Seeing inside things that can't be opened

The muon

A muon is a heavier cousin of the electron. Muons are made when cosmic rays hit the upper atmosphere, and a steady stream of them reaches the ground, passing straight through solid matter as they go.

The muon was first observed in 1936 in a cloud chamber, a sealed box of vapor where particles you can't see reveal themselves by the trail of droplets they leave behind.

Muography

Because muons pass through rock, scientists use them to image the inside of things that can't be opened. The technique is called muography. In 2017 the ScanPyramids project used it to find a previously unknown void inside the Great Pyramid of Giza, without moving a single stone.

Why it fits

That's the idea behind Muon Insight. It sees inside a computer without taking it apart, and turns what it finds into a clear answer.