ananyo (2519492) writes "Scientists at the Massachusetts Institute of Technology in Cambridge have created a camera that is able to record images of objects hidden behind walls.
They fire a pulse of laser light at a wall on the far side of the hidden scene, and record the time at which the scattered light reaches a camera. Photons bounce off the wall onto the hidden object and back to the wall, scattering each time, before a small fraction eventually reaches the camera, each at a slightly different time. The camera captures this time-of-flight information and uses it to reconstruct an image of the hidden object (abstract)."
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