Milutin Milanković (Serbian: Милутин Миланковић, pronounced [milǔtin milǎːnkɔʋitɕ]; 28 May 1879 – 12 December 1958) was a Serbian mathematician, astronomer, geophysicist, climatologist, civil engineer, doctor of technology, university professor, and writer. Milanković gave two fundamental contributions to global science. The first contribution is the "Canon of the Earth’s Insolation”, which characterizes the climates of all the planets of the Solar system. The second contribution is the explanation of Earth's long-term climate changes caused by changes in the position of the Earth in comparison to the Sun, now known as Milankovitch cycles. This explained the ice ages occurring in the geological past of the Earth, as well as the climate changes on the Earth which can be expected in the future. He founded cosmic 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 consistent transition from celestial mechanics to the Earth sciences and transformation of descriptive sciences into exact ones.
House in
Dalj where Milanković was born
Milanković as a student in Vienna.
Milutin Milanković was born in the village of Dalj, a settlement on the banks of the Danube in what was then part of Austro-Hungary (and is now part of Croatia). Milutin and his twin sister were the oldest of seven children. Their father was a merchant, landlord, and local politician who died when Milutin was eight; his mother, grandmother, and an uncle then raised the children. His three brothers died of tuberculosis as children. Being of sensitive health, he received his elementary education at home (in “the classroom without walls”), 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 in nearby Osijek, completing it in 1896.
In October 1896, at the age of seventeen, he moved to Vienna to study Civil Engineering at the Vienna University of Technology and graduated in 1902 with the best marks. In his memoirs, Milanković wrote about his lectures on engineering: "Professor Czuber was teaching us mathematics. His every sentence was the masterpiece of strict logic, without any extra word, without any error." After graduating and spending his obligatory year in military service, Milanković borrowed money from an uncle to pay for additional schooling at the Technical High School in engineering. He researched concrete and wrote a theoretical evaluation of it as a building material. At age twenty-five, his Ph.D. thesis was entitled Theory of Pressure Curves (Beitrag zur Theorie der Druck-kurven) and its implementation allowed for assessment of pressure curves' shape and properties when continuous pressure is applied, which is very useful in bridge, cupola and abutment building.[1] His thesis was successfully defended on December 12, 1904; examination committee members were Johan Brick, Josef Finger, Emanuel Czuber and L. Tetmayer. He then worked for an engineering firm in Vienna, using his knowledge to design structures.
Building of a
reinforced concrete bridge on the railway Niš-Knjazevac (Serbia) as per the project of Milanković in 1913.
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. The result was particularly evident in the extraordinary design of a reinforced-concrete aqueduct for a hydroelectric power plant in Sebeș, Transylvania, which Milanković designed at the beginning of his career.
In addition to the aqueduct in Sebeș (which resembled the ancient bridges), he designed the aqueducts in Semmering and Piten (now Austria), bridges in Kranj (Slovenia), Banhildi (Hungary), Isla (Austria), and a new Krup metal factory in Berdorf. As a representative of Krupp, he participated in the construction of a collector within the Belgrade sewage system on the banks of the Sava River.
Milanković continued to practice civil engineering in Vienna until 1 October 1909 when he was offered the chair of applied mathematics (rational, celestial mechanics, and theoretical physics) at the University of Belgrade. The year 1909 marked a turning point in his life. Though he continued to pursue his investigations of various problems pertaining to the application of reinforced concrete, he decided to concentrate on fundamental research. Whenever the circumstances permitted, he would take the opportunity to visit Vienna and other places in Austria to meet friends and collaborators, participate in the work of important scientific gatherings, or participate in major construction works as a consultant or designer.
Milanković continued to to design and construction work when he moved to Serbia. During 1912, he designed the reinforced bridges in the Timok valley on the railway line Niš-Knjazevac.
While studying the works of the contemporaneous climatologist Julius von Hann, Milanković noticed a significant issue, which became one of the major objects of his scientific research: a mystery ice age. Despite having valuable data on the distribution of ice ages, climatologists and geologists could not discover the basic causes, that is, the different insolations of the Earth during past ages remained beyond the scope of these sciences. Milanković also studied the works of Joseph Adhemar and James Croll, whose pioneering theories on the astronomical origins of ice ages were formally rejected by their contemporaries. But Milanković decided to follow their path and attempt to correctly calculate the magnitude of such influences. Milanković sought the solution of these complex problems in the field of spherical geometry, celestial mechanics, and theoretical physics.
His first work described the present climate on Earth and how the Sun’s rays determine the temperature on Earth’s surface after passing through the atmosphere. He published the first scientific paper on the subject entitled "Contribution to the mathematical theory of climate" in Belgrade on April 5, 1912.[2] His next paper was entitled "Distribution of the sun radiation on the earth's surface" and was published on June 5, 1913.[3]. He correctly calculates the strength of insolation and developed a mathematical theory describing Earth’s climate zones.[4] Then he tried to find a mathematical model of a cosmic mechanism as to describe the Earth's geological and climatic history. He published a paper on the subject entitled "About the issue of the astronomical theory of ice ages" on 1914. But the cosmic mechanism was not an easy problem, and Milanković took 2 years to develop an astronomical theory.
At the same time, the July crisis between the Austro-Hungarian empire and Serbia broke out, which led to World War I. On June 14, 1914, Milanković married Kristina Topuzovich and went on his honeymoon to his native village of Dalj in Austro-Hungary, where he heard about the beginning of the World War I. He was arrested as a citizen of Serbia and was interned by the Austro-Hungarian army in Neusiedl am See. He described his first day in prison, where he waited to be taken to the Esseg fortress as a prisoner of war, in the following words:
-
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- "The heavy iron door closed behind me....I sat on my bed, looked around the room and started to take in my new social circumstances… In my hand luggage which I brought with me were my already printed or only started works on my cosmic problem;there was even some blank paper. I looked over my works, took my faithful ink pen and started to write and calculate...When after midnight I looked around in the room, I needed some time to realize where I was. The small room seemed to me like an accommodation for one night during my voyage in the Universe.”
His wife went to Vienna to talk to Emanuel Czuber, who was his mentor and a good friend. Through his social connections, Professor Czuber arranged Milanković's release from prison and permission to spend his captivity in Budapest with the right to work.
Milankovitch tables of average temperature latitudes on Mars in 1916.
Immediately after arriving in Budapest, Milanković met the Director of the Library of the Hungarian Academy of Science, Koloman von Szilly who, asa mathematician, eagerly accepted Milanković and enabled in to work undisturbed in the Academy's library and the Central Meteorological Institute.[5] Milanković spent four years in Budapest, almost the entire war. He used mathematical methods to study the current climate of inner planets of the solar system. In 1916 he published a paper entitled "Investigation of the climate of the planet Mars".[6] Milanković calculated that the average temperature in the lower layers the atmosphere on Mars is −45 °C (−49 °F) and average surface temperature is −17 °C (1 °F). Also he concluded: "This large temperature difference between the ground and lower layers of the atmosphere is not unexpected. Great transparency for solar radiation makes that is the climate of Mars very similar to high altitudes climate of our Earth." Today it is known that the average temperature is −55 °C (−67 °F),[7] but that the ground temperatures and air temperatures generally differ.[8] In any case, Milankovitch theoretically proved that Mars has an extremely harsh climate.[9] He was also studied the climates of Venus, Mercury, and the Moon.[10]
After World War I, Milanković returned to Belgrade with his family on 19 March 1919. He continued his professorial career, becoming a full professor at the University of Belgrade. From 1912 to 1917, he wrote and published seven papers on mathematical theories of climate both on the Earth and on the other planets. He formulated a precise, numerical climatological model with the capacity for reconstruction of the past and prediction of the future, and established the astronomical theory of climate as a generalized mathematical theory of insolation. When these most important problems of the theory were solved, and a firm foundation for further work built, Milanković finished a book which was published in 1920, by the Gauthier-Villars in Paris under the title "Théorie mathématique des phénomènes thermiques produits par la radiation solaire" (Mathematical theory of thermal phenomena caused by solar radiation). Immediately after the publication of this book in 1920, meteorologists recognized it as a significant contribution to the study of contemporary climate.
The works of Vilhelm Bjerknes in 1904, Milanković in 1920, and Lewis Fry Richardson in 1922 are the foundation of modern numerical weather prediction.
Milanković put the Sun at the center of his theory, as the only source of heat and light in the Solar system. He considered three cyclical movements of the Earth: eccentricity (100,000-year cycle - Johannes Kepler, 1609), axial tilt (41,000-year cycle - from 22,1° to 24,5°; Presently, the Earth's tilt is 23.5°.), and precession (23,000-year cycle - Hipparchus, 130 BC). Each cycle works on a different time scale and each affects the amount of solar energy received by the planets. These orbital variations, which are influenced by gravity of the Moon, Sun, Jupiter, and Saturn (Perturbations), are the basis of the Milankovitch cycle.[11]
Milanković was elected a corresponding member of the Serbian Academy of Sciences and Arts in 1920 and became a full member in 1924; he was also elected to the German Academy of Naturalists "Leopoldina" in Halle, Saxony-Anhalt and the Italian Institute of Paleontology. Meteorological service of the Kingdom of Yugoslavia became a member of International Meteorological Organization - IMO (founded in Brussels in 1853 and in Wien in 1873) as a predecessor of present World Meteorological Organization, WMO. Academician Milutin Milankovic was representative Kingdom of Yugoslavia there for many years.
His works on astronomical explanations of ice ages, especially his curve of insolation for the past 130,000 years, received support from the climatologist Wladimir Köppen and geophysicist Alfred Wegener. Köppen noted that Milankovitch's theory is useful for paleoclimatological researchers. Milanković received a letter on September 22, 1922 from Wladimir Köppen, who asked him to expand his studies from 130,000 years to 600,000 years. Milankovitch spent 100 days doing the calculations and prepared a graph of solar radiation changes at geographical latitudes of 55°, 60° and 65° north for the past 600,000 years. Milanković believed that these were the altitudes on the Earth most sensitive to the change of thermal balance.
These curves showed the variations in insolation which were responsible for the series of ice ages. Köppen felt that Milanković’s theoretical approach to solar energy was a logical approach to the problem. His solar curve was introduced in a work entitled "Climates of the geological past", published by Wladimir Köppen and his son-in-law Alfred Wegener in 1924.
In the period from 1925 to 1928, Milanković wrote the popular-science book "Through Space and Centuries – Letters of an Astronomer". It was written in the form of letters to an unknown lady. In this book, readers were taken through the time of formation and cooling of the Earth, then through the ancient civilizations, where he introduces them to the famous ancient and Renaissance thinkers, as well as to his contemporaries, Köppen and Wegener, and to his mathematical climate theory and his ice age cycles. Milanković also takes his readers to the Moon, Mars, Venus, and other planets of the Solar System. Milanković further describes the complicated problems of celestial mechanics in a more simplified manner.
Then Milanković wrote the introductory portion of "Mathematical science of climate and astronomical theory of the variations of the climate" (Mathematische Klimalehre und Astronomische Theorie der Klimaschwankungen), published by Köppen (Handbook of Climatology; Handbuch der Klimalogie Band 1) in 1930 in German, which was translated into Russian in 1939.
In the period 1934 Milanković had correspondence with his countryman Nikola Tesla. Next year, Milanković was published the book "Celestial Mechanics". The main characteristic of this textbook is that in it vector calculus is introduced and used systematically in solving problems of celestial mechanics.
In the period from 1935 to 1938, Milanković calculated that ice cover depended on a change in insolation. Milanković succeeded in defining the mathematical relationship between summer insolation and altitude of the snow line. In this way he defined the increase of snow which would occur as a consequence of any given change in summer insolation. He published his results in the study “New Results of the Astronomic Theory of Climate Changes” in 1938. Geologists were given a graph for presenting bordering altitudes of ice covers any period of time during the last 650,000 years.
Wegener (
left) and his associate in Greenland on November 1930.
Milanković also had a part in developing the theory of continental drift. Conversations with Wegener, the father of this theory, got Milanković interested in the interior of the Earth and the movement of the poles, so he told his friend that he would investigate polar wandering. In November 1929, Milanković received an invitation from Professor Beno Gutenberg of Darmstadt to collaborate on a ten volume handbook on geophysics and to publish his views on the problem of the secular variations of the Earth’s rotational poles. In the meantime, Wegener died in 1930 during the fourth expedition to Greenland. Milanković became convinced that the continents ‘float’ on a somewhat fluid subsurface and that the positions of the continents with respect to the axis of rotation affect the centrifugal force of the rotation and can throw the axis off balance and force it to move. In the period from 1930 to 1933, working on the problem of numerical secular rotation pole movements, Milanković developed the geographic coordinates φ and λ (φ corresponding to geographic latitude and λ to geographic longitude). These coordinates were used for calculating Earth’s trajectory. The equations are as follows:
geographic latitude
-
-
-
-
-
- Failed to parse (Missing texvc executable; please see math/README to configure.): \sin \phi= \frac{\cos \xi \sin (\phi_1 + \gamma)}{cos \gamma}
where
- ξ = part of spherical triangle,
- φ1 is geographic co-ordinates of point 1 and
- γ = angle of spherical triangle
geographic longitude
-
-
-
-
-
- Failed to parse (Missing texvc executable; please see math/README to configure.): \sin (\psi - \psi_1)= \frac{\sin \xi (\alpha - \beta)}{cos \phi}
where
- Ψ1 is the geographic co-ordinates of point 1
- α and β are angles of spherical triangle.
The equations further led to a determination of the 25 most characteristic points with pole trajectories for both hemispheres. This mathematical calculation led Milanković to 16 important points from the past that form parts of early explorations; 8 points triggered future explorations. He drew a map of the path of the poles over the past 300 million years and stated that changes happen in the interval of 5 million years (minimum) to 30 million years (maximum). This was a linear positioning of pole rotation trajectories, and was therefore unsatisfactory to Milanković. Numerous measurements performed after the second half of the 20th century show that the abovementioned time division cannot be linear. The equations used in paleomagnetism to find pole location in the Earth’s geological past are identical to Milankovitch’s equations.[12] In any case, paleomagnetists in 1950s led the revival of the theory of continental drift and its transformation into the theory of plate tectonics.[13] Milankovitch published his scientific paper on the subject entitled "Secular shift of the Poles – in memory of Alfred Wegener" in Belgrade in 1933.
At same time, Milanković wrote four sections of Beno Gutenberg's "Handbook of Geophysics" (Handbuch der Geophysik) - "The Earth's Position and Movement in Space", "Rotational Movement of the Earth", "Secular shift of the Poles", and "Astronomic Means for Climate Study during the Earth's history" - published by Wegener's father-in-law Köppen on 1933. The lecture on the apparent shift of poles was held at a congress of Balkan mathematicians in Athens in 1934 (True polar wander).
To collect his scientific work on the theory of solar radiation that was scattered in many books and magazines, Milanković began his life's work in 1939. This tome was entitled "Canon of Insolation of the Earth and Its Application to the Problem of the Ice Ages", which covered his nearly three decades of research, including a large number of formulas, calculations and schemes, but also summarized universal laws through which it was possible to explain cyclical climate change and the attendant 11 ice ages - his namesake Milankovitch cycles.[14]
Milanković spent two years arranging and writing the "Canon". The manuscript was submitted to print on April 2, 1941 – four days before the attack of Nazi Germany and its allies on the Kingdom of Yugoslavia. In the bombing of Belgrade on April 6, 1941, the printing house where his work was being printed was destroyed; however, almost all of the printed sheet paper remained undamaged in the printing warehouse. After the successful occupation of Serbia on May 15, 1941, two German officers and geology students came to Milanković in his house and brought greetings from Professor Wolfgang Soergel of Freiburg. Milanković gave them the only complete printed copy of the "Canon" to send to Soergel, to make certain that his work would be preserved. Milanković did not take part in the work of the university during the occupation, and after the war he was reinstated as professor.
The "Canon" was issued by the Royal Serbian Academy, 626 pages in quarto, and was printed in German as "Kanon der Erdbestrahlung und seine Anwendung auf das Eiszeitenproblem". The titles of the six parts of the book are: "The planets' motion around the Sun and their mutual perturbations", "The rotation of the Earth", "Secular wanderings of the rotational poles of the Earth", "The Earth's insolation and its secular changes", "The connection between insolation and the temperature of the Earth and its atmosphere. The mathematical climate of the Earth", and "The ice age, its mechanism, structure and chronology". During the German occupation of Serbia from 1941 to 1944, Milanković withdrew from public life and decided to write a "history of his life and work" going beyond scientific matters, including his personal life and the love of his father who died in his youth. His autobiography would be published after the war, entitled "Recollection, Experiences and Vision" in Belgrade in 1952.[15]
After the war, Milanković was vice president of the Serbian Academy of Sciences (1948–1958) and became a member of the Committee 7 for celestial mechanics in the International Astronomical Union in 1948.
At the same time, Milanković began publishing numerous books on the history of science, including Isaac Newton and Newton's Principia (1946), The founders of the natural science Pythagoras – Democritus – Aristotle – Archimedes (1947), History of astronomy – from its beginnings up to 1727 (1948), Through empire of science – images from the lives of great scientists (1950), Twenty-two centuries of Chemistry (1953), and Techniques in the ancient times (1955). Milutin suffered a stroke and died in Belgrade in 1958.[16] He is buried in his family cemetery in Dalj.[citation needed]
Bust of Milutin Milanković.
After the death of Milanković, most of the scientific community came to dispute his "astronomical theory" and no longer recognized the results of his research. But ten years after his death and fifty years from the first publication, Milanković's theory was again taken under consideration. His "book" was translated into English under the title "Canon of Insolation of the Ice-Age Problem" in 1969 by the Israel Program for Scientific Translations, and was published by the U.S. Department of Commerce and the National Science Foundation in Washington, D.C..
In the beginning, recognition came slowly, but later, the theory was proven to be accurate. Project CLIMAP (Climate: Long Range Investigation, Mapping and Production) finally resolved the dispute and proved the theory of Milankovitch cycles. In 1972, scientists compiled a time scale of climatic events in the past 700,000 years from deep-sea cores. They performed the analysis of the cores and four years later, came to the conclusion that in the past 500,000 years, climate has changed depending on the inclination of the Earth's axis of rotation and its precession.[17] In 1988, a new major project COHMAP (Cooperative Holocene Mapping Project) reconstructed the patterns of global climate change over the last 18,000 years, again demonstrating the key role of astronomical factors.[18] In 1989, the project SPECMAP (Spectral Mapping Project), showed that the climate changes are responds to changes in solar radiation of each of the three astronomical cycles.[19]
In 1999, it was shown that variations in the isotopic composition of oxygen in the sediments at the bottom of the ocean follow Milankovitch theory.[20][21] There are other recent studies that indicate the validity of the original Milankovitch theory.[22] Although orbital forcing of Earth’s climate is well accepted, the details of how orbitally-induced changes in insolation affect climate are debated.[citation needed]
Milanković proposed a revised Julian calendar in 1923. It made centennial years leap years if division by 900 left a remainder of 200 or 600, unlike the Gregorian rule which required that division by 400 left no remainder. In May 1923 a congress of some Eastern Orthodox churches adopted the calendar;[23][24] however, only the removal of 1–13 October 1923 and the revised leap year algorithm were adopted by a number of Eastern Orthodox churches. The dates of Easter and related holy days are still computed using the Julian calendar. At the time of Milanković's proposal, it was suspected the period of rotation of Earth might not be constant, but it was not until the development of quartz and atomic clocks beginning in the 1930s that this could be proven and quantified.[25] The variation in the period of rotation of Earth is the chief cause of long-term inaccuracy in both the Gregorian and Revised Julian calendars.[26]
In honour of his achievements in astronomy, an impact crater on the far side of the Moon was given the name Milankovic at the 14th IAU General Assembly in 1970. His name is also given to a crater on Mars at the 15th IAU General Assembly in 1973. Since 1993 the Milutin Milankovitch Medal has been awarded by the European Geophysical Society (called the EGU since 2003) for contributions in the area of climate.[27] [28] A main belt asteroid discovered in 1936 has also been dubbed 1605 Milankovitch. At NASA, in their edition of "On the Shoulders of Giants", Milanković has been ranked among the top fifteen minds of all time in the field of earth sciences.[29]
- "In my scientific vocation I have found a pleasent shalter, for I was protected by it from many turbulences that shook the world. Under that roof I have prepared and equiped my scientific workshop, segregated from the wider world but in constant spiritual connection with famous scientists, I have created my scientific area, my indisputable spiritual property. In this workshop I have spent forty years including short breaks writting and publishing my papers."
- "Once you have caught a big fish, the small fry becomes uninteresting. I worked for 25 years on my theory of insolation and when it was completed, I was left with nothing to do. I am too old to start working on a new theory, and theories of this magnitude don’t just grow on trees."
- "Our atmosphere is women's nature, no doubt about it, she flashes of the ardent kisses of the sun, often gloomy and frowned, whenever the roaring and raging."
- "In this work, I above all want to repay my debts. In my life come across some exceptionally noble and generous people, to whom I am indebted by their kindness, and I have either failed or not been able to repay them in equal measure."
- ^ http://www.springerlink.com/content/f0552132345h5468/fulltext.pdf
- ^ http://scc.digital.nb.rs/document/II-184957
- ^ http://scc.digital.nb.rs/document/II-058359
- ^ Walther Schwarzacher p. 43
- ^ http://williamcalvin.com/bk5/bk5ch4.htm
- ^ http://www.ifa.hawaii.edu/UHNAI/NAIweb/presentations/37-Head-FollowWater.pdf
- ^ "Focus Sections :: The Planet Mars". MarsNews.com. http://www.marsnews.com/focus/mars/. Retrieved 2007-09-08.
- ^ http://passporttoknowledge.com/lfm/ask/atmosphere/Air_and_ground_temperature_in_Mars_seasons.txt
- ^ Frozen Earth: The Once And Future Story of Ice Ages by Douglas Macdougall p.123
- ^ http://resources.metapress.com/pdf-preview.axd?code=w15m82t77q3j7374&size=largest
- ^ Cyclostratigraphy and the Milankovitch Theory by Walther Schwarzache
- ^ Deutsch, E. R.. "Polar wandering and continental drift: an evaluation of recent evidence". In Munyan, A. C.. Polar wandering and continental drift. Society of Economic Paleontologists and Mineralogists, Special publication. 10. pp. 4–46. http://sp.sepmonline.org/content/sepspecpub/sepsppol/1/SEC2.body.pdf.
- ^ Glen 1982
- ^ http://video.nationalgeographic.com/video/player/national-geographic-channel/all-videos/av-6256-6460/ngc-ice-age-cycles.html
- ^ http://scc.digital.nb.rs/document/II-016015-195
- ^ Frozen Earth: The Once And Future Story of Ice Ages by Douglas Macdougall p.132
- ^ J.D Hays, John Imbrie, and N.J. Shackleton, „Variations in the Earth's Orbit: Pacemaker of the Ice Ages“, Science, 194, no. 4270 (1976), 1121–1132.
- ^ COHMAP Project
- ^ Encyclopedia of Paleoclimatology and Ancient Environments by Vivien Gornitz
- ^ Rial JA., Pacemaking the ice ages by frequency modulation of Earth's orbital eccentricity, Science, vol. 285, p. 564, 23 July 1999
- ^ Why the Ice Ages Don't Keep Time, Richard A. Kerr
- ^ Science, 11 June 2004, p. 1609
- ^ M. Milankovitch, "Das Ende des julianischen Kalenders und der neue Kalender der orientalischen Kirchen", Astronomische Nachrichten 220/5279 (1924) 379–384.
- ^ Miriam Nancy Shields, "The new calendar of the Eastern churches", Popular Astronomy 32 (1924) 407–411 (page 411). This is a translation of the paper by Milankovitch in Astronomische Nachrichten.
- ^ McCarthy, D. D. & Seidelmann, P. K., TIME From Earth Rotation to Atomic Physics (Weinheim: Wiley-VCH, 2009), Ch. 4, 5, 6, 8, 9, 12.
- ^ Blackburn, B & Holford-Strevens, L, The Oxford Companion to the Year: An exploration of calendar customs and time-reckoning (Oxford University Press, 1999, reprinted with corrections 2003), 688, 692.
- ^ http://www.egu.eu/egs/award6l.htm
- ^ http://www.egu.eu/awards-medals/award/milutin-milankovic.html
- ^ http://earthobservatory.nasa.gov/Features/Milankovitch/
Coordinates: 45°29′8.37″N 18°59′21.00″E / 45.4856583°N 18.98917°E / 45.4856583; 18.98917
