Vie Physarale: Evaluation of Roman roads with slime mould

TL;DR

This study uses slime mould Physarum polycephalum to experimentally evaluate and reconstruct the development of Roman road networks in Iron Age Italy, revealing strong similarities in network structure.

Contribution

It introduces a novel biological laboratory technique to analyze and simulate ancient Roman road networks using slime mould behavior.

Findings

Roman roads align with proximity graphs and minimum spanning trees.

Slime mould networks closely resemble Roman road patterns.

Reconstructed sequence of road development in Iron Age Italy.

Abstract

Roman Empire is renowned for sharp logical design and outstanding building quality of its road system. Many roads built by Romans are still use in continental Europe and UK. The Roman roads were built for military transportations with efficiency in mind, as straight as possible. Thus the roads make an ideal test-bed for developing experimental laboratory techniques for evaluating man-made transport systems using living creatures. We imitate development of road networks in Iron Age Italy using slime mould Physarum polycephalum. We represent ten Roman cities with oat flakes, inoculate the slime mould in Roma, wait till slime mould spans all flakes-cities with its network of protoplasmic tubes, and analyse structures of the protoplasmic networks. We found that most Roman roads, apart of those linking Placentia to Bononia and Genua to Florenzia are represented in development of Physarum polycephalum. Transport networks developed by Romans and by slime mould show strong affinity of planar proximity graphs, and particular minimum spanning tree. Based on laboratory experiments we reconstructed a speculative sequence of road development in Iron Age Italy.