Ivan Supek (8 April 1915 – 5 March 2007) was a

Croatia , image_flag = Flag of Croatia.svg , image_coat = Coat of arms of Croatia.svg , anthem = "Lijepa naša domovino"("Our Beautiful Homeland") , image_map = , map_caption = , capit ...

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...

philosopher A philosopher is a person who practices or investigates philosophy. The term ''philosopher'' comes from the grc, φιλόσοφος, , translit=philosophos, meaning 'lover of wisdom'. The coining of the term has been attributed to the Greek th ...

writer A writer is a person who uses written words in different writing styles and techniques to communicate ideas. Writers produce different forms of literary art and creative writing such as novels, short stories, books, poetry, travelogues, p ...

playwright A playwright or dramatist is a person who writes plays. Etymology The word "play" is from Middle English pleye, from Old English plæġ, pleġa, plæġa ("play, exercise; sport, game; drama, applause"). The word "wright" is an archaic English ...

peace activist A peace movement is a social movement which seeks to achieve ideals, such as the ending of a particular war (or wars) or minimizing inter-human violence in a particular place or situation. They are often linked to the goal of achieving world pea ...

and

humanist Humanism is a philosophical stance that emphasizes the individual and social potential and agency of human beings. It considers human beings the starting point for serious moral and philosophical inquiry. The meaning of the term "human ...

Early years and education

Supek was born in

Zagreb Zagreb ( , , , ) is the capital (political), capital and List of cities and towns in Croatia#List of cities and towns, largest city of Croatia. It is in the Northern Croatia, northwest of the country, along the Sava river, at the southern slop ...

, Croatia (still nominally under

Austria-Hungary 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 ...

). During his high school days, he organized a local section of the

Young Communist League of Yugoslavia , SKOJ mk, Сојуз на комунистичката младина на Југославија, СКМЈ sl, Zveza komunistične mladine Jugoslavije, ZKMJ , colorcode = red , founded = 1919 , dissolved = 1948 , succeeded by = League of S ...

at his school, and was a member of the League until the Hitler-Stalin Pact. On one occasion, he secretly smuggled a briefcase to a man in Vienna he later found to be

Josip Broz Tito Josip Broz ( sh-Cyrl, Јосип Броз, ; 7 May 1892 – 4 May 1980), commonly known as Tito (; sh-Cyrl, Тито, links=no, ), was a Yugoslav communist revolutionary and statesman, serving in various positions from 1943 until his deat ...

. After finishing grammar school in

in 1934, he continued pursuing his education 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 ...

for a brief period, then moved to

Zürich Zürich () is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zürich. It is located in north-central Switzerland, at the northwestern tip of Lake Zürich. As of January 2020, the municipality has 43 ...

studying

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary i ...

and

philosophy Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. Some ...

. Increasingly interested in quantum physics and its philosophical consequences, he moved to

Leipzig Leipzig ( , ; Upper Saxon: ) is the most populous city in the German state of Saxony. Leipzig's population of 605,407 inhabitants (1.1 million in the larger urban zone) as of 2021 places the city as Germany's eighth most populous, as wel ...

where in 1940 he obtained his PhD in physics under

Werner Heisenberg Werner Karl Heisenberg () (5 December 1901 – 1 February 1976) was a German theoretical physicist and one of the main pioneers of the theory of quantum mechanics. He published his work in 1925 in a breakthrough paper. In the subsequent series ...

. He worked on problems of superconductivity, but ultimately his doctoral dissertation was on electrical conductivity in metals in low temperatures. In March 1941 he was arrested by the

Gestapo The (), abbreviated Gestapo (; ), was the official secret police of Nazi Germany and in German-occupied Europe. The force was created by Hermann Göring in 1933 by combining the various political police agencies of Prussia into one organi ...

for being involved in antifascist activity and held in prison for many months. His professors,

Heisenberg Werner Karl Heisenberg () (5 December 1901 – 1 February 1976) was a German theoretical physicist and one of the main pioneers of the theory of quantum mechanics. He published his work in 1925 in a breakthrough paper. In the subsequent series ...

, Hund and von Weizsäcker intervened to release him from prison. Immediately after being released, instead of returning to Leipzig, he went back to

Independent State of Croatia The Independent State of Croatia ( sh, Nezavisna Država Hrvatska, NDH; german: Unabhängiger Staat Kroatien; it, Stato indipendente di Croazia) was a World War II-era puppet state of Nazi Germany and Fascist Italy. It was established in p ...

and joined the

communist Communism (from Latin la, communis, lit=common, universal, label=none) is a far-left sociopolitical, philosophical, and economic ideology and current within the socialist movement whose goal is the establishment of a communist society, a s ...

antifascist Anti-fascism is a political movement in opposition to fascist ideologies, groups and individuals. Beginning in European countries in the 1920s, it was at its most significant shortly before and during World War II, where the Axis powers were ...

movement. He would not return to physics research again, focusing on his philosophical and literary work.

Public activity

Supek was a proponent of total and unconditional nuclear disarmament, having already in 1944, fourteen months before the

bombing of Hiroshima The United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August 1945, respectively. The two bombings killed between 129,000 and 226,000 people, most of whom were civilians, and remain the onl ...

warned on the danger of misuse of

atomic energy Atomic energy or energy of atoms is energy carried by atoms. The term originated in 1903 when Ernest Rutherford began to speak of the possibility of atomic energy. Isaac Asimov, ''Atom: Journey Across the Sub-Atomic Cosmos'', New York:1992 Plume, ...

. In 1946 he became a professor of

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 Zagreb The University of Zagreb ( hr, Sveučilište u Zagrebu, ; la, Universitas Studiorum Zagrabiensis) is the largest Croatian university and the oldest continuously operating university in the area covering Central Europe south of Vienna and all of ...

. His main contribution to physics was the discovery of the

differential equation In mathematics, a differential equation is an equation that relates one or more unknown functions and their derivatives. In applications, the functions generally represent physical quantities, the derivatives represent their rates of change, an ...

for

electrical conductivity Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allow ...

at low temperatures. In 1950 he advocated the construction of the

Ruđer Bošković institute The Ruđer Bošković Institute (RBI; hr, Institut Ruđer Bošković, , IRB) is a research institute located in the Šalata neighborhood of Zagreb, Croatia, founded in 1950, which studies the sciences. Description It is the largest Croatian resea ...

in Zagreb and became one of its founders. He was excluded from it in 1958 due to his disagreement with the Yugoslav Federal Commission for Nuclear Energy and his unwillingness to participate in a project for building the atomic bomb (an idea

himself did not like much, and which was subsequently abandoned). After that, he stopped active research in theoretical physics and continued researching philosophy and literature. In 1960 he was accepted into the

Yugoslav Academy of Sciences and Arts The Croatian Academy of Sciences and Arts ( la, Academia Scientiarum et Artium Croatica, hr, Hrvatska akademija znanosti i umjetnosti, abbrev. HAZU) is the national academy of Croatia. HAZU was founded under patronage of the Croatian bishop Jo ...

(since 1991 the

Croatian Academy of Sciences and Arts The Croatian Academy of Sciences and Arts ( la, Academia Scientiarum et Artium Croatica, hr, Hrvatska akademija znanosti i umjetnosti, abbrev. HAZU) is the national academy of Croatia. HAZU was founded under patronage of the Croatian bishop J ...

) of which he was president from 1991 to 1997, and in 1968 he became the rector of the University of Zagreb, serving two terms until 1972, during the turbulent times of the Croatian Spring. In 1960 he founded the Institute for the Philosophy of Science and Peace, as a section of the Yugoslav Academy of Sciences and Arts. The Institute was also a center of the nuclear disarmament movement, the Pugwash Conference for Yugoslavia, of which he was one of the founders and a member of its Permanent Committee. In 1970 he initiated the establishing of the Interuniversity Centre in Dubrovnik (IUC). He was also one of the founders of the international organization World without the Bomb. After numerous disputes and arguments with the government he was interrupted in his public activity in 1971. Among other incidents, he was put on a "black list" because of his involvement in the Croatian Spring movement. In 1976 he signed the Dubrovnik-Philadelphia Statement, with

Philip Noel-Baker Philip John Noel-Baker, Baron Noel-Baker, (1 November 1889 – 8 October 1982), born Philip John Baker, was a British politician, diplomat, academic, athlete, and renowned campaigner for disarmament. He carried the British team flag and won a ...

Ava Helen Pauling Ava Helen Pauling (born Miller; December 24, 1903 – December 7, 1981) was an American human rights activist and wife of Nobel Prize winner Linus Pauling. Throughout her life, she was involved in various social movements including women's right ...

Linus Pauling Linus Carl Pauling (; February 28, 1901August 19, 1994) was an American chemist, biochemist, chemical engineer, peace activist, author, and educator. He published more than 1,200 papers and books, of which about 850 dealt with scientific top ...

Aurelio Peccei Aurelio Peccei (; 4 July 1908 – 14 March 1984), was an Italian industrialist and philanthropist, best known as co-founder with Alexander King and first president of the Club of Rome, an organisation which attracted considerable public atten ...

and Sophia Wadai. He participated at the Philadelphia Congress of World Unity in 1976. He formulated his famous ten humanistic principles, which were more or less repeated at every later peace summit and event. He also established the

International League of Humanists International League of Humanists (ILH) is a non-profit international association of eminent humanists. Its headquarters are in Sarajevo, Bosnia and Herzegovina and its primary objective is promotion of worldwide peace and human rights. Its curr ...

Later years to present

Supek visited and lectured at numerous foreign

universities A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, t ...

. He retired in 1985, but ever since continued his

work. He founded a citizen association, ''Alijansa za treću Hrvatsku'' (Alliance for the third Croatia). He was a critic of globalisation and a

proponent {{Short pages monitor