"Spooky" Quantum Entanglement Reveals Invisible Objects (via...

"Spooky" Quantum Entanglement Reveals Invisible Objects (via National Geographics).

In the new experiment, the physicists entangled photons in two separate laser beams with different wavelengths, and hence color: one yellow and one red.[…] The team passed the red light beam through etched stencils and into cutouts of tiny cats and a trident, about 0.12 inches (3 millimeters) tall. The yellow beam traveled on a separate line, never hitting the objects. What’s more, the etched shapes were designed to be invisible to yellow light. […] After the red light passed by the objects, the physicists ran it together with the yellow laser beam at both parallel and right angles. The red light was then discarded, and the yellow light headed for a camera. There, that yellow light revealed a picture of the object. And a negative of the picture emerged from the light that had interfered at a right angle.

"The phenomena really arises from the interference of the photons together,” Lemos says. “It’s not that the red photons have changed the yellow ones, it’s that quantum mechanics says they have to share [wavelength] phases which we can detect to see a picture.”

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Nothing spooky (unless you consider nature is spooky), and nothing new because quantum entanglement is known (and accepted) from 1935 or so. But an interesting experiment anyway, of course.