The Roman dodecahedron is a small hollow object made of bronze or (less commonly) stone, the geometric shape of which is made up of twelve flat faces. Each of these faces is a pentagon.
Roman dodecahedrons also have a "knob" decoration on each of the pentagon vertices, and the pentagonal faces in most cases have round holes. More than 200 years after these mysterious objects were first discovered, scientists are not one step closer to unraveling the mystery of their origin and function.
The Roman dodecahedron dates from the 2nd or 3rd century AD and has a size ranging from 4 to 11 cm. Today, more than a hundred such artifacts have been found in the UK, Belgium, Germany, France, Luxembourg, the Netherlands, Austria, Switzerland and Hungary.
A fragment of a dodecahedron cast from a copper alloy (1 - 400 AD), discovered in Yorkshire with a metal detector, England (Portable Antiquities Scheme / Creative Commons).
The big mystery is for what purpose the Roman dodecahedrons were created. Unfortunately, there are no documents in this regard since the time of their creation, so the purpose of these artifacts has not yet been established. Nevertheless, over the centuries, many theories and assumptions have been put forward in an attempt to explain their functions: candlesticks (wax was found inside one specimen), and dice, geodetic instruments, devices for determining the optimal sowing time of winter crops, calibration tools water pipes, elements of an army standard, ornaments for a wand or scepter, toys for tossing and pole-catching, or simply geometric sculptures. Among these assumptions, some are indeed noteworthy.
According to one of the most accepted theories, the Roman dodecahedron was used as a measuring device, namely as a rangefinder on the battlefield. According to this hypothesis, the dodecahedron was used to calculate the trajectories of projectiles. This could explain the presence of different hole diameters on the pentagonal faces. According to another similar theory, dodecahedrons were used as geodesic and leveling devices. However, none of these theories have been supported by any evidence, nor have they provided comprehensive explanations of how dodecahedrons could be used for these purposes.
More interesting seems to be the hypothesis that dodecahedrons served as astronomical measuring instruments, with the help of which the optimal sowing time for winter crops was determined. According to GMC Wagemans, “The dodecahedron was an astronomical measuring device that measured the angle of incidence of sunlight and thus accurately determined one particular day in the spring and one particular day in the fall. The days thus defined, apparently, were of great importance for agriculture. However, opponents of this theory note that the use of dodecahedrons as measuring instruments of any kind seems impossible due to their lack of any standardization, since the objects found had different sizes and designs.
Roman dodecahedron found in Bonn, Germany. Source: Hadley Paul Garland / Flickr.
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Another unproven theory claims that dodecahedrons are religious paraphernalia that were once used in cult rites by the druids of Britain and Caledonia. Again, there are no written sources or archaeological finds to support this theory. Or maybe this strange object was just a toy or play accessory for legionnaires during the military campaign? According to some sources, they were the main subjects of a game similar to the modern ball game, in which these artifacts were used as targets when players threw stones in an attempt to hit them into holes in dodecahedrons.
The Dodecahedron statue in Tongeren (Belgium) as a symbol of the mystery hidden in the Roman dodecahedron (Wikimedia).
Another find made only added to the mystery of the whole story about the purpose of these items. Some time ago, Benno Artmann discovered a Roman icosahedron (twenty-hedron), which was not given due attention and, misclassifying it as a dodecahedron, was thrown into storage in a museum basement. This find raises the question of how many other geometric shapes - such as icosahedrons, hexagons, octagons - are we still to find in the vastness that was once called the great Roman Empire?
Roman icosahedron found by Benno Artmann.
Despite the fact that many questions remained unanswered, one thing is clear - the Roman dodecahedrons were objects that were highly valued by their owners. This is evidenced by the fact that some of them were found among treasures, among coins and other valuable items. We may never know the true purpose of the Roman dodecahedron, but it’s better to hope that new archaeological finds will be able to open the veil of secrecy and give us a clue to solving this ancient mystery.
Author: Federico Cataldo. Translation: Sergey Firov