NationScience & Technology

“Mirage Effect” Creates First Underwater Invisibility Cloak

By Camilo Pardo • October 28, 2011 at 1:00 pm


Scientists at the University of Texas at Dallas have successfully manipulated the “mirage effect” to engineer an underwater invisibility cloak reminiscent of the cloak in the beloved Harry Potter series.

Earlier this month Dr. Ray Baughman and other researchers devised an experiment to hide objects from view using nanotechnology and photo-thermal deflection. More commonly termed the “mirage effect”, the idea behind this phenomenon is simple. A drastic change in temperature over a small distance bends light rays towards your eye as opposed to bouncing off the surface.

An example of this effect: when looking down a road on a hot summer day, a puddle of water can be seen in the distance. That puddle doesn’t actually exist; it is merely an illusion created by the deflected light photons, and you are actually seeing an image of the blue sky being redirected from the ground.

Researchers’ first step involved finding a material that would be able to facilitate the “mirage effect”, which they discovered with carbon nanotubes. These are microscopic cylindrical molecules that are 1/10,000 the thickness of a strand of hair, light as air, stronger than steel, and most importantly, they transmit heat quickly.

Dr. Baughman presented the irony of these carbon nanotubes when he stated that their original purpose was to see how they would work as speakers. Sheets of these nanotubes were aligned in an underwater container and heated to elevated temperatures through electrical stimulation. The heat that’s transferred to the surrounding areas generates a temperature gradient, which then causes light rays to bend away from the concealed object. Ta-da! The object has now disappeared to the naked eye.

Soon, we could all be as cool as Harry Potter! (Disclaimer: Invisibility cloak does not include wand. Or magic.) | Photo courtesy of Wikimedia Commons.

As of now, scientists have only managed to create this “invisibility cloak” in an underwater setting. Yet this success has prompted an array of possibilities that include military use. The cloaking device could be used to disguise military submarines, assuming that enemy subs don’t have heat-seeking torpedoes…

Although no practical use for humans has yet been found for this cloaking device (because of the whole constantly-applied-heat thing), this experiment may lead to future technological innovations in the field of nanotechnology. The mysticism surrounding invisibility will no longer be only a part of science fiction novels, but reality. Take that, Harry Potter.


Camilo Pardo (CAS ’13) hails from the land of crabcakes and Old Bay (Baltimore). Here at BU, he studies Environmental Policy and Public Health. When he is not in class, he’s playing his guitar, Paloma. If you want to discuss anything music or science, he is your go-to guy.



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