British defense researchers have invented an invisible tank — or at least a way to make a tank invisible. London's Daily Mail, Daily Telegraph and Sun all report on tests conducted by the Ministry of Defence last week in which a tank rolled across a field, completely invisible to observers standing at a certain point.

"This technology is incredible," an unnamed soldier was quoted by the Daily Mail and Sun. "If I hadn't been present I wouldn't have believed it. I looked across the fields and just saw grass and trees — but in reality I was staring down the barrel of a tank gun."

Before bloggers start making comparisons to Harry Potter and Romulan spacecraft, it must be noted that the "technology" relies on heavy use of camera and projectors. Basically, a camera films the background, which is then projected upon a special surface applied to something in the foreground — in this case, a tank.

A Japanese guy in a translucent raincoat has become very popular on YouTube demonstrating something similar, as you can see here.

One person was willing to go on the record in all three British newspaper stories — theoretical physicist Sir John Pendry of Imperial College London, one of the world's leading experts on surface reflectivity and lead author of a widely reported paper last year that said a "cloak of invisibility" would theoretically be possible.

"The drawback at the moment is the dependence upon cameras and projectors," the Sun quoted Pendry, who did not confirm an implied connection with the defense project. "The next stage is to make the tank invisible without them — which is intricate and complicated, but possible."

My initial reaction was "Cool!" ...until I realized that traffic cops eventually will be using this technology for speed traps. :(