By cooling those two tiny metal plates to around -450 degrees Fahrenheit and separating them only by a nanometer-sized gap, their setup allowed the aluminum to act much like a single atom.

They start by taking four pictures of the same patch of sky, with ten minutes between each exposure, and compare them on a computer screen.

Grunberg's team created a sandwich of two several-atom-thick layers of magnetic iron separated by a layer of nonmagnetic chromium between them.