At first, the inky blobs that form the digital clockface on Zelf Koelman's Ferollic display look almost like living creatures. They pulse and dart and jump, leaving little droplets in their wake before forming into lines, patterns, and finally numbers. These blobs are actually ferrofluid: a magnetized liquid that was originally developed by a NASA engineer to guide rocket fuel to engines in zero-gravity conditions, but is now most recognizable via its artistic uses — such as Koelman's experimental Ferollic display.

Koelman explains that the display is more like an aquarium than a screen, with a basin at the bottom full of ferrofluid. "Behind the scenes, powerful electromagnets enable Ferollic to influence the fluid’s shape, to pick it up and move it around," reads the description on the site. "Both modules, the basin and the electronics, sit secure in an aluminum frame." Although the example video above shows Ferollic being used as a clock, Koelman says the controlling software is flexible and can render "text, shapes, and transitions" as well as custom animations. It doesn't sound too exciting but oh my god is it satisfying to look at:

At the moment the display is just a prototype, but Koelman is selling a limited number of 24 units for €7,500 ($8,323) apiece, with customers given the option of wood, leather, or ceramic inlays. He says that the displays are absolutely silent and produce no light at all, but would-be buyers should take note: the technology has a lifetime of only a "few months" of full usage (although future versions promise to be more long lasting). Although perhaps that's just as well considering how easy it is to lose track of time watching the Ferollic at work.