By Alex Farnsworth, Michael Farnsworth and Sebastian Steinigo
Dune, the epic series of science-fiction books by Frank Herbert that has now been adapted into a film of the same name, is set in the distant future on the desert planet of Arrakis. Herbert outlined a richly-detailed world that at first glance seems so real that we can imagine ourselves within it.
However, if such a world existed, what would it actually be like?
We are scientists with specific expertise in climate modeling, so we simulated the climate of Arrakis to find out. We wanted to know whether the physics and environment of such a world would stack up against real climate models.
Here’s a view of our climate model of Arrakis:
You can zoom in on special features on our website Climate Archive and highlight things like temperature or wind speed.
When we were done, we were overjoyed to learn that Herbert had envisioned an environment that met expectations for the most part. We may need to suspend disbelief at times, but many Arrakis will actually be habitable, even if they are inaccessible.
How do you build a fantasy world like Arakis?
We started with a climate model that is commonly used to predict the weather and climate on Earth. To use these types of models you have to decide on physical laws (famous in the case of planet Earth) and then input data on everything from the size of mountains to the strength of the Sun or the texture of the atmosphere. The model can then simulate the climate and give you a rough idea of what the weather might be like.
We have decided to keep the same basic physical laws that govern the weather and climate on Earth. If our model presented something completely strange and exotic, it might suggest that those laws on Arrakis were different, or that Frank Herbert’s imaginative vision of Arrakis was simply fiction.
Then we needed to tell the climate model a few things about Arrakis, based on the main novels and the detailed information that came with it. Doon Encyclopedia. These included the planet’s topography and its orbit, which was essentially as circular as Earth is today. Orbit size may actually affect climate: see long and erratic winters game of Thrones.
Finally, we told the model what the atmosphere is made of. For the most part, it is very similar to Earth today, though with less carbon dioxide (350 parts per million as opposed to our 417 ppm). The biggest difference is ozone concentration. On Earth, there is very little ozone in the lower atmosphere, only around 0.000001 percent. On Arrakis, it’s 0.5 percent. Ozone is important because it is about 65 times more effective at warming the atmosphere than CO₂ over a 20-year period.
After we fed in all the necessary data, we sat back and waited. Such complex models take time to run, in this case, more than three weeks. We needed a huge supercomputer to be able to crunch the hundreds of thousands of calculations needed to emulate Arakis. However, what we found was worth the wait.
The climate of Arrakis is basically plausible
The books and film describe a planet with an unforgiving sun and a desolate wasteland of sand and rock. However, as you move closer to the polar regions to the cities of Araken and Carthag, the climate of the book begins to change to something that could be considered more hospitable.
Yet our model tells a different story. In our model of Arrakis, the warmest months in the tropics are around 45 °C, while in the coldest months they do not drop below 15 °C. like earth. The most extreme temperatures will actually be in the mid-latitudes and polar regions. Summers here can be as hot as 70°C on the sand (also suggested in the book). Winters are as extreme as -40 °C in the low mid-latitudes and up to -75 °C in the poles.
This is the reverse because the equatorial region receives more energy from the Sun. However, in the model, the polar regions of Arrakis have significantly higher atmospheric moisture and higher cloud cover which act to warm the climate because water vapor is a greenhouse gas.
The book says that it doesn’t rain on Arrakis. However, our model seems to suggest that there will be very small amounts of precipitation, limited to high latitudes only in summer and autumn, and only over mountains and plateaus. There will be some clouds in tropical as well as polar latitudes, which will vary by season.
The book also mentions that polar ice caps exist at least in the Northern Hemisphere, and have been for a long time. But this is where the books probably differ most from our model, which suggests that summer temperatures will melt any polar ice, and winter will have no snowfall to replenish the ice cap.
warm but livable
Can humans survive on such a desert planet? First, we must make the assumption that people like the humans in the book and movie share the same thermal tolerances as humans today. If so, contrary to the book and the movie, it seems likely that the tropics would be the most habitable zone. Since there is so little humidity, the livable wet-bulb temperature – a measure of “habit” that links temperature and humidity – is never exceeded.
The mid-latitudes, where most of the Arrakis people live, are actually the most dangerous in terms of heat. In low-lying areas, monthly mean temperatures are often above 50–60 °C, with maximum daily temperatures being even higher. Such a temperature is fatal to humans.
We know that all human life of Arrakis outside habitable places must wear “stillsuits”, designed to reclaim body moisture by sweating, urinating and breathing, to keep the wearer cool and provide potable water. is designed for. It is important as stated in the book that Arrakis receives no rainfall, no standing bodies of open water and little atmospheric moisture that can be reclaimed.
The planet gets very cold even outside the tropics, with winter temperatures that would also be uninhabitable without technology. Cities such as Arraken and Carthag will suffer from the stress of both heat and cold, just like the more extreme version of parts of Siberia on Earth, which can have both uncomfortably hot summers and brutally cold.
It is important to remember that Herbert wrote the first Dune novel in 1965. Recently Nobel-winner Tsukuro Manebe published his seminal first climate model, and Herbert did not have the advantage of modern supercomputers, or indeed any computers. Given this, the world he created is remarkably consistent over six decades.
The authors modified a well-used climate model for exoplanet research and applied it to the planet in Dune. The work was done in his spare time and is intended as a fitting outreach piece to demonstrate how climate scientists use mathematical models to better understand our world and exoplanets. This will feed into future academic output on desert worlds and exoplanets.
Alex Farnsworth is Senior Research Associate in Meteorology at the University of Bristol; Michael Farnsworth is Research Lead Future Electrical Machine Manufacturing Hub at the University of Sheffield, and Sebastian Steinig is Research Associate in Paleoclimate Modeling at the University of Bristol.
This article is republished from The Conversation under a Creative Commons license. Read the original article.