The greatest hypothetical question of all time may be one step closer to being answerable. No, no one has yet invented a horse-sized duck or a thousand duck-sized horses. I'm talking about the greatest hypothetical question: flight or invisibility?
Experiencing something approaching human flight has long been possible. For a price, anyone can leap out of a plane with a parachute, and jetpacks can make up the difference. As for the second, more elusive part of the equation? Researchers from Texas and Toronto say they have invented two different types of invisibility cloaks. For now, these devices only make things seem to disappear on wavelengths undetectable to the human eye, but researchers on both products say a full-scale invisibility cloak is no longer just an impossible dream.
While the allure of the power of invisibility goes back at least as far as H.G. Wells' The Invisible Man—if not Greek mythology— it first became a scientific reality in 2006. That year, researchers at Duke University had created a cloaking device that could make tiny, two-dimensional objects appear invisible to microwaves.
But this cloak, and others like it, were a far cry from anything you'd read about in a Harry Potter book or see in a Star Trek episode (*required references in any article about invisibility cloaks*). One of the major problems, according to a new paper from Dr. Andrea Alú from the University of Texas (Austin), is that while it makes objects invisible in one frequency, it actually makes them more visible under another frequency. An object made invisible in red light, for example, would be even more visible in blue light.
But Alú says he has invented a new type of device that fixes that problem. Like the cloaks of yore, Alú's new design uses meta-materials (synthetic textiles with properties not found in nature) that can bend light around an object and make it look like it's not there. But, by adding an electronic source like a batter to the cloak (making the cloak "active" as opposed to "passive"), Alú says he can make objects transparent at "all angles and over all broad bandwidths."