Milutin Milanković (sometimes anglicised as Milutin Milankovitch; , ; 28 May 1879 – 12 December 1958) was a Serbian mathematician, astronomer, climatologist, geophysicist, civil engineer, university professor, popularizer of science and academic.
Milanković made two fundamental contributions to science: he devised advanced methods to compute slow changes in Earth's orbit that gradually redistribute insolation between the seasons and low- and high-latitude regions (now known as Milankovitch cycles), and he developed a quantitative theory of climate where these insolation cycles were sufficient to cause the recurring ice ages of the Quaternary period. While the Milankovitch cycles in insolation were confirmed and extended in subsequent research, Milankovitch’s theory of climate is broadly inconsistent with modern reconstructions of global cooling during the ice ages, the dynamic behavior of the ice sheets, as well as evidence for changing ocean circulation and greenhouse gas radiative forcing. Resolving the role of Milanković insolation cycles in pacing the recorded glacial-interglacial climate cycles remains an outstanding problem in the climate sciences.
He founded planetary climatology by calculating temperatures of the upper layers of the Earth's atmosphere as well as the temperature conditions on planets of the inner Solar System, Mercury, Venus, Mars, and the Moon, as well as the depth of the atmosphere of the outer planets. He demonstrated the interrelatedness of celestial mechanics and the Earth sciences and enabled a consistent transition from celestial mechanics to the Earth sciences and transformation of descriptive sciences into exact ones.
A distinguished professor of applied mathematics and celestial mechanics at the University of Belgrade, Milanković was a director of the Belgrade Observatory, member of the Commission 7 for celestial mechanics of the International Astronomical Union and vice-president of Serbian Academy of Sciences and Arts. Beginning his career as a construction engineer, he retained an interest in construction throughout his life, and worked as a structural engineer and supervisor on a series of reinforced concrete constructions throughout Yugoslavia. He registered multiple patents related to this area.
Life Early life
Milutin Milanković was born in the village of Dalj, a settlement on the banks of the Danube in what was then part of Austro-Hungarian Empire. Milutin and his twin sister were the oldest of seven children raised in a Serb family. Their father was a merchant, landlord and a local politician who died when Milutin was seven. As a result, Milutin and his siblings were raised by his mother, grandmother, and an uncle. His three brothers died of tuberculosis at a young age. As his health was fickle, Milutin received his elementary education at home, learning from his father Milan, private teachers, and from numerous relatives and friends of the family, some of whom were renowned philosophers, inventors, and poets. He attended secondary school (realgymnasium) in nearby Osijek, completing it in 1896.
In 1896, he moved to Vienna to study Civil Engineering at the TU Wien and graduated in 1902. In his third year of studies, Milanković found more free time for wider education. He paid his full attention to the monumental buildings of Vienna, thereby gradually understanding all the beauty of architecture. He also visited Viennese museums and galleries, after which he became an admirer of Raphael's Madonna del Prato. He showed great interest in the Vienna Opera, which he visited regularly. In addition, he devoted his attention to learning the French language by taking private lessons and attending summer French language course in Geneva in 1899. During a stay in Switzerland, Milankovitch visited the Institute for the Testing Building Materials in the Polytechnic in Zurich. In the Viennese ″Café Elisabethbrücke″, which was not fashionable but served only for reading, he spent an hour or two daily reading numerous newspapers and magazines. The professor of the science of the building bridges, , the top expert of Viennese Mechanics of that time, taught the most important subject of the fifth school year. In Brikʼs teaching, young Milankovitch found strong inspiration for later scientific work, as he describe it: ″Brikʼs lectures were very interesting to me. His mastering of mathematical analysis was excellent and would constantly apply it in his lectures. To a good mathematician it gives certain independence and freedom in solving problems.″
After graduating and spending his obligatory year in military service, Milankovitch borrowed money from an uncle to pay for additional schooling at TU Wien in engineering. At age twenty-five, his PhD thesis was entitled Contribution to the Theory of Pressure Curves (Beitrag zur Theorie der Druckkurven) and its implementation allowed assessment of pressure curves' shape and properties when continuous pressure is applied, which is very useful in bridge, cupola and abutment construction. His thesis was successfully defended on 3 December 1904; examination committee members were Johann Emanuel Brik, Josef Finger, Emanuel Czuber and Ludwig von Tetmajer. He then worked for an engineering firm in Vienna, using his knowledge to design structures.
Middle years Structural engineering At the beginning of 1905, Milanković took up practical work and joined the firm of Adolf Baron Pittel Betonbau-Unternehmung in Vienna. He built dams, bridges, viaducts, aqueducts, and other structures in reinforced concrete throughout Austria-Hungary. So Milankovitch verified his theoretical knowledge and design tools on numerous reinforced concrete structures that he built during his engineering service in Vienna. Milankovitch participated with structural calculations and practical work in the construction of a total of ten hydroelectric power plants. Among them, the most notable is the one built in Sebeș (present-day Romania) in the Transylvania region. Milankovitch's specific task was to design a reinforced concrete aqueduct 1200 m long, which would bring water above the turbines of the city's hydroelectric power plant. After that, he was engaged in the construction of the viaduct in Hirschwang (Semmering) in 1906 and in Pitten near Vienna in 1907.
He also participated in the construction of bridges in Krainburg, Banhilda and Bad Ischl, then the Belgrade and Košice sewage system, and Krupp's metal factory in Berndorf. The bridge in Krainburg (130 meters long and seven meters wide) was particularly beautiful, set on three pillars with four arches each, 30 meters apart. It was built of reinforced concrete, but was later destroyed during World War II.
Milankovitch's great reputation was certainly contributed to by inventions of a new technology of building reinforced concrete ceiling, under the name "System Milankovitch - Kreutz", with which he became famous throughout the Austria-Hungary. He developed and patented the mentioned system of building ceilings with Theodor Kreutz. Compared to the existing ones, this ceiling stood out due to its simpler design, lower consumption of materials and the fact that it had integrated thermal and sound insulation, which made it more aesthetically elegant. The "Milankovitch - Kreutz" construction system was protected by four patents for three inventions.
In 1908, Milankovitch invented and patented new and useful Improvement in the Production of hollow reinforced-concrete slabs AT 42720 B. This patent is the equivalent of Milanovitch's US patent US 940041 A.
In 1905, he published the first paper on armored concrete named Contribution to the theory of reinforced armored pillars. He published the second paper on the same subject based on new results in 1906. In 1908, he published a paper titled "On membranes of same opposition" in which he proves that the ideal shape for a water reservoir of equally thick walls is that of a drop of water. His six patents were officially recognized and his reputation in the profession was enormous, bringing abundant financial wealth.
In 1908, the Austro-Hungarian Empire decided to annex Bosnia and Herzegovina after 30 years of occupation. This was the height of a crisis with the neighboring Kingdom of Serbia, which did not agree with this act. And, there was even a growing danger of war and invasion.
Milanković continued to practice civil engineering in Vienna until 1 October 1909 when he received an offer from the University of Belgrade to work as an associate professor at the Department of Applied Mathematics that comprised three basic branches: rational, celestial mechanics, and theoretical physics. Though he continued to pursue his investigations of various problems pertaining to the application of reinforced concrete, he decided to concentrate on fundamental research.
Although this was the turning point in Milankovitch's career, he still does not abandon his "passion for the entire range of construction work, from theoretical ideas to craftsmanship", and continues to engage in design and construction, in parallel with his scientific work. Thus, after arriving in the Kingdom of Serbia, Milanković accepted the design and construction of the first reinforced concrete bridges on the Niš - Knjaževac railway, in the Timok Valley through the Nisevac Gorg, at the request of his friend and collegemate from TU Wien and civil engineer Petar Putnik. This undertaking was unique in that, at the suggestion of engineer Putnik, the type construction of a reinforced concrete bridge was applied for the first time in Serbia. The project of the 30-meter-span bridge, which rests on rocky shores, was done by Milanković with the aim of easier and faster construction of the railway on the route of which the construction of 19 bridges was planned. Thanks to this simple approach, the construction of all 19 bridges is solved with one project. That is precisely why Putnik's construction company won this job at the public procurement in 1912, when construction began. Milanković participated in the construction of the first of the nineteen bridges, which was located near Svrljig, where he fully immersed himself in the work and took care of how "the concrete is mixed, distributed over the formwork and compacted". Meanwhile, Milankovitch was granted citizenship of the Kingdom of Serbia in 1910.
Planet's insolation His first papers were in the field of celestial mechanics, Properties of motion in a specialized three-body problem (1910), On general integrals of the n-body problem (1911), On kinematic symmetry and its application to qualitative solutions of dynamics problem (1912), but from 1912 Milankovitch began to be interested in cosmic climatology or solar climate. He began working on it in 1912, after he had realized that "most of meteorology is nothing but a collection of innumerable empirical findings, mainly numerical data, with traces of physics used to explain some of them... Mathematics was even less applied, nothing more than elementary calculus... Advanced mathematics had no role in that science..."