Milutin Milankovitch: the resurgence of ice stations

Etxebeste Aduriz, Egoitz

Elhuyar Zientzia

milutin-milankovitch-izotz-aroen-berpiztea
Ed. Manu Ortega/CC BY-NC-ND

The heavy iron door closed behind me... I sat in bed, looking at the room, and began to see the new situation. One day I looked at the suitcase... My brain worked again. I jumped up and opened the suitcase. There I had papers on my cosmic problem. I went over the papers, took my faithful pen and started writing and calculating... After midnight I looked at the room, it cost me to know where I was. That little room seemed like a travel accommodation in my universe.

Milutin Milankovitch was not in a hotel of the universe, but in prison. During his honeymoon Dalj traveled to his hometown, Austria-Hungary, where he was trapped by the beginning of World War I. He was arrested by the Austro-Hungarian army for being Serbian. But he was not going to stop him from continuing to work. He had to solve the mystery of the ice stations.

It wasn't long before that question of ice stations came into his head. He was an expert civil engineer in reinforced concrete. He built eleven buildings, highways, bridges, reservoirs and aqueducts in central Europe. He also drew the mathematical model of the largest building that could be built on earth: a reinforced concrete building with rotational symmetry of 21,646 km in height and 112.84 km in diameter at the base.

Milankovitch demonstrated from the beginning a great ability to mathematically solve civil engineering problems. Until 1909 he worked as a civil engineer in Vienna. That year he was offered the chair of Applied Mathematics at the University of Belgrade. Since taking that post, although he did not completely leave the reinforced concrete, he was interested in other matters. Reading the work of climatologists drew attention to the mystery of the ice age. Although he was already quite marginalized, half a century earlier, he was on top when everyone was covered with ice.

It all started with rocks. In many places isolated rocks appeared that had nothing to do with the environment. Geologists were clear that they came from somewhere else, but how did they get where they were? French naturalist Jean-André de Luc, for example, proposed that compressed air in the caves could be expelled. Many believed that they came into the icebergs, when those lands were under the sea, and that they were released by the icebergs once melted. For many others, these rocks were moved by major biblical floods.

"Not all the waters of the world would float a rock," James Hutton explained in the 13th. At the end of the 20th century. He believes that only glaciers could be the only materials to move those huge rocks. Hutton was the first to speak of a general glaciation. But that idea went unnoticed.

Half a century later others began to work this way. In 1834, when naturalist Jean Charpentier walked the mountain with a Swiss basomutile, the vasomutyl told him that some of the rocks present came from a farther granite area. Charpentier asked him how they arrived there and replied that he had transported the glaciers of Grimsel and that the glacier reached Bernardo in the past.

Charpentier was fascinated and pleased because he also reached that conclusion. Few believed that at that time. In the coming years the Swiss geologist Louis Agassiz will be the biggest ambassador of this idea. He worked without cuts around the world searching for evidence and defending the idea of the ice age. Gradually the geologists were increasing supporting the theory of ice stations. Even more so when the Scottish James Croll showed that changes in the Earth's orbit could explain the existence of ice ages in the past. And not only for one, Croll argued that there were several ice ages.

A few years later, scientists discovered that something was wrong in Croll's calculations. According to Croll, the last ice age was 80,000 years before, but the evidence found by geologists pointed out that, in any case, it should be 50,000 years later.

In this way, the theory of ice stations was again ruled out. XX. At the end of the 20th century, in the chair of geology at Harvard, the following from Agasiz said: "the supposed glacial era, which was incandescent a few years ago, we can already repudiate it without any doubt."

Milankovitch would resurrect that theory. He saw clearly that Croll was not so wrong. His theory was too simple, that was the problem. Milankovitch found that three variables influenced solar radiation coming to Earth: The inclination of the Earth's axis, the eccentricity of the orbit and the precession. And that the combination of these three variables could have to do with the appearance of ice stations. The three have very different and variable cycles, and the crosses between them required very complex and almost endless calculations.

Milankovitch was very sure of his theory. The only one I needed was time. In the next few years the calculations were redone. He did them in free time and on vacation. Even when he was arrested, he did not waste time. He entered prison and began working almost from the first minute. Subsequently, through contacts, he obtained the authorization to leave prison and pass the detention in Budapest, on condition that he appear once a week before the police. The next four years would be spent in the library of the Hungarian Academy of Sciences, without any hindrance to work on his theory.

In total he spent about 30 years working on the astronomical theory of climate change. He published about 40 articles and finally collected it in the book Canon of Insolation and the Ice-Age Problem, in 1941. There were universal laws explaining cyclical climate changes. They are known as Milankovitch cycles.

 

At that time it could not be shown that Milankovitch's cycles coincided with the ice ages and few took it into account. He died in 1958 and about 15 years later geologists began to seek evidence and claim Milankovitch's work.

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