Remember all those times you sat in class and daydreamed about all the wonderful and terrible things you could do if you had the superpower of invisibility? Those fantasies are fiction no longer: The invisibility cloak is real.
Engineers led by Professor George Eleftheriades at the University of Colorado have constructed a scalable, thin invisibility cloak that can be modified to hide objects of various shapes and sizes.
The idea behind it is simple enough: When you see an object normally, light waves hit the object, which reflects those waves back to your eyes. This cloak, however, is covered in antennae which bend the oncoming waves around the object in all directions, thus keeping any waves from bouncing off the object. If the waves that are supposed to bounce off the object never come back, to us it’s never there. It’s invisible.
It’s electrical engineering, and not much else. Past cloaks failed to prove useful because they were “passive,” meaning they relied only on the properties of the cloak’s materials to do the job. They could only hide one frequency at a time, and in the process they actually made the object stand out more in the frequencies that weren’t being used. For example, if you made something invisible to red light, it became bright blue, which probably wasn’t the effect you wanted.
This new cloak is “active” and generates an entire electrical field around the object. It can be set to conceal an item from all types of waves on the electromagnetic spectrum at once, even visible light, as the antenna technology develops.
“There are more applications for radio than for light,” says Eleftheriades.
The military could hide tanks, submarines, and airplanes from enemy radar and sonar- this would revolutionize warfare. The military has already contacted the researchers, but they cannot say anything about it.
This technology could also remove obstacles such as large buildings that interfere with phone signals and radio stations. Rather than tear them down, just make them invisible.
The cloak can do more than just make what’s under it disappear- it can make it look smaller, bigger, or even like it’s shifting in space. It forges the object’s visual signature. The new design is also smaller and lighter than the old ones, which means that we’ll be seeing them outside the laboratory.
But will we really be seeing full blown invisibility cloaks out on the streets? This is perhaps both the most awesome and potentially dangerous technology we’ve ever created. Invisibility’s rival superpower science creation of recent years, jetpacks, seems innocent and even silly when you compare it to the possibilities disappearance provides.
