The vast majority of visualizations we experience in our lives come from the digital world. On rare occasion, they are printed out on a piece of paper, but even then, they are two dimensional. Even more rarely, visualizations are created in the three dimensional physical world.
Yvonne Jansen and Pierre Dragicevic have been working hard on developing and evaluating methods for visualizing data in the physical world. Their recent work on physical 3D bar charts shows that making things tangible has an advantage over digital 3D and even 2D visualizations. One part of evaluating the physical world as a place for visualizations to exist is to look at the history of tangible visualizations.
They have been compiling a list of physical objects and installations that show data in some way. This list ranges from as early as 5500 BC all the way up to present day. The list just reached 100 entries, with a wide range of sophistication in the objects, ranging from handmade clay all the way up to 3D laser etched objects and computer controlled actuated canvases.
The list is great to browse through, both as a historical reference, and as possible inspiration for visualizations both digital and physical. As 3D printing, milling, plasma cutting, laser cutting, actuated displays, and pipe bending techniques get more sophisticated, the boundary between digital data and physical visualizations will continue to get easier to cross. Lists like this help to establish what techniques already exist, and which areas have plenty of room for exploration.