Quantum Ghost Imaging
This is cool:
Ghost imaging is a technique that allows a high-resolution camera to produce an image of an object that the camera itself cannot see. It uses two sensors: one that looks at a light source and another that looks at the object. These sensors point in different directions. For example, the camera can face the sun and the light meter can face an object.
That object might be a soldier, a tank or an airplane, Ron Meyers, a laboratory quantum physicist explained during an Oct. 28 interview on the Pentagon Channel podcast “Armed with Science: Research and Applications for the Modern Military.”
Once this is done, a computer program compares and combines the patterns received from the object and the light. This creates a “ghost image,” a black-and-white or color picture of the object being photographed. The earliest ghost images were silhouettes, but current ones depict the objects more realistically.
Using virtually any light source—from a fluorescent bulb, lasers, or even the sun—quantum ghost imaging gives a clearer picture of objects by eliminating conditions such as clouds, fog and smoke beyond the ability of conventional imaging.