Researchers in Palo Alto in the US state of California have developed the most powerful X-ray laser in the world.
The Linac Coherent Light Source is being used to see how atoms and molecules move in living systems.
The machine is a billion times brighter than the previous generation of lasers.
Each X-ray pulse has as much power as the national grid of a large country, and a hundred are produced every second.
Prof Mike Dunne, who runs the Palo Alto facility, showed me around. He said the LCLS fired extremely fast bursts of X-rays.
"Think about a person running the hundred metres," he told me. "The difference between first place and second place is sometimes 1/100th of a second.
“Take that 1/100th of a second and divide it a million times. Then take one of those divisions and divide it another million times. And that's how fast this burst of X-rays is."
Rendition of imaging process
The LCLS takes stop-motion pictures of atoms and molecules in motion
The laser was developed at the SLAC National Accelerator Laboratory. Its systems were adapted from a particle collider. But instead of smashing atoms, it enables researchers to see what is going on in living systems and to track chemical reactions as they happen.