Invisibility cloaks are the stuff of movies, right? Something Harry Potter uses to fight the evils of the world, and space aliens use to gain a one up on use humans. As is often the case, however, the fantasies of fiction are now becoming realities. Researchers at the Lawrence Berkeley National Laboratory have now succeeded in creating a tiny, ultra-thin invisibility cloak, and recently published their results, marking a huge breakthrough.
Invisibility cloaks are being heavily pursued by the military. Already, militaries spend huge sums of money on camouflage and stealth technologies. Real-world, working invisibility cloaks could potentially exceed these applications. Any military will full invisibility would be able to gain a huge leg up on their enemies. Recent developments suggest that such a thing might actually be possible.
Before you get too excited and start planning out new escapades with your newfound invisibility you should know that the cloak only works on extremely tiny objects. Constructed of magnesium fluoride that is topped by tiny, brick-shaped gold antennas, scientists were able to cloak an object about 36 microns in width. That’s about a thousandth of an inch. Still, the cloak itself marks a major breakthrough, and more breakthroughs in the near future could result in a lifesize invisibility cloak.
The breakthrough marks the first time that a 3-D object has been successfully cloaked from visible light. Most currently used cloaking technologies focus on sonar and radar, rather than visible light. With visible light, camouflage is the most commonly turned to solution.
The cloak was able to reflect light back almost perfectly, rendering the tiny object nearly invisible. Getting light to reflect perfectly (or in this case near perfectly back) has long proven to be all but impossible. Even with the best mirrors, some light will be erratically bounced back. This allows our eyes and other sensors to detect objects.
Which wavelengths are reflected back and which wavelengths are absorbed go a long way in determining what colors and images we see. With the invisibility cloak, light is reflected back almost perfectly, render the object, including its edges, invisible.
The tiny gold antennas of the cloak can also be adjusted to make essentially any desired pattern. The antennas allow for the minute, near perfect control of how light reflects, which means that it may be possible to control what people see.
For now, the cloak remains in the development stage, but the breakthrough could lead to important developments further on down the road. Given the actual real world applications of such devices, and their potential in military use, funding likely won’t be hard to come buy. Regardless, an actual, functioning invisibility cloak appears to be years away, if it’s possible at all.