'Spooky' Quantum Entanglement May Capture 'Ghost' Images

Could quantum cameras capture "ghosts?" Well, maybe not in the way most of us have imagined in horror or science fiction.

Yet optic experts at the National Institute of Standards and Technology in Gaithersburg, Maryland, have found that it is quite possible to capture images of objects from photons that never actually encountered the object's picture--a process that Einstein famously coined as "spooky."

While normal cameras work by capturing light that bounces back from an object, quantum cameras capture "ghost" images by using two separate laser beams that entangle photons. Only one beam encounters the object that's pictured, but the image can still be generated when the image strikes the camera, according to National Geographic.

"What they've done is a very clever trick. In some ways it is magical," explained quantum optics expert Paul Lett of the National Institute of Standards and Technology in Gaithersburg, Maryland, via Mother Nature Network. "There is not new physics here, though, but a neat demonstration of physics."

For the study, researchers passed a beam of light through etched stencils and through tiny cat cutouts, along with a trident that was 0.12 inches tall. A second beam of light at a different wavelength from the first was entangled with the first beam of light, though it traveled on a separate line and never hit any of the involved objects. However, the second beam of light displayed the same set of objects when a camera focused on it despite the fact that the beam never encountered the objects. (Boo!)

"This is a long-standing, really neat experimental idea," said Lett.

Only time will tell whether or not this cool yet slightly mysterious experiment will lead to something more useful. However, researchers hope that it could one day lead to improved medical imaging for doctors who need better visibility in difficult technical and performance situations. 

More information regarding the findings can be seen via the journal Nature.