How a diagram changed the world

As we have said before, design is more than just making it pretty.

Visual tools can help us to better understand ideas and concepts. Indeed, sometimes they can even shape the way we think.

Nowhere is this more evident than in Feynman diagrams.

Feynman diagrams represent the interactions of elementary particles. Before Feynman first introduced his diagrams in 1948, physicists explored and developed their understanding of such interactions by calculating complex equations.

Feynman diagrams changed that.

Richard Feynman developed the stick-figure diagrams for use in his research into quantum electrodynamics. But they rapidly proved to have much wider application. Physicists in many other fields adopted the diagrams, and they are now used throughout nuclear and particle physics, from high-energy particles to condensed matter.

Many physicists and authors have commented that the Feynman diagrams did not just help researchers to more easily make calculations, they actually changed the way physicists thought.

David Kaiser wrote that:

‘With the diagrams’ aid, entire new calculational vistas opened for physicists. Theorists learned to calculate things that many had barely dreamed possible before World War II. It might be said that physics can progress no faster than physicists’ ability to calculate. Thus, in the same way that computer-enabled computation might today be said to be enabling a genomic revolution, Feynman diagrams helped to transform the way physicists saw the world, and their place in it.’

Indeed, Frank Wilczek said that ‘The calculations that eventually got me a Nobel Prize in 2004 [for the discovery of asymptotic freedom in the theory of the strong interaction] would have been literally unthinkable without Feynman diagrams’.

So the value of the right visual tool should not be underestimated. Development and use of the right diagram have expanded the study of nuclear and particle physics, and contributed to our understanding of fundamental processes.