Real Invisibility Cloak Takes Advantage of Mirage Effect
Have you ever driven down a long highway on a hot day and seen something disappear in the distance only as you get closer? Well, it was likely a mirage, and those tricky instances have tempted and tortured more than one lone wanderer in the desert.
Now, a team of researchers at the University of Dallas in Texas have taken advantage of the mirage to create an “invisibility cloak.” The cloak is said to have the ability to hide objects from one’s view. It is also claimed to work best underwater and has an instant “on” and “off” function.
How did they use the mirage? Well, first you must have a basic understanding of how a mirage works. A mirage takes place when there is a big difference in temperature over a small distance which bends light rays. These rays are seen by the eye rather than bouncing off the surface. For example, if you are in a desert and you see a pool of blue water, you are only seeing the blue sky being redirected from the warm ground into your eyes.
The researchers wanted to find a material that can conduct heat and transfer it very fast to its surrounding areas to imitate the mirage effect. They discovered that carbon nanotubes were excellent materials. The nanotubes quickly heat to high temperatures through electrical stimulation and transfer heat to their surroundings, bending the light rays away from the object hidden behind the device. Thus, the object is able to “disappear.” Sounds a bit like how Polar bear fur works.