November 14, 2013
The Invisibility Cloak
“Enemy detected,” announces the officer manning the sensors.
Immediately, the captain of the interstellar spaceship turns to his engineer and calls out “Activate the stealth cloak. They will never see us coming.”
A long-standing staple of science fiction, the stealth field generator – or “cloaking system” – has long helped many spaceship captains avoid enemy detection or allowed for enemy scouts to sneak into our heroes’ base of operations. Even as recently as in Thor: The Dark World, we see the dark elves use fields of invisibility to hide their massive starships as they attack Thor’s homeworld of Asgard. While not as perfect at concealment as that alien technology, stealth cloaks are no longer a thing of science fiction. Thanks to modern innovations in the field of electrical engineering, they have become an incredible reality.
Developed by Professor George Eleftheriades and his student, Michael Selvanayagam, of The Edward S. Rogers Sr. Department of Electrical & Computer Engineering at the University of Toronto, the stealth cloak works on the same principles of how we are able to see. When light hits an object, that light bounces off and is detected by your eyes, allowing you to see the object in question. The stealth cloaks operates through the realization that radar works the same way, only using radio waves instead of light. The stealth cloak surrounds an object in small antennas that, as one, radiate an electromagnetic field. That field cancels out any radio waves directed to the object, scattering them, and forcing them to move around the cloaked object, rendering it invisible to radar detection. This method is much simplifier than previous attempts at cloaking technology, which have attempting to coat the object in question with a layer of shifting metallic plates that bounce radio waves off. Using their method, larger objects and objects of various material construction can be concealed. Currently, this technology needs to be tuned to cancel out a specific frequency, but it is believed that this drawback could easily be overcome, allowing the antenna to adapt to various frequencies as needed, much in the same way sound dampening headphones cancel out noise.
So, what possible applications could this have? Many. While there are obvious military advantages to having stealth technology, it is important to remember that this stealth cloak focuses on radio waves. This means that structures that impede cellular signal could be cloaked so that signals between your phone and a radio tower travel unimpeded. It could also be used to make objects appear either larger or smaller on radar simply by altering the signals being received rather than canceling them out altogether. Overall, there are many beneficial applications of this latest innovation.
Sure, this radar stealth cloak may not be quite as cool as a cloak that actually turns you invisible like you might find in Lord of the Rings or a myriad of fantasy role-playing games, but it is still incredible. It exists as another example of science fiction becoming science fact.
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