Artist Bathsheba Grossman has been 3D printing mathematical surfaces as early as 1997. In 2002 she started to use subsurface laser engraving to produce 3D physical visualizations of data from astronomy, biology, and physics. Left image: a piece of DNA molecule. Right image: a 3D map of our nearby stars. The artist explains to us: This medium excels at imaging less structural data such as disconnected volumes, non-compact point clouds, and the convoluted strands of proteins. It works by projecting intersecting Nd:YAG laser beams into clear glass, concentrating enough energy at the intersection to create a microfracture that is precisely located within the glass. The laser is then pulsed and moved; a typical image might contain from 100,000 to several million marks. The art of the medium is in regulating position and density of the marks so that bright lines and points are produced, as well as surfaces of varying translucency, without concentrating marks so closely as to over stress the glass and produce larger fractures. Sources: http://www.bathsheba.com (2002 version). http://crystalprotein.com

As part of a zoology class, evolutionary biologist Leo Smith created a phylogenetic tree of fishes where each leaf is an actual fish specimen. Also see our other entries on physical visualizations built by re-arranging physical items. Source: Leo Smith's tweet (29 April 2018).