A Network Analysis-based Approach to the Romano-British Transport System

The seeds of commerce: A network analysis-based approach to the Romano-British transport system

Authors:

Orengo et al

Abstract:

Communication routes are an important subject in the study of the human past. They allowed interactions between communities and the dispersal of goods and ideas. Their study, therefore, can shed light on the way in which communities inhabited the landscape, related to each other and were affected by macro-regional trends. Many methods, such as archaeomorphological analysis and Least Cost Route modelling (LCR), have been devised and are routinely employed for the reconstruction of ancient routes. Their analysis in terms of communication, trade or historical significance, however, has usually been left unexplored. This is probably due to the connected nature of routes, which form communication networks: these are shaped by interconnected nodes and extend over territories surpassing the regional scale in such a way that even a change in a single node or link can affect the whole network. Consequently, the partial reconstruction of communication networks provided by the aforementioned methods does not usually allow a holistic analysis. In this paper the relatively well understood British Roman road network is employed to explore the analytical possibilities offered by a combination of Social Network Analysis, Spatial Network Analysis and spatial interpolation-based distribution analysis. The British road network has been reconstructed using published data but also a variation of LCR in which cost surfaces are derived from cultural data obtained from large-scale cultural inventories. The distribution of introduced food plants during the Roman period serve as an excellent proxy for the study of trade along the network and its historical consequences. This multi-period archaeobotanical dataset has some evident advantages to other types of material remains: archaeobotanical remains are not reused as, for example, amphorae and, accordingly, they reflect a distribution pattern based on consumption or commerce. Some of them are imported (as they cannot be produced locally) and, consequently, their distribution would be applied through usage of the main routes.

The results suggest a continuous inflow of exotics but highlight their changing transport routes, their differential access and the particular weight of certain nodal sites in the development of this commerce with direct impact on urbanisation and the overall economy of Britannia. The Roman road network acted as a major factor in the distribution of sites, their political and economic importance and their permanence or disappearance as global economic trends changed over time.

Network Theory Predicts Wars (or Lack Thereof?)

The study of modern history is currently undergoing a revolution. That is largely because historians are beginning to apply the ideas in network theory to the complex interactions that have forged our past.

There was a time when historians focused largely on events as the be all and end all of history. But in recent years, there has been a growing understanding that a complex network of links, alliances, trade agreements and so on play a hugely important role in creating an environment in which conflict (or peace) can spread.

An interesting open question in this regard is whether certain kinds of networks exist that are stable against the outbreak of war. Today, we get an answer thanks to the work of Matthew Jackson and Stephen Nei at Stanford University in California. These guys combine network theory and game theory to study the stability of different kinds of networks based on real-world data.

In particular, Jackson and Nai study the theoretical properties of networks consisting of countries that have military links and compared them to the properties of networks in which countries have both military and trade links.

Finally, they apply real data to their model. They combine international trade data with the well-known “Correlates of War” database to see how closely their predictions match those of real networks.

Jackson and Nei begin by considering a simple network of a handful of countries that can form military coalitions of various strengths. At the same time, each alliance must serve a purpose by helping to protect the countries involved so that the deletion of any alliance would make a country vulnerable. In this network, a country is vulnerable to attack if its coalition is weaker than its opponents’ coalition and the cost of a war is less than the benefit.

An interesting question is whether such a network can ever be stable against war. In other words, can the network exist in a way that no country is vulnerable to a successful attack by others and that no country can change alliances in a way that makes such an attack viable.

link.

The time frame's damping of wars had nothing to do with the spread of nuclear weapons.  Nope.  Not at all.

The Surprising, Hidden Vulnerabilities of the Air Traffic Network

In April 2010, an Icelandic volcano called Eyjafjallajökull suddenly erupted, spewing millions of tons of dust and ash into the atmosphere above western and northern Europe. Airborne ash can clog jet engines, so some 20 countries immediately closed their air space to commercial air traffic.

The eruption lead to the cancellation of more than 60 percent of European flights over a period of five days and affected more than 100,000 travelers.

This kind of disruption is unprecedented, but it raises an important question. How vulnerable is the global airline network to disruptions of this kind? And if one part of the network is shut, how does this disruption spread?

Today we get an answer thanks to the work of Trivik Verma at ETH Zurich and a few pals. Their conclusion is unexpected.

link.