Green Comet

Milutin Milankovitch (Milankovic) was a Serbian scientist, born in 1879 in the village of Dalj, in present-day Croatia. It was then part of the Austro-Hungarian Empire. At 17 he took up Civil Engineering at the Vienna University of Technology, going on to earn a Ph.D in engineering eight years later. His thesis was on pressure curves, useful in the planning and construction of load-bearing structures like bridges. He got work with an engineering firm, concentrating on reinforced and armored concrete, until he was offered the chair of applied mathematics at the University of Belgrade in 1909. He began to concentrate on fundamental research, though he kept his hand in concrete as well.

In his research he became interested in celestial mechanics and astronomical effects on planetary climate. He found that, although scientists were finding convincing evidence of ice ages in Earth’s past, including some indications that they might be cyclical, they were unable to come up with a plausible theory to explain it. He decided to use his interest in astronomy, and his facility with mathematics, to see if he could find any patterns that might explain the cycles in Earth’s climate. He began in 1912, following up on the work of his predecessors in the field, including James Croll, whose pioneering work on astronomical influences on ice ages was rejected by geologists and climatologists of the day. Milankovitch would face the same scepticism.

He began by publishing some papers on the effects of solar radiation, and its distribution on the planet’s surface, bringing some mathematical rigor to the science of meteorology. Then he began the more onerous task of calculating the cyclical variability of the Earth’s rotation on its axis as well as its orbit around the Sun. These eventually came to be called Milankovitch cycles, when everyone finally caught up and realized he was right. I’ll discuss those cycles independently in future posts.

His work was interrupted, though only briefly, by the beginning of World War One. He was imprisoned as a Serbian enemy of the Austro-Hungarian Empire, but was soon released upon the intervention of his friend and mentor, Emanual Czuber. He subsequently was allowed to work at the Hungarian Academy of Science for the duration of the war. After the war he returned to Belgrade where he continued to create the foundation for the mathematical treatment of climate science. He calculated the curve for variations in solar radiation impinging on the Earth going back 130,000 years, extending it to 650,000 years at the urging of climatologist Wladimir Koppen. He also impressed Alfred Wegener, of continental drift fame.

Milankovitch published many more papers, as well as popular science books, including a series on the history of science. The publication of his collected works on the problem of the Ice Ages was interrupted by the Second World War, and it ended up being published in German. It was almost lost in the bombing of Belgrade when the printing house entrusted with it was destroyed. Fortunately the warehouse where the printed sheets were stored was spared.

Milutin Milankovitch died in Belgrade in 1958. After his death his work was disputed and it languished for ten years. But it slowly gained support and is now accepted by most climatologists and geologists as an accurate theory. The Milankovitch cycles have been shown to bear a close relationship with the cycles of the Ice Ages. He shares the honor of being one of Serbia’s great scientists with the legendary Nikola Tesla.

Read the series on Milankovitch cycles, beginning with orbital eccentricity.

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