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A light-speed event requires an even faster camera. A new camera setup has captured the first film of a photonic Mach cone – basically, a sonic boom with light – in real time.

“Our camera is different from a common camera where you just take a snapshot and record one image: our camera works by first capturing all the images of a dynamic event into one snapshot. And then we reconstruct them, one by one,” says Jinyang Liang at Washington University in St Louis.

The technique, called “lossless-encoding compressed ultrafast photography” (LLE-CUP), captures 100 billion frames per second, allowing it to create real-time video of scattering light with a single snapshot.

Einstein’s theory of relativity forbids anything from travelling faster than the speed of light. So Liang and his colleagues used a trick to mimic a beam of light breaking its own speed limit.

They shot a laser through a tunnel filled with dry ice fog, which was flanked by two silicone rubber panels. Because light travels through silicone more slowly than through fog, the laser pulse left a shock wave trailing behind it in a cone shape.

Ultrafast imaging is already used in medicine and the study of light, but it usually requires multiple snapshots, meaning that the event being recorded needs to be precisely repeatable. That’s not always possible in the real world.

By capturing the whole thing in one go, the LLE-CUP system eliminates that problem, and also lets researchers analyse any extra scattering of light that would distort their image.

“The whole thing about biomedical imaging is that tissue scatters light – that’s why we’re not transparent – so that degrades information content,” says , a professor of surgery and biomedical engineering at the University of California, Irvine. With LLE-CUP, we can separate the scattering from irrelevant tissues and isolate the light’s interactions with specific cells.

The system could be used with standard cameras, microscopes and even telescopes, Liang says. It could help detect the very small, like neurons firing or cancer cells, and the extremely large, like changes in the light within a supernova. “It’s got a very high ‘wow, this is amazing’ factor,” Tromberg says.

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