A camera took this image of a toy soldier without collecting any light that had gone near it. Instead it recorded photons with a quantum link to others that did bounce off it (Image: University of Maryland.
A normal digital camera can take snaps of objects not directly visible to its lens, US researchers have shown. The "ghost imaging" technique could help satellites take snapshots through clouds or smoke.
Physicists have known for more than a decade that ghost imaging is possible. But, until now, experiments had only imaged the holes in stencil-like masks, which limited its potential applications.
Now Yanhua Shih of the University of Maryland, Baltimore, and colleagues at the US Army Research Laboratory, also in Maryland, have now taken the first ghost images of an opaque object - a toy soldier (see image, top right).
For the rest of the story: http://www.newscientist.com/article/dn13825-quantum-camera-snaps-objects-it-cannot-see.html