A real photograph of a single strontium atom suspended in an electric field.

This image was taken by David Nadlinger, a physicist at the University of Oxford, and it won the 2018 Engineering and Physical Sciences Research Council (EPSRC) science photo competition.

In the photograph, the atom is held almost motionless in place by a pair of metal electrodes.

The purple glow is the result of a laser causing the atom to emit visible light, which is then captured using a standard camera with a long exposure.

Atoms are typically millions of times smaller than anything a regular camera can capture.

However, when they are excited by lasers, certain atoms emit enough light to be photographed individually — as is the case here.

The atom appears as a tiny dot in the middle of the apparatus, made visible through a phenomenon called laser cooling and trapping, which slows down its motion to keep it still long enough for imaging.

This photo is considered historic because it’s one of the few times humanity has visually captured a single atom with the naked eye (through the camera lens), instead of via electron microscopy or indirect imaging methods.