The standard model of particle physics is often illustrated as a simple grid showing 17 elementary particles (see above). But another way of visualizing it reveals the complex rules that govern how particles and forces interact.
This article is part of a special series on standard models and covers:
A conventional grid shows three generations of quarks (which feel strong forces) and leptons (which do not feel forces). Then there are the bosons that mediate the three fundamental forces of nature: the strong and weak nuclear forces, and the electromagnetic force. But it doesn’t give us the whole picture.
For one, there are missing pieces, such as the fact that most particles can occur in two forms of a property called handedness: right-handed and left-handed. We also know nothing about which particles feel which forces. There are also mysteries it hides, like the fact that right-handed neutrinos don’t exist, at least as far as we know. “The standard grid looks nice, but it looks finished,” he says. Chris Quigg, Theoretical Physicist at Fermi National Accelerator Laboratory, Illinois. “But the standard model is not finished yet.”

Quigg saw the need for a new way to visualize theory that reflected its confusion. In 2005, he found the answer: the double simplex (above). Joined by the Higgs boson, he consists of two pyramids, one half representing a left-handed particle and the other half a right-handed particle. The vertices of each pyramid group generations…