Figure 1:
(Left) In the 1940s, Richard Feynman invented a graphical method for carrying out calculations in quantum electrodynamics. A typical Feynman diagram shows the electromagnetic force mediated by photons. (Center) Bern et al. [1] use different kinds diagrams in their calculations of N=8 supergravity that permit integration of a large number of subdiagrams. Image shows an example of one of many planar diagrams used in these kinds of calculations. (Adapted from Bern et al. [13].) Owing to their resemblance to the work of artist Piet Mondrian (Right), these graphical computational devices are sometimes referred to as Mondrian diagrams.