructed from view, it was still clear that something was there – despite matching things like polarization and phase.
Thus it was realized that something more was necessary – this means using a material that interacts with light on an electromagnetic level. One idea to solve the electric and magnetic issues was to create a new material that had all the necessary properties. Initial attempts however presented with problems in the wavelength respect, with most materials therefore only able to bend light in one specific color range. Red is a great color for camouflage if you are looking to hide some tomatoes, but isn’t so spectacular for practical purposes.
That’s why recent research is so exciting. A new material has been developed which can not only interact with magnetic and electric fields, but can do so across a wide range of the color spectrum. The current range goes from red to blue, and only leaves out the very ends of the spectrum of colors that humans can perceive. Researchers claim that with a few tweaks these crescent shaped atoms will be able to reach the rest of the spectrum. It is hoped that these atoms will lead to a real-life invisibility cloak along with many other practical inventions.