Arkadiusz Sitek

In the dark, a tiny spark flashes. A gamma ray born inside a patient's body strikes a crystal and knocks out a shower of light. The detector's job is to figure out exactly where that happened. The more precise the answer, the sharper the image on the tomograph screen. The new detector resembles a honeycomb, but not a flat one — the cells narrow toward the bottom.

A camera that captures not your face but your brain itself — from the inside, layer by layer. Conventional tomographs often produce blurry images: fine details merge like letters on a fogged-up window. Engineers set out to build a device that sees clearly even what is smaller than a millimeter.