Learned scientific articles generally don’t make a big splash in the world beyond academe. Many of us out here can’t understand them, and we’re much too busy and distracted to bother trying. But two articles in this month’s issue of the journal Science have made headlines that are capturing even children’s attention. British and U.S. researchers, it appears, are close to perfecting new kinds of materials that could be thrown or draped over an object to render it invisible.
Allowing for time to smooth out glitches, it could be less than two years before the world — well, all right, the world’s militaries — have invisibility cloaks not essentially different from the ones used by Harry Potter and by the Romulans and Klingons of “Star Trek.” Harry’s, you may recall, was a person-size garment that he used to get about Hogwarts School after lights-out. In “Star Trek,” the cloaking device was typically used to screen larger objects, such as a spacecraft.
Presumably any size or shape is feasible. A few tweaks might even permit a version of the fabled helmet of darkness worn by Hermes, messenger of the gods in Greek myth. Once again, science catches up to fantasy.
To be fair to others toiling in this rarefied field, the two papers released this month don’t represent an entirely new breakthrough. “Invisibility recipes” already published include one that utilizes super-lenses, which cancel out the light from nearby objects, and even one based on the same “metamaterials” used in the new research.
In 2003, a team of Japanese researchers published a paper titled “The Transparent Cloak!” that described how to make something invisible by means of optical camouflage — basically projecting a moving background image onto a masked object.
Still, if media enthusiasm is any gauge, the latest research marks some big practical steps forward. As we understand it, those metamaterials — special blends of polymers and minuscule wire coils — can now be made in such a way as to bend light and other electromagnetic waves right around the object being concealed so that a viewer would simply see whatever lies behind. The object wouldn’t even cast a shadow.
In other developments, the materials could be used to divert radar or cell-phone signals as well as sight lines. “The cloak would act like you’ve opened up a hole in space,” one U.S. researcher said, in a welcome moment of lucidity.
So yes, the excitement is understandable, and we can’t wait for these spectacular applications to materialize. We particularly like the recommendation of another U.S. team member last week: “You may wish to put a cloak over the refinery that is blocking your view of the bay.” That is an excellent idea.
In fact, why stop there? Maybe it would be possible to cloak the entire Tokyo expressway system, leaving holes only for access points. It’s hard to imagine anyone missing the sight of that sprawling concrete octopus.
At the same time, isn’t the media hubbub a bit of an overreaction? After all, human beings already have ways of making things invisible — methods so well-honed and sophisticated that they make the potential new applications seem quite crude. Politicians certainly don’t need the help of any pricey polymer-and wire cloaks to avoid seeing things they don’t want to see. Pollution, crime, graft, urban blight or simply the right thing to do: Many lawmakers are already masters of the art of blocking such things out. Just can’t see them no matter how hard they look. Memo to scientists: How about a cloak that makes things visible?
Politicians aren’t the only ones practicing selective blindness. The rest of us also exist in little worlds blocked off in every direction by virtual cloaks. The darkness comes down on natural disasters after a few days. We can barely see the war in Iraq anymore, and Afghanistan has been invisible for ages. We never could see Africa. We have a hard time making out poor people.
There are even cloaks over things right under our noses. A case of cancer or AIDS in the family might as well not be there at all. There is also a special cloak in most people’s daily newspaper that covers the rectangle where the editorials go.
So, while the new developments are undoubtedly thrilling, they may not be as novel or revolutionary as they appear. Scientists should go back and re-read their volumes of Harry Potter. There are ideas in there with even greater potential. Remember the enchanted Marauders’ Map, which shows Harry where everyone in Hogwarts is at any given time? One of those could prove very handy for the people hunting a certain man in a cave on the Afghan-Pakistani border, who evidently got hold of his own invisibility cloak nearly five years ago.
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