Milutin Milanković (sometimes
anglicised
Anglicisation is the process by which a place or person becomes influenced by English culture or British culture, or a process of cultural and/or linguistic change in which something non-English becomes English. It can also refer to the influen ...
as Milankovitch; sr-Cyrl, Милутин Миланковић ; 28 May 1879 – 12 December 1958) was a Serbian
mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems.
Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change.
History
On ...
,
astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...
,
climatologist
Climatology (from Greek , ''klima'', "place, zone"; and , ''-logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. This modern field of study ...
,
geophysicist
Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' som ...
,
civil engineer
A civil engineer is a person who practices civil engineering – the application of planning, designing, constructing, maintaining, and operating infrastructure while protecting the public and environmental health, as well as improving existing ...
and
popularizer of science
''Popular Science'' (also known as ''PopSci'') is an American digital magazine carrying popular science content, which refers to articles for the general reader on science and technology subjects. ''Popular Science'' has won over 58 awards, inclu ...
.
Milanković gave two fundamental contributions to global science. The first contribution is the "Canon of the Earth's
Insolation
Solar irradiance is the power per unit area ( surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument.
Solar irradiance is measured in watts per square metre ...
", which characterizes the climates of all the planets of the
Solar System
The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...
. The second contribution is the explanation of
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...
's long-term
climate changes caused by changes in the position of the Earth in comparison to the
Sun
The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
, now known as
Milankovitch cycles
Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term was coined and named after Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he hypot ...
. This partly explained the
ice age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...
s 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 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
Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...
,
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...
, and the
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
, as well as the depth of the atmosphere of the outer planets. He demonstrated the interrelatedness of
celestial mechanics
Celestial mechanics is the branch of astronomy that deals with the motions of objects in outer space. Historically, celestial mechanics applies principles of physics (classical mechanics) to astronomical objects, such as stars and planets, ...
and the Earth sciences and enabled a consistent transition from celestial mechanics to the Earth sciences and transformation of
descriptive science
Descriptive research is used to describe characteristics of a population or phenomenon being studied. It does not answer questions about how/when/why the characteristics occurred. Rather it addresses the "what" question (what are the characteris ...
s into
exact ones.
Life
Early life
Milutin Milanković was born in the village of
Dalj
Dalj ( sr-Cyrl, Даљ, hu, Dálya, german: Dallia, la, Teutoburgium) is a village on the Danube in eastern Croatia, near the confluence of the Drava and Danube, on the border with Serbia. It is located on the D519 road, south of its intersec ...
, a settlement on the banks of the
Danube
The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , pa ...
in what was then part of
Austro-Hungarian Empire
Austria-Hungary, often referred to as the Austro-Hungarian Empire,, the Dual Monarchy, or Austria, was a constitutional monarchy and great power in Central Europe between 1867 and 1918. It was formed with the Austro-Hungarian Compromise of ...
. 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 eight. As a result, Milutin and his siblings were raised by his mother, grandmother, and an uncle. His three brothers died of
tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, ...
as children. As his health was fickle, Milutin 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
Osijek () is the fourth-largest city in Croatia, with a population of 96,848 in 2021. It is the largest city and the economic and cultural centre of the eastern Croatian region of Slavonia, as well as the administrative centre of Osijek-Baranja ...
, completing it in 1896.
In October 1896, at the age of seventeen, he moved to
Vienna
en, Viennese
, iso_code = AT-9
, registration_plate = W
, postal_code_type = Postal code
, postal_code =
, timezone = CET
, utc_offset = +1
, timezone_DST ...
to study Civil Engineering at the
TU Wien
TU Wien (TUW; german: Technische Universität Wien; still known in English as the Vienna University of Technology from 1975–2014) is one of the major universities in Vienna, Austria. The university finds high international and domestic recogn ...
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 TU Wien in engineering. He researched concrete and wrote a theoretical evaluation of it as a building material. At age twenty-five, his
PhD PHD or PhD may refer to:
* Doctor of Philosophy (PhD), an academic qualification
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** Ph.D. (Ph.D. al ...
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 12 December 1904; examination committee members were Johan Brick,
Josef Finger,
Emanuel Czuber and
Ludwig von Tetmajer
Ludwig von Tetmajer (14 July 1850, Krompachy, Upper Hungary - 1 February 1905, Vienna, Austria) was a professor at the Eidgenössischen Polytechnikum, the fore-runner of modern ETH in Zurich. Tetmajer was a pioneer in the development of the res ...
. He then worked for an engineering firm in Vienna, using his knowledge to design structures.
Middle years
Construction 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. The result was particularly evident in the extraordinary design of a reinforced-concrete aqueduct for a hydroelectric power plant in
Sebeș
Sebeș (; German: ''Mühlbach''; Hungarian: ''Szászsebes''; Transylvanian Saxon dialect: ''Melnbach'') is a city in Alba County, central Romania, southern Transylvania.
Geography
The city lies in the Mureș River valley and straddles the ri ...
,
Transylvania
Transylvania ( ro, Ardeal or ; hu, Erdély; german: Siebenbürgen) is a historical and cultural region in Central Europe, encompassing central Romania. To the east and south its natural border is the Carpathian Mountains, and to the west the A ...
, which Milanković designed at the beginning of his career.
He patented a new type of reinforced concrete ribbed ceiling and 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.
Milanković continued to practice civil engineering in Vienna until 1 October 1909 when he was offered the chair of applied mathematics (
rational
Rationality is the quality of being guided by or based on reasons. In this regard, a person acts rationally if they have a good reason for what they do or a belief is rational if it is based on strong evidence. This quality can apply to an abi ...
,
celestial mechanics
Celestial mechanics is the branch of astronomy that deals with the motions of objects in outer space. Historically, celestial mechanics applies principles of physics (classical mechanics) to astronomical objects, such as stars and planets, ...
, and
theoretical physics
Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experim ...
) at the
University of Belgrade
The University of Belgrade ( sr, / ) is a public university in Serbia. It is the oldest and largest modern university in Serbia.
Founded in 1808 as the Belgrade Higher School in revolutionary Serbia, by 1838 it merged with the Kragujevac-ba ...
. Though he continued to pursue his investigations of various problems pertaining to the application of reinforced concrete, he decided to concentrate on fundamental research.
Milanković continued in design and construction work when he moved to
Serbia
Serbia (, ; Serbian: , , ), officially the Republic of Serbia ( Serbian: , , ), is a landlocked country in Southeastern and Central Europe, situated at the crossroads of the Pannonian Basin and the Balkans. It shares land borders with Hu ...
. During 1912, he designed the reinforced bridges in the
Timok valley on the railway line
Niš
Niš (; sr-Cyrl, Ниш, ; names in other languages) is the third largest city in Serbia and the administrative center of the Nišava District. It is located in southern part of Serbia. , the city proper has a population of 183,164, whi ...
-
Knjaževac
Knjaževac ( sr-cyr, Књажевац, ) is a town and municipality located in the Zaječar District of the eastern Serbia. As of 2011, the municipality has a population of 31,491 inhabitants, while the town has 18,404 inhabitants.
The town is si ...
.
Planet's insolation
While studying the works of the contemporaneous climatologist
Julius von Hann
Julius Ferdinand von Hann (23 March 1839 in Wartberg ob der Aist near Linz – 1 October 1921 in Vienna) was an Austrian meteorologist. He is seen as a father of modern meteorology.
Biography
He was educated at the gymnasium of Kremsmünster ...
, Milanković noticed a significant issue, which became one of the major objects of his scientific research: a mystery
ice age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...
. The idea of possible astronomically-related climate changes was first considered by astronomers (
John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint and did botanical wo ...
, 1792–1871) and then postulated by geologists (
Louis Agassiz
Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history.
Spending his early life in Switzerland, he rec ...
, 1807–1873). In parallel, there were also several attempts to explain the climate change by the influence of astronomical forces (the most comprehensive of them was the theory put forward by
James Croll in the 1860s). Milanković studied the works of
Joseph Adhemar
Joseph is a common male given name, derived from the Hebrew Yosef (יוֹסֵף). "Joseph" is used, along with "Josef", mostly in English, French and partially German languages. This spelling is also found as a variant in the languages of the mo ...
whose pioneering theory on the astronomical origins of ice ages were formally rejected by his contemporaries and James Croll whose work was effectively forgotten about even after acceptance by contemporaries such as Charles Darwin. Despite having valuable data on the distribution of ice ages on
Alps
The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...
, 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. But Milanković decided to follow their path and attempt correctly to calculate the magnitude of such influences. Milanković sought the solution of these complex problems in the field of
spherical geometry
300px, A sphere with a spherical triangle on it.
Spherical geometry is the geometry of the two-dimensional surface of a sphere. In this context the word "sphere" refers only to the 2-dimensional surface and other terms like "ball" or "solid sp ...
,
celestial mechanics
Celestial mechanics is the branch of astronomy that deals with the motions of objects in outer space. Historically, celestial mechanics applies principles of physics (classical mechanics) to astronomical objects, such as stars and planets, ...
, and
theoretical physics
Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experim ...
.
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..." 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
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A ...
. He published the first paper on the subject entitled "Contribution to the mathematical theory of climate" in Belgrade on 5 April 1912. His next paper was entitled "''Distribution of the sun radiation on the earth's surface''" and was published on 5 June 1913. He correctly calculates the intensity of
insolation
Solar irradiance is the power per unit area ( surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument.
Solar irradiance is measured in watts per square metre ...
and developed a mathematical theory describing Earth's climate zones. His aim was an integral, mathematically accurate theory which connects thermal regimes of the planets to their movement around the Sun. He wrote: "...such a theory would enable us to go beyond the range of direct observations, not only in space, but also in time... It would allow reconstruction of the Earth's climate, and also its predictions, as well as give us the first reliable data about the climate conditions on other planets." Then he tried to find a
mathematical model
A mathematical model is a description of a system using mathematical concepts and language. The process of developing a mathematical model is termed mathematical modeling. Mathematical models are used in the natural sciences (such as physics, ...
of a cosmic mechanism to describe the Earth's climatic and geological history. He published a paper on the subject entitled "About the issue of the astronomical theory of ice ages" in 1914. But the cosmic mechanism was not an easy problem, and Milanković took three decades to develop an astronomical theory.
At the same time, the
July Crisis
The July Crisis was a series of interrelated diplomatic and military escalations among the major powers of Europe in the summer of 1914, which led to the outbreak of World War I (1914–1918). The crisis began on 28 June 1914, when Gavrilo Pri ...
between the Austro-Hungarian empire and Serbia broke out, which led to
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...
. On 14 June 1914, Milanković married Kristina Topuzović and went on his honeymoon to his native village of
Dalj
Dalj ( sr-Cyrl, Даљ, hu, Dálya, german: Dallia, la, Teutoburgium) is a village on the Danube in eastern Croatia, near the confluence of the Drava and Danube, on the border with Serbia. It is located on the D519 road, south of its intersec ...
in Austro-Hungary, where he heard about the beginning of the War. He was arrested as a citizen of Serbia and was interned by the
Austro-Hungarian
Austria-Hungary, often referred to as the Austro-Hungarian Empire,, the Dual Monarchy, or Austria, was a constitutional monarchy and great power in Central Europe between 1867 and 1918. It was formed with the Austro-Hungarian Compromise of 1 ...
army in
Neusiedl am See
Neusiedl am See (; cs, Nezider; hr, Niuzalj; hu, Nezsider; sk, Nezider) is a town in Burgenland, Austria, and administrative center of the district of Neusiedl am See.
Neusiedl am See is located on the northern shore of the Neusiedler 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:
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
Budapest (, ; ) is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second-largest city on the Danube river; the city has an estimated population o ...
with the right to work.
Immediately after arriving in Budapest, Milanković met the Director of the Library of the
Hungarian Academy of Science
The Hungarian Academy of Sciences ( hu, Magyar Tudományos Akadémia, MTA) is the most important and prestigious learned society of Hungary. Its seat is at the bank of the Danube in Budapest, between Széchenyi rakpart and Akadémia utca. Its ma ...
,
Koloman von Szilly who, as a mathematician, eagerly accepted Milanković and enabled him to work undisturbed in the Academy's library and the Central Meteorological Institute. 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". Milanković calculated that the average temperature in the lower layers the atmosphere on
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...
is and the average surface temperature is . Also, he concluded that: "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 altitudes climate of our Earth." Today it is known that the average temperature is , but that the ground temperatures and air temperatures generally differ. In any case, Milanković theoretically proved that Mars has an extremely harsh climate. In addition to considering Mars, he dealt with the climatic conditions prevailing on
Venus
Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...
and
Mercury. His calculations of the temperature conditions on the neighboring
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
are particularly significant. Milanković knew that
one day on the Moon lasts 15 Earth days, and this is the amount and length of night. Milanković calculated that the surface temperature on the day side of the moon reaches +100.5 °C. Also, he calculated that the temperature during the early morning on the Moon, or before the rise of the Sun over horizon, was −58 °C. Today it is known that the surface temperature on the day side of the Moon reaches +108 °C and that it falls at night to −153 °C.
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
Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. Si ...
under the title "Théorie mathématique des phénomènes thermiques produits par la radiation solaire" (''Mathematical Theory of Heat Phenomena Produced by Solar Radiation''). Immediately after the publication of this book in 1920,
meteorologists
A meteorologist is a scientist who studies and works in the field of meteorology aiming to understand or predict Earth's atmospheric phenomena including the weather. Those who study meteorological phenomena are meteorologists in research, while t ...
recognized it as a significant contribution to the study of contemporary climate. This work was the topic of letter correspondence from 1924 to 1952 between M. Milanković and V. Mišković.
The works of
Vilhelm Bjerknes
Vilhelm Friman Koren Bjerknes ( , ; 14 March 1862 – 9 April 1951) was a Norwegian physicist and meteorologist who did much to found the modern practice of weather forecasting. He formulated the primitive equations that are still in use in num ...
in 1904, and
Lewis Fry Richardson
Lewis Fry Richardson, FRS (11 October 1881 – 30 September 1953) was an English mathematician, physicist, meteorologist, psychologist, and pacifist who pioneered modern mathematical techniques of weather forecasting, and the application of s ...
in 1922 are the foundation of modern
numerical weather prediction
Numerical weather prediction (NWP) uses mathematical models of the atmosphere and oceans to predict the weather based on current weather conditions. Though first attempted in the 1920s, it was not until the advent of computer simulation in th ...
.
Orbital variations and ice age cycles
Milanković's 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
Wladimir Peter Köppen (; russian: Влади́мир Петро́вич Кёппен, translit=Vladimir Petrovich Kyoppen; 25 September 1846 – 22 June 1940) was a Russian-German geographer, meteorologist, climatologist and botanist. After st ...
and from the geophysicist
Alfred Wegener
Alfred Lothar Wegener (; ; 1 November 1880 – November 1930) was a German climatologist, geologist, geophysicist, meteorologist, and polar researcher.
During his lifetime he was primarily known for his achievements in meteorology and ...
. Köppen noted the usefulness of Milanković's theory for
paleoclimatological
Paleoclimatology (American and British English spelling differences, British spelling, palaeoclimatology) is the study of climates for which direct measurements were not taken. As instrumental records only span a tiny part of Earth's history, the ...
researchers. Milanković received a letter on 22 September 1922 from Köppen, who asked him to expand his studies from 130,000 years to 600,000 years. They agreed that summer insolation is a crucial factor for climate. After developing the mathematical machinery enabling him to calculate the insolation in any given geographical latitude and for any annual season, Milanković was ready to start the realization of the mathematical description of climate of the Earth in the past. Milanković spent 100 days doing the calculations and prepared a graph of
solar radiation
Solar irradiance is the power per unit area ( surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument.
Solar irradiance is measured in watts per square metre ...
changes at geographical latitudes of 55°, 60° and
65° north for the past 650,000 years. Milanković believed that these were the latitudes on Earth most sensitive to the change of thermal balance. From that time there is an
anecdote
An anecdote is "a story with a point", such as to communicate an abstract idea about a person, place, or thing through the concrete details of a short narrative or to characterize by delineating a specific quirk or trait. Occasionally humorous ...
, when Milanković's good friend and professor of geography,
Jovan Cvijić
Jovan Cvijić ( sr-cyr, Јован Цвијић, ; 1865 – 16 January 1927) was a Serbian geographer and ethnologist, president of the Serbian Royal Academy of Sciences and rector of the University of Belgrade. Cvijić is considered th ...
, asked him: ''Why do you calculate temperature conditions at the top of the atmosphere, what is the purpose?!''
These curves showed the variations in insolation which correlated with the series of ice ages. Köppen felt that Milanković's theoretical approach to
solar energy
Solar energy is radiant light and heat from the Sun that is harnessed using a range of technologies such as solar power to generate electricity, solar thermal energy (including solar water heating), and solar architecture. It is an essen ...
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
Wladimir Peter Köppen (; russian: Влади́мир Петро́вич Кёппен, translit=Vladimir Petrovich Kyoppen; 25 September 1846 – 22 June 1940) was a Russian-German geographer, meteorologist, climatologist and botanist. After st ...
and his son-in-law
Alfred Wegener
Alfred Lothar Wegener (; ; 1 November 1880 – November 1930) was a German climatologist, geologist, geophysicist, meteorologist, and polar researcher.
During his lifetime he was primarily known for his achievements in meteorology and ...
in 1924.
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
Eccentricity or eccentric may refer to:
* Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal"
Mathematics, science and technology Mathematics
* Off-Centre (geometry), center, in geometry
* Eccentricity (g ...
(100,000-year cycle –
Johannes Kepler
Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws ...
, 1609),
axial tilt
In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orb ...
(41,000-year cycle – from 22,1° to 24,5°; Presently, the Earth's tilt is 23.5° – Ludwig Pilgrim, 1904), and
precession
Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, whereas the third Euler angle defines the rotation itself. In oth ...
(23,000-year cycle –
Hipparchus
Hipparchus (; el, Ἵππαρχος, ''Hipparkhos''; BC) was a Greek astronomer, geographer, and mathematician. He is considered the founder of trigonometry, but is most famous for his incidental discovery of the precession of the e ...
, 130 BC). Each cycle works on a different time-scale and each affects the amount of solar energy received by the planets. Such changes in the geometry of an orbit lead to the changes in the
insolation
Solar irradiance is the power per unit area ( surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument.
Solar irradiance is measured in watts per square metre ...
– the quantity of heat received by any spot at the surface of a planet. These
orbital variations, which are influenced by gravity of the
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
, Sun,
Jupiter
Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousand ...
, and
Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...
, form the basis of the
Milankovitch cycle. His original contribution to celestial mechanics is called Milanković's system of vector elements of planetary orbits. He reduced six
Lagrangean-
Laplacian
In mathematics, the Laplace operator or Laplacian is a differential operator given by the divergence of the gradient of a scalar function on Euclidean space. It is usually denoted by the symbols \nabla\cdot\nabla, \nabla^2 (where \nabla is the ...
elliptical elements to two vectors determining the mechanics of planetary movements. The first specifies the planet's orbital plane, the sense of revolution of the planet, and the orbital ellipse parameter; the second specifies the axis of the orbit in its plane and the orbital eccentricity. By applying those vectors he significantly simplified the calculation and directly obtained all the formulas of the classical theory of secular
perturbations. Milanković, in a simple but original manner, first deduced Newton's law of gravitation from Kepler's laws. Then Milanković treated the two-body and the many-body problems of celestial mechanics. He accepted but corrected the
Le Verrier and
Stockwell
Stockwell is a district in south west London, part of the London Borough of Lambeth, England. It is situated south of Charing Cross. Battersea, Brixton, Clapham, South Lambeth, Oval and Kennington all border Stockwell.
History
The name ...
computation by using newer and more accurate values for the masses of the planets in the solar system.
The
Serbian Academy of Sciences and Arts
The Serbian Academy of Sciences and Arts ( la, Academia Scientiarum et Artium Serbica, sr-Cyr, Српска академија наука и уметности, САНУ, Srpska akademija nauka i umetnosti, SANU) is a national academy and the ...
elected Milanković as a corresponding member in 1920; he became a full member in 1924. The Meteorological service of the
Kingdom of Yugoslavia
The Kingdom of Yugoslavia ( sh-Latn-Cyrl, separator=" / ", Kraljevina Jugoslavija, Краљевина Југославија; sl, Kraljevina Jugoslavija) was a state in Southeast and Central Europe that existed from 1918 until 1941. From 191 ...
became a member of
International Meteorological Organization
The International Meteorological Organization (IMO; 1873–1951) was the first organization formed with the purpose of exchanging weather information among the countries of the world. It came into existence from the realization that weather systems ...
– IMO (founded in
Brussels
Brussels (french: Bruxelles or ; nl, Brussel ), officially the Brussels-Capital Region (All text and all but one graphic show the English name as Brussels-Capital Region.) (french: link=no, Région de Bruxelles-Capitale; nl, link=no, Bruss ...
in 1853 and in
Vienna
en, Viennese
, iso_code = AT-9
, registration_plate = W
, postal_code_type = Postal code
, postal_code =
, timezone = CET
, utc_offset = +1
, timezone_DST ...
in 1873) as a predecessor of present
World Meteorological Organization
The World Meteorological Organization (WMO) is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics.
The WMO originated from the Inter ...
, WMO. Milanković served as a representative of the Kingdom of Yugoslavia there for many years.
Köppen proposed to Milanković on 14 December 1926 to extend his calculations to a million years and to send his results to
Barthel Eberl, a geologist studying the Danube basin, as Eberl's research had unearthed some pre-Ice Ages before over 650,000 years. Eberl published all this in Augsburg in 1930 together with Milanković's curves.
Between 1925 and 1928 Milanković wrote the popular-science book ''
Through Distant Worlds and Times'' in the form of letters to an anonymous woman.
The work discusses the history of astronomy, climatology and science via a series of imaginary visits to various points in space and time by the author and his unnamed companion, encompassing the formation of the Earth, past civilizations, famous ancient and renaissance thinkers and their achievements, and the work of his contemporaries, Köppen and Wegener. In the "letters", Milanković expanded on some of his own theories on astronomy and climatology, and described the complicated problems of celestial mechanics in a simplified manner.
Subsequently, 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
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
and translated into
Russian
Russian(s) refers to anything related to Russia, including:
*Russians (, ''russkiye''), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries
*Rossiyane (), Russian language term for all citizens and peo ...
in 1939. In 1934 Milanković published the book ''Celestial Mechanics''. This textbook used
vector
Vector most often refers to:
*Euclidean vector, a quantity with a magnitude and a direction
*Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism
Vector may also refer to:
Mathematic ...
calculus systematically to solve problems of celestial mechanics.
In the period from 1935 to 1938 Milanković calculated that ice cover depended on changes in insolation. He succeeded in defining the mathematical relationship between summer insolation and the 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.
Geologist
A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althou ...
s received a graph for presenting bordering altitudes of ice covers any period of time during the last 600,000 years.
André Berger and
Jacques Laskar
Jacques Laskar (born 28 April 1955 in Paris) is a French astronomer. He is a research director at the French National Centre for Scientific Research (CNRS), and a member of ''Astronomy and dynamical systems'' of the Institute of Celestial Mechanics ...
later developed this theory further.
Polar wandering
Conversations with
Wegener, the author of
continental drift
Continental drift is the hypothesis that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. The idea of continental drift has been subsumed into the science of pl ...
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
Beno Gutenberg (; June 4, 1889 – January 25, 1960) was a German-American seismologist who made several important contributions to the science. He was a colleague and mentor of Charles Francis Richter at the California Institute of Technolog ...
of
Darmstadt
Darmstadt () is a city in the state of Hesse in Germany, located in the southern part of the Rhine-Main-Area (Frankfurt Metropolitan Region). Darmstadt has around 160,000 inhabitants, making it the fourth largest city in the state of Hesse ...
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. Wegener presented extensive empirical evidence in his scientific work on the 'great events' during the Earth's past. However, one of the main findings that especially preoccupied Wegener and then Milankovitch was the discovery of big
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal is formed when ...
reserves on the
Svalbard
Svalbard ( , ), also known as Spitsbergen, or Spitzbergen, is a Norwegian archipelago in the Arctic Ocean. North of mainland Europe, it is about midway between the northern coast of Norway and the North Pole. The islands of the group rang ...
Islands, in the
Arctic Ocean
The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is known as the coldest of all the oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...
, which could not form at the present latitude of these islands. In the meantime, Wegener died (from
hypothermia
Hypothermia is defined as a body core temperature below in humans. Symptoms depend on the temperature. In mild hypothermia, there is shivering and mental confusion. In moderate hypothermia, shivering stops and confusion increases. In severe ...
or
heart failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, ...
) in November 1930 during his fourth expedition to
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. 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
In Newtonian mechanics, the centrifugal force is an inertial force (also called a "fictitious" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It is directed away from an axis which is paralle ...
of the rotation and can throw the axis off balance and force it to move. Wegener's tragedy additionally motivated Milankovich to persevere in solving the problem of polar wandering.
In the period from 1930 to 1933, Milankovitch worked on the problem of numerical secular rotation pole movements. The Earth as a whole he considered as a
fluid body, which in the case of short-duration forces behaves as a
solid body
thumb , Sound sample of solid-body electric guitar.
A solid-body musical instrument is a string instrument such as a guitar, bass or violin built without its normal sound box and relying on an electromagnetic pickup system to directly detect th ...
, but under an influence behaves as an
elastic body. Using vector analysis he made a mathematical model of the Earth to create a theory of secular motion of the terrestrial poles. He derived the equation of secular trajectory of a terrestrial pole and also the equation of pole motion along this trajectory. 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). He found that the secular pole trajectory depends only on the configuration of the
terrestrial outer shell and the instantaneous pole position on it, more precisely on geometry of the Earth mass. On this basis he could calculate the secular pole trajectory. Also, based on Milanković's model, the continental blocks sink into their underlying "fluidal" base, and slide around, 'aiming to achieve'
isostatic equilibrium
Isostasy (Greek ''ísos'' "equal", ''stásis'' "standstill") or isostatic equilibrium is the state of gravitational equilibrium between Earth's crust (or lithosphere) and mantle such that the crust "floats" at an elevation that depends on its ...
. In his conclusion about this problem, he wrote: For an extraterrestrial observer, the displacement of the pole takes place in such a way that the ... Earth's axis maintains its orientation in space, but the Earth's crust is displaced on its substratum. Milankovitch published his paper on the subject entitled "Numerical trajectory of secular changes of pole’s rotation" in Belgrade in 1932.
At the same time, Milanković wrote four sections of
Beno Gutenberg
Beno Gutenberg (; June 4, 1889 – January 25, 1960) was a German-American seismologist who made several important contributions to the science. He was a colleague and mentor of Charles Francis Richter at the California Institute of Technolog ...
'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 Köppen is a German surname. Notable people with the surname include:
* Bernd Köppen (born 1951), German pianist and composer
* Carl Köppen (1833-1907), German military advisor in Meiji era Japan
* Edlef Köppen (1893–1939), German author and ...
in 1933. The lecture on the apparent shift of poles was held at a congress of Balkan mathematicians in
Athens
Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital and largest city of Greece. With a population close to four million, it is also the seventh largest city in the European Union. Athens dominates a ...
in 1934. That same year, Milanković published an article dedicated to the work Alfred Wegener under titled "Moving of the Earth's Poles – A Memory to Alfred Wegener".
Milankovitch's work on the trajectory of poles was well accepted only by Köppen's associates, because most of the scientific community was skeptical about Wegener and Milankovic's new theories. Later, in the 1950s and 1960s, development of the new scientific discipline in
geophysics
Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' so ...
known as
palaeomagnetism led to the key evidence on the basis of studying the records of
Earth's magnetic field
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magneti ...
in rocks over geological time. Paleomagnetic evidence, both
reversals and polar wandering data, led the revival of the theories of
continental drift
Continental drift is the hypothesis that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. The idea of continental drift has been subsumed into the science of pl ...
and its transformation into
plate tectonics
Plate tectonics (from the la, label= Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of larg ...
in the 1960s and 1970s. Unlike Milankovic's
linear
Linearity is the property of a mathematical relationship ('' function'') that can be graphically represented as a straight line. Linearity is closely related to '' proportionality''. Examples in physics include rectilinear motion, the linear ...
trajectory of poles, palaeomagnetism reconstructed the path of the poles over geological history to show the
nonlinear
In mathematics and science, a nonlinear system is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathematicians, and many oth ...
trajectory.
Later life
To collect his scientific work on the theory of solar radiation that was scattered in many books and papers, 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
Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term was coined and named after Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he hypot ...
.
Milanković spent two years arranging and writing the "Canon". The manuscript was submitted to print on 2 April 1941 – four days before the
attack of Nazi Germany and its allies on the Kingdom of Yugoslavia. In the
bombing of Belgrade on 6 April 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 15 May 1941, two German officers and geology students came to Milanković in his house and brought greetings from Professor of
Freiburg
Freiburg im Breisgau (; abbreviated as Freiburg i. Br. or Freiburg i. B.; Low Alemannic: ''Friburg im Brisgau''), commonly referred to as Freiburg, is an independent city in Baden-Württemberg, Germany. With a population of about 230,000 (as o ...
. 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 in 1941 by the
Royal Serbian Academy, 626 pages in quarto, and was printed in
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
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"
# "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.
]
History of science
After the war, Milanković was vice president of the Serbian Academy of Sciences
The Serbian Academy of Sciences and Arts ( la, Academia Scientiarum et Artium Serbica, sr-Cyr, Српска академија наука и уметности, САНУ, Srpska akademija nauka i umetnosti, SANU) is a national academy and the ...
(1948–1958) and became a member of the Commission 7 for celestial mechanics
Celestial mechanics is the branch of astronomy that deals with the motions of objects in outer space. Historically, celestial mechanics applies principles of physics (classical mechanics) to astronomical objects, such as stars and planets, ...
in the International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
in 1948. In the same year, he became a member of the Italian Institute of Paleontology
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...
. In November 1954, fifty years after receiving his original diploma, he received the Golden Doctor's diploma from the Technical University of Vienna. In 1955, he was also elected to the German Academy of Naturalists "Leopoldina" in Halle Halle may refer to:
Places Germany
* Halle (Saale), also called Halle an der Saale, a city in Saxony-Anhalt
** Halle (region), a former administrative region in Saxony-Anhalt
** Bezirk Halle, a former administrative division of East Germany
** Hal ...
, Saxony-Anhalt
Saxony-Anhalt (german: Sachsen-Anhalt ; nds, Sassen-Anholt) is a state of Germany, bordering the states of Brandenburg, Saxony, Thuringia and Lower Saxony. It covers an area of
and has a population of 2.18 million inhabitants, making i ...
.
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
A stroke is a disease, medical condition in which poor cerebral circulation, blood flow to the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemorr ...
and died in Belgrade
Belgrade ( , ;, ; names in other languages) is the capital and largest city in Serbia. It is located at the confluence of the Sava and Danube rivers and the crossroads of the Pannonian Plain and the Balkan Peninsula. Nearly 1,166,763 mi ...
in 1958. He is buried in his family cemetery in Dalj
Dalj ( sr-Cyrl, Даљ, hu, Dálya, german: Dallia, la, Teutoburgium) is a village on the Danube in eastern Croatia, near the confluence of the Drava and Danube, on the border with Serbia. It is located on the D519 road, south of its intersec ...
.
Legacy
After Milanković's death, 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
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
Program for Scientific Translations, and was published by the U.S. Department of Commerce and the National Science Foundation
The National Science Foundation (NSF) is an independent agency of the United States government that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National ...
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 Prediction, known as CLIMAP, was a major research project of the 1970s and 80s to produce a map of climate conditions during the Last Glacial Maximum. The project was funded by the National Science F ...
(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
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object.
For a satellite orbiting the Ea ...
of the Earth's axis of rotation
Rotation, or spin, is the circular movement of an object around a '' central axis''. A two-dimensional rotating object has only one possible central axis and can rotate in either a clockwise or counterclockwise direction. A three-dimensional ...
and its precession
Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, whereas the third Euler angle defines the rotation itself. In oth ...
. 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. In 1989, the project SPECMAP (Spectral Mapping Project), showed that the climate changes are responses to changes in solar radiation of each of the three astronomical cycles.
In 1999, it was shown that variations in the isotopic composition of oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...
in the sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...
s at the bottom of the ocean follow Milankovitch theory. There are other recent studies that indicate the validity of the original Milankovitch theory. Although orbital forcing of Earth's climate is well accepted, the details of how orbitally-induced changes in insolation affect climate are debated.
On light
Milanković authored two papers on relativity. He wrote his first paper "On the theory of Michelson's experiment" in 1912. He was doing research in this theory from 1924. His papers on this matter were on special relativity and both are on the Michelson experiment (now known as the Michelson–Morley experiment
The Michelson–Morley experiment was an attempt to detect the existence of the luminiferous aether, a supposed medium permeating space that was thought to be the carrier of light waves. The experiment was performed between April and July 188 ...
) which produced strong evidence against aether theory. In the light of the Michelson experiment he discussed on the validity of the second postulate of special theory of relativity
In physics, the special theory of relativity, or special relativity for short, is a scientific theory regarding the relationship between space and time. In Albert Einstein's original treatment, the theory is based on two postulates:
# The law ...
, that the speed of light
The speed of light in vacuum, commonly denoted , is a universal physical constant that is important in many areas of physics. The speed of light is exactly equal to ). According to the special theory of relativity, is the upper limit fo ...
is the same in every reference frame.
Revised Julian calendar
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 church
The Eastern Orthodox Church, also called the Orthodox Church, is the second-largest Christian church, with approximately 220 million baptized members. It operates as a communion of autocephalous churches, each governed by its bishops via ...
es adopted the calendar;[. This is a translation of the paper by Milankovitch in ''Astronomische Nachrichten''.] 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
Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical f ...
and atomic clocks beginning in the 1930s that this could be proven and quantified. 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.
Awards and honors
In honour of his achievements in astronomy, an impact crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...
on the far side of the Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
was given the name Milankovic at the 14th IAU General Assembly in 1970. His name is also given to a crater on Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...
at the 15th IAU General Assembly in 1973. Since 1993 the Milutin Milankovic Medal
The Milutin Milankovic Medal is an annual award in Earth science presented by the European Geosciences Union (EGU). The award was introduced in 1993 by the European Geophysical Society (EGS). After a merger with the European Union of Geosciences ...
has been awarded by the European Geophysical Society
The European Geosciences Union (EGU) is a non-profit international union in the fields of Earth, planetary, and space sciences whose vision is to "realise a sustainable and just future for humanity and for the planet." The organisation has headqu ...
(called the EGU since 2003) for contributions in the
area of long-term climate and modeling. A main belt asteroid discovered in 1936 has also been dubbed 1605 Milankovitch. At NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeedin ...
, 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. He was awarded Order of Saint Sava
The Royal Order of St. Sava is an Order of merit, first awarded by the Kingdom of Serbia in 1883 and later by the Kingdom of Serbs, Croats and Slovenes, and the Kingdom of Yugoslavia. It was awarded to nationals and foreigners for meritorious ach ...
and Order of the Yugoslav Crown.
In popular culture
*''Milutin Milanković – A Traveler Through Distant Worlds and Times'', a 2007 documentary film
A documentary film or documentary is a non-fictional motion-picture intended to "document reality, primarily for the purposes of instruction, education or maintaining a historical record". Bill Nichols has characterized the documentary in te ...
based on the biography of Milutin Milankovitch, directed by Dušan Vuleković.Milutin Milanković – A Traveler Through Distant Worlds and Times
on YouTube
YouTube is a global online video sharing and social media platform headquartered in San Bruno, California. It was launched on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim. It is owned by Google, and is the second mo ...
Selected works
* ''Théorie mathématique des phénomènes thermiques produits par la radiation solaire'', XVI, 338 S. – Paris: Gauthier-Villars, 1920
* ''Reforma julijanskog kalendara.'' Srpska Kr. Akad. Pos. Izda’na 47: 52 S., Beograd: Sv. Sava, 1923
* ''Mathematische Klimalehre und astronomische Theorie der Klimaschwankungen.'' In: Köppen, W.; Geiger R. (Hrsg.): Handbuch der Klimatologie, Bd. 1: Allgemeine Klimalehre, Berlin: Borntraeger, 1930
* ''Mathematische Klimalehre.'' In: Gutenberg, B. (Hrsg.) Handbuch der Geophysik, Berlin: Borntraeger, 1933
* ''Durch ferne Welten und Zeiten, Briefe eines Weltallbummlers.'' 389 S. – Leipzig: Koehler & Amelang, 1936
* ''Kanon der Erdbestrahlung und seine Anwendung auf das Eiszeitenproblem.'' Académie royale serbe. Éditions speciales; 132
ielm. 133 XX, 633, Belgrad, 1941
* ''Canon of insolation and the ice-age problem.'' English translation by the Israel Program for Scientific Translations, published for the U.S. Department of Commerce and National Science Foundation, Washington, D.C.: 633 S., 1969
* ''Canon of Insolation and the Ice-Age Problem.'' Pantic, N. (Hrsg.), Beograd: Zavod Nastavna Sredstva, 634 S., 1998
See also
*
History of climate change science
The history of the scientific discovery of climate change began in the early 19th century when ice ages and other natural changes in paleoclimate were first suspected and the natural greenhouse effect was first identified. In the late 19th centu ...
*
Milutin Milanković Cultural and Science Center
References
External links
Ice Age – Milankovitch Cycles – National Geographic ChannelThree variables known as the Milankovitch Cycles affect how and when Earth enters an ice age or global warming.
Milanković’s Analysis of Newton’s Law of Universal GravitationMilankovitch theory hits and missesNASA Earth Observatory article in the "on the shoulders of giants" series
{{DEFAULTSORT:Milankovic, Milutin
1879 births
1958 deaths
People from Dalj
People from the Kingdom of Serbia
Members of the Serbian Orthodox Church
Members of the Serbian Academy of Sciences and Arts
Recipients of the Order of St. Sava
Recipients of the Order of the Yugoslav Crown
Serbian scientists
Serbian astronomers
Serbian climatologists
Serbian geophysicists
Serbian mathematicians
Serbian civil engineers
Serbian writers
Serbian non-fiction writers
Serbian science fiction writers
TU Wien alumni
University of Belgrade faculty
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20th-century Serbian people
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