In a study published in the journal Fafnir, researchers used the same numerical models used to simulate the earth’s climate in order to test the coherence of two cult worlds: Middle Earth by John RR Tolkien and Westeros, the universe of the saga of Iron Throne created by George RR Martin. For Middle Earth Lord of the Rings, the exercise was almost simple: Tolkien had thought of it as a mythical version of our planet in the very distant past, with a sun, a size and a rotation close to those of the Earth. The scientists therefore injected the author’s detailed maps – relief, seas, mountains – into their models and let the machine run.
The results, relayed by IFL Sciences, are edifying: the simulated climate resembles that of Western Europe and North Africa, which fits perfectly with the author’s geographical inspiration. The heaviest precipitation falls on and to the west of the Misty Mountains, while a “rain shadow effect” dries out areas to the east, just as in the real case of mountain ranges hit by prevailing moisture-laden winds.
Even in Mordor, the desolate and volcanic land of Sauron’s armies, the laws of physics prevail: simulations make it a dry subtropical region, resembling a Saharan desert, bordered by scrub and icy desert areas on the surrounding peaks. There is nothing magical about this furnace: it is simply what emerges when we place a plain surrounded by mountains in an overall Mediterranean-type climate, with prevailing winds which deprive it of part of the rain. For climatologists, these results validate Tolkien’s instinct: his fantasy world is consistent with a real climate.
For Westeros, on the other hand, it is more complicated and the continent of Martin gives more difficulty to the models. The author describes summers and winters that can last for years or even decades, without a regular cycle, in an otherwise habitable and relatively temperate world. However, with a stable orbit like ours and a fixed inclination of the axis of rotation, the seasons remain relatively predictable: we do not go from a summer of twenty years to a winter of a century by a simple meteorological whim.
The Chaos of Westeros
For several years, astrophysicists and climatologists have had fun searching for a celestial mechanism capable of producing such seasons. In 2013, a team proposed a scenario of a planet orbiting a binary two-star system, where the chaotic dynamics of three bodies would make any seasonal prediction impossible. Other works have imagined Westeros as a moon orbiting a gas giant, or a planet caught in a complex four-body gravitational configuration.
The new study published in Fafnir takes a different route: a planet whose axis of rotation tilts chaotically, pitching like an unstable top over the years. On Earth, our inclination (around 23.5°) varies slowly and is mainly stabilized by the presence of the Moon, which guarantees regular seasons on a human scale. In the Westeros scenario, researchers vary this inclination very quickly: if the planet were to turn in each orbit, one hemisphere would be plunged into perpetual summer and the other into permanent winter.
The Lannisters are Northerners
To experience seasons that come and go, these shifts need to occur only every few years, which would make some periods exceptionally long and cold. Simulations show that with an average inclination reduced to around 10°, Westeros could remain generally habitable, with a permanently icy North and a temperate South, provided that the planet occupies high enough latitudes. Enough to make the inhabitants of the continent – Lannister included – quasi-Nordians by force of circumstances, if we are to believe the authors.
The question of the origin of such axial chaos remains. The researchers point out that, in our case, the disappearance of the Moon could make the seasons significantly more unpredictable. In the universe of Iron Thronelegend has it that a second satellite once existed before breaking up when it got too close to the Sun. The authors therefore have fun asking the question: could the destruction of this second moon have caused this chaotic shift of the axis, thus explaining the endless winters of the novels?
Beyond the wink to fans, the objective of this work is assumed: to use imaginary worlds to talk about climate science to the general public. By showing that the laws of physics can be applied to Middle-earth as well as to Westeros, researchers hope to make complex concepts such as atmospheric circulation, the rain shadow effect or the dynamics of the earth’s axis more accessible.
“Applying physics to fictional lands is a fun way to connect audiences to environmental science”they conclude, taking up Tolkien’s requirement: even the most fantastic worlds must maintain a minimum of realism to remain credible.
