Scientists funded by the Air Force have used quantum entanglement — in which pairs of particles continue to interact even after they are spatially separated — to snap this picture of a tin solider without aiming a camera directly at the object. The technique, called “ghost imaging,” has potential military or space applications, such as using aerial drones to survey of battlefields obscured by clouds, or the smoke that follows airstrikes. Yanhua Shih, who has been experimenting with entangled photons since 1995, says: “…[T]he image is not formed from light that hits the object and bounces back. The camera collects photons from the light sources that did not hit the object, but are paired through a quantum effect with others that did. An image of the toy begins to appear after approximately a thousand pairs of photons are recorded.” These are exciting times on the frontiers of physics. Researchers in Copenhagen took a step towards producing a quantum bit. And scientists at Arizona State are trying to figure out how electrons interact. Both are necessary steps towards building superfast quantum computers.
