Quantum entanglement, where two objects become intertwined and remain so no matter the distance that grows between them, is a tricky phenomenon to study let alone photograph. But scientists doing the former have now managed the latter, capturing an image of this strange bond for the first time.

Once described by Albert Einstein as “spooky action at a distance,” today we understand quantum entanglement as when a pair of particles that cross paths and interact with each other can become connected and stay that way, even when spaced very far apart. Once intertwined in this way, changes to one particle can immediately shape the other, an odd scientific phenomenon that has been proven through experiments with atoms and molecules, and more recently through entangled objects of even larger scales.

In practical terms, quantum entanglement is a key part of quantum mechanics, which forms the basis for fields such as quantum computing and cryptography, so there is considerable interest in advancing our understanding of it. For scientists at the University of Glasgow, this led them to study a form of quantum entanglement known as Bell entanglement, described by late physicist John Stewart Bell in the 1960s.

The researchers set up an experiment where a stream of entangled photons, or light particles, were fired at “non-conventional objects” atop liquid-crystal materials, which changed the phase of the photons as they passed through. With a super-sensitive camera at the ready, they were able to capture the entanglement in action, the first such photographic evidence of this long-studied scientific enigma.