Milutin Milankovich Biography

Milutin Milankovich is best remembered for formulating the orbital or astronomical variation theory of climatic change in the 1930s. The Milankovich theory, as it is known, proposes that as the Earth travels through space, three distinct cyclic movements combine to cause variations in the amount of sunlight that falls on the planet. These variations, according to the theory, are what produce changes in the ebb and flow of ice fields. Most of the scientist's best efforts were aimed at reconstructing Earth's and the other planets' past climates.

Milankovich was born on May 28, 1879 in the town of Dalj, near Osijek, Croatia (then Austria-Hungary). After receiving a degree in 1902 from the School of Civil Engineering for a thesis on building a bridge using reinforced concrete, Milankovich finished his doctorate in 1904 at the Institute of Technology. The following year, he joined a prestigious civil engineering firm in Vienna and began working on projects to build bridges, viaducts, dams, and aqueducts using reinforced concrete.

In 1909, Milankovich left the professional world for good when he accepted a position as chair of the Applied Mathematics Department at the University of Belgrade. He continued to investigate applications for reinforced concrete, but from that time, Milankovich dedicated most of his energy to fundamental research. Beginning in about 1912, he turned his attention to solar climates and how temperatures affect the planets.

World War I began in 1914. Milankovich, who had just married at the time, became a prisoner of war soon afterward. He was interned at Nezsider and then Budapest. In Budapest, however, his captors allowed him to continue his climatic research at the Hungarian Academy of Sciences Library. The war ended in 1918, and by 1920 Milankovich had published his first monograph on climatology, which he called "A Mathematical Theory of Thermic Phenomena Caused by Solar Radiation."

The paper brought Milankovich a significant amount of attention from the academic world, especially for his description of a "curve of isolation" at the Earth's surface. Although admired, this theory was not widely accepted until 1924, when other meteorologists discussed the curve more extensively in a textbook on geological climates. His fame renewed, in 1927 Milankovich was invited to contribute to two handbooks on climatology and geophysics.

Continuing his research into the 1930s, Milankovich developed the theory that the key to decoding the characteristics of past climates was the amount of solar radiation that the Earth received ("insolation"). This always varies by latitude, but according to Milankovich it also depends on three factors: the ellipticity of the Earth's orbit, which changes over time from virtually circular to more elliptical; precessional changes over about 21,000 years that determine which hemisphere receives more sunlight; and the subtly changing tilt of the planet's axis over thousands of years. He used this theory to explain the advance and retreat of ice over periods of 10,000-100,000 years, although he could not explain what caused the ice ages to happen in the first place.

In 1941, on the eve of World War II, Milankovich published his Canon of Insolation of the Earth and Its Application to the Problem of the Ice Ages. However, it would not be until the late 1960s and early 1970s, after sampling of deep-sea sediments and advanced climate modeling, that scientists would accept Milankovich's views as correct. His Northern Hemisphere summer radiation curves for the last 650,000 years, on the other hand, are not considered valid today.

Milankovich was also interested in the history of scientific development and wrote two books on the topic: Through the Realm of Science and Through Space and Centuries. He wrote an autobiography, Recollection, Experiences, and Vision, although this has not been translated into English. Milankovich died in Belgrade on December 12, 1958.