Ever wondered what the beating heart of an atomic clock looks like? Here it is. The optical atomic clock built by the UK's National Physical Laboratory (NPL). It is governed by a single ion using the element strontium.

In brief it works by the ion trapping an electromagnetic field within the small cube at the center. It is then cooled with lasers to just a fraction above absolute zero and lasers are fired through three of the glass shafts from the cube.