# Spiru Haret

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Romanian mathematician, astronomer and politician

For the village in Brăila County, see [Berteștii de Jos](/source/Berte%C8%99tii_de_Jos). For an institution, see [Spiru Haret University](/source/Spiru_Haret_University).

Spiru Haret Born Spiridon Haret (1851-02-15)15 February 1851 Iași, Moldavia Died 17 December 1912(1912-12-17) (aged 61) Bucharest, Kingdom of Romania Resting place Bellu Cemetery, Bucharest, Romania Education Saint Sava National College Alma mater University of Bucharest University of Paris Known for N-body problem Romanian education system Spouse Ana Popescu ​ (m. 1883)​ Scientific career Fields Mathematics, Astronomy Institutions University of Bucharest School of Bridges and Roads Thesis Sur l’invariabilité des grandes axes des orbites planétaires (1878) Doctoral advisor Victor Puiseux Minister of Religious Affairs and Public Instruction In office 31 March 1897 – 30 March 1899 Prime Minister Dimitrie Sturdza Preceded by George Mârzescu Succeeded by Take Ionescu In office 14 February 1901 – 20 December 1904 Prime Minister Dimitrie Sturdza Preceded by Constantin C. Arion Succeeded by Mihail Vlădescu In office 12 March 1907 – 28 December 1910 Prime Minister Dimitrie Sturdza Ion I. C. Brătianu Preceded by Constantin Istrati Succeeded by Constantin C. Arion Interior Minister In office 13 December 1904 – 20 December 1904 Prime Minister Dimitrie Sturdza Preceded by Vasile Lascăr Succeeded by Gheorghe Grigore Cantacuzino

**Spiru C. Haret** (Romanian pronunciation: [\[ˈspiru haˈret\]](https://en.wikipedia.org/wiki/Help:IPA/Romanian); 15 February 1851 – 17 December 1912) was a [Romanian](/source/Romania) [mathematician](/source/Mathematician), [astronomer](/source/Astronomer), and [politician](/source/Politician). He made a fundamental contribution to the [*n*-body problem](/source/N-body_problem) in [celestial mechanics](/source/Celestial_mechanics) by proving that using a [third degree approximation](/source/Orders_of_approximation) for the disturbing forces implies instability of the [major axes](/source/Semi-major_and_semi-minor_axes) of the orbits, and by introducing the concept of *secular perturbations* in relation to this.

As a politician, during his three terms as [Minister of Education](/source/Education_minister), Haret ran deep reforms, building the modern Romanian education system. He was made a full [member of the Romanian Academy](/source/List_of_members_of_the_Romanian_Academy) in 1892.

He also founded the [Bucharest Astronomical Observatory](/source/Bucharest_Astronomical_Observatory), appointing [Nicolae Coculescu](https://en.wikipedia.org/w/index.php?title=Nicolae_Coculescu&action=edit&redlink=1) [[ro](https://ro.wikipedia.org/wiki/Nicolae_Coculescu)] as its first director. The crater [Haret](/source/Haret_(crater)) on the Moon is named after him.

## Life

Haret was born in [Iași](/source/Ia%C8%99i), [Moldavia](/source/Moldavia), to Constantin and Smaranda Haret,[1] who were of [Armenian](/source/Armenians_in_Romania) origin.[2] His baptismal record listed his name as Spiridon Haret.[1] He started his studies in [Dorohoi](/source/Dorohoi) Iași, and in 1862 moved to [Saint Sava High School](/source/Saint_Sava_National_College) in [Bucharest](/source/Bucharest).[3] He showed an early talent for mathematics, publishing two textbooks (one in [algebra](/source/Algebra) and one in [trigonometry](/source/Trigonometry)) when he was still a high school student. In 1869 he entered the [University of Bucharest](/source/University_of_Bucharest), where he studied [physics](/source/Physics) and [mathematics](/source/Mathematics). In 1870, while a student in his second term, he became teacher of mathematics at the [Nifon Seminary](https://en.wikipedia.org/w/index.php?title=Nifon_Seminary&action=edit&redlink=1) in [Bucharest](/source/Bucharest), but quit the following year in order to continue his studies. In 1874, at age 23, he graduated with a degree in physics and mathematics.

After graduation, Haret won a scholarship competition organized by [Titu Maiorescu](/source/Titu_Maiorescu) and went to [Paris](/source/Paris) in order to study mathematics at the [Sorbonne](/source/University_of_Paris). There he earned a mathematics diploma in 1875 and a physics diploma in 1876. Two years later (on 18 January 1878), he earned his [Ph.D.](/source/Doctor_of_Philosophy) by defending his thesis, *Sur l’invariabilité des grandes axes des orbites planétaires* (*On the invariability of the major axis of planetary orbits*),[4] in front of examiners led by [Victor Puiseux](/source/Victor_Puiseux), his Ph.D. advisor.[5] In this work he proved a result fundamental for the *n*-body problem in astronomy, the thesis being published in volume 18 of *Annales de l'[Observatoire de Paris](/source/Paris_Observatory)*. Haret was the first Romanian to obtain a Ph.D. degree in Paris.

After his return to Romania in 1878, Haret largely abandoned scientific research and dedicated the rest of his life to improving Romanian education, which was heavily underdeveloped at the time, both as professor and as politician. He was appointed professor of [rational mechanics](/source/Classical_mechanics) at the Faculty of Science of the University of Bucharest.[4] The next year (1879), Haret became a correspondent member of the [Romanian Academy](/source/Romanian_Academy), receiving full membership in 1892. He kept the professorship at the Faculty of Science until his retirement in 1910, when he was followed as professor of mechanics by [Dimitrie Pompeiu](/source/Dimitrie_Pompeiu). From 1882 he was also a professor of [analytical geometry](/source/Analytical_geometry) at the [School of Bridges and Roads](/source/Politehnica_University_of_Bucharest) in Bucharest. After retirement, Haret occasionally lectured at the informal *People's University*.

Haret was the [Minister of Public Education](/source/Education_minister) in three [liberal](/source/Liberalism_and_radicalism_in_Romania) governments, between 1897 and 1899, 1901–1904, and 1907–1910. As Minister of Education he ran a complete reform, basically building the modern [Romanian education system](/source/Education_in_Romania).

The folk song "[Cântă cucu-n Bucovina](/source/C%C3%A2nt%C4%83_cucu-n_Bucovina)" ("Sings the Cuckoo in Bukovina") was composed in 1904 by [Constantin Mandicevschi](https://en.wikipedia.org/w/index.php?title=Constantin_Mandicevschi&action=edit&redlink=1) [[de](https://de.wikipedia.org/wiki/Constantin_Mandicevschi); [ru](https://ru.wikipedia.org/wiki/%D0%9C%D0%B0%D0%BD%D0%B4%D1%8B%D1%87%D0%B5%D0%B2%D1%81%D0%BA%D0%B8%D0%B9,_%D0%9A%D0%BE%D0%BD%D1%81%D1%82%D0%B0%D0%BD%D1%82%D0%B8%D0%BD); [uk](https://uk.wikipedia.org/wiki/%D0%9C%D0%B0%D0%BD%D0%B4%D0%B8%D1%87%D0%B5%D0%B2%D1%81%D1%8C%D0%BA%D0%B8%D0%B9_%D0%9A%D0%BE%D1%81%D1%82%D1%8F%D0%BD%D1%82%D0%B8%D0%BD_%D0%92%D0%B0%D1%81%D0%B8%D0%BB%D1%8C%D0%BE%D0%B2%D0%B8%D1%87)] at Haret's request for commemorating the 400th anniversary of the death of [Prince of Moldavia](/source/List_of_rulers_of_Moldavia) [Stephen the Great](/source/Stephen_the_Great).[6]

In January 1883, he married in [Buzău](/source/Buz%C4%83u) a local, Ana Popescu, 15 years his junior. The two had a son, Ion, who died at age 1, and later adopted a child, Mihai. Haret died in Bucharest in 1912 of cancer, and was buried in the city's [Bellu Cemetery](/source/Bellu_Cemetery); Ana Haret died in 1941, aged 74.[1]

## Scientific activity

Haret's major scientific contribution was made in 1878, in his Ph.D. thesis *Sur l’invariabilité des grandes axes des orbites planétaires*. At the time it was known that planets disturb each other's orbits, thus deviating from the [elliptic](/source/Ellipse) motion described by [Johannes Kepler](/source/Johannes_Kepler)’s [First Law](/source/Kepler's_laws_of_planetary_motion). [Pierre Laplace](/source/Pierre_Laplace) (in 1773) and [Joseph Louis Lagrange](/source/Joseph_Louis_Lagrange) (in 1776) had already studied the problem, both of them showing that the major axes of the orbits are stable, by using a first degree approximation of the perturbing forces. In 1808 [Siméon Denis Poisson](/source/Sim%C3%A9on_Denis_Poisson) had proved that the stability also holds when using second degree approximations. In his thesis, Haret proved by using third degree approximations that the axes are not stable as previously believed, but instead feature a time variability, which he called *secular perturbations*. This result implies that planetary motion is not absolutely stable. [Henri Poincaré](/source/Henri_Poincar%C3%A9) considered this result *a great surprise* and continued Haret’s research, which eventually led him to the creation of [chaos theory](/source/Chaos_theory). Haret established the instability of the model of the *n*-body problem assuming frequencies to be incommensurable; Poincaré also took into account [commensurabilities](/source/Commensurability_(astronomy)), and using [generalized Fourier series](/source/Generalized_Fourier_series) (which generate [quasi-periodic](/source/Quasiperiodicity) solutions), he proved the divergence of these series (which means instability), thus confirming Haret’s result.[7] [Félix Tisserand](/source/F%C3%A9lix_Tisserand) recommended the extension of Haret's method to other astronomic problems and, much later, in 1955, [Jean Meffroy](https://en.wikipedia.org/w/index.php?title=Jean_Meffroy&action=edit&redlink=1) restarted Haret’s research using new techniques.[8]

Soon after his return to Romania, Haret abandoned research, focusing for the rest of his life on teaching and, as Minister of Education, on the reform of the education system. He only published an article on the [secular acceleration](/source/Tidal_acceleration) of the Moon in 1880 and one on [Jupiter](/source/Jupiter)’s [Great Red Spot](/source/Great_Red_Spot) (1912).[4]

Bust of Spiru Haret by [Dimitrie Paciurea](/source/Dimitrie_Paciurea)

In 1910 he published *Social mechanics*, which used mathematics to explain social behaviour (somehow anticipating the fictional "[psychohistory](/source/Psychohistory_(fictional))" branch of mathematics developed by [Hari Seldon](/source/Hari_Seldon), the fictional character of [Isaac Asimov](/source/Isaac_Asimov)'s [*Foundation*](/source/The_Foundation_Series), published 40 years later).

## References

1. ^ [***a***](#cite_ref-Ana_1-0) [***b***](#cite_ref-Ana_1-1) [***c***](#cite_ref-Ana_1-2) Iulian Bunila (14 October 2015). ["Femeia care i-a sucit mințile lui Spiru Haret. Primul român cu doctorat în matematici la Sorbona s-a îndrăgostit de o adolescentă cu 15 ani mai tânără"](https://adevarul.ro/locale/buzau/femeia-i-a-sucit-mintile-spiru-haret-roman-doctorat-matematici-sorbona-s-a-indragostit-adolescenta-15-ani-mai-tanara-1_561d0b34f5eaafab2c9e0e99/index.html). *[Adevărul](/source/Adev%C4%83rul)* (in Romanian). Retrieved 21 February 2022.

1. **[^](#cite_ref-ziare_2-0)** Camelia Badea (10 February 2013). ["Mari politicieni români: Spiru Haret, reformatorul societății românești"](https://ziare.com/scoala/invatamant/mari-politicieni-romani-spiru-haret-reformatorul-societatii-romanesti-1217833). *ziare.com* (in Romanian). Retrieved 21 February 2022.

1. **[^](#cite_ref-fse_3-0)** ["Despre Spiru Haret"](https://www.fsespiruharet.ro/despre-spiru-haret/). *www.fsespiruharet.ro* (in Romanian). Federația Sindicatelor din Educație "Spiru Haret". Retrieved 21 February 2022.

1. ^ [***a***](#cite_ref-Mac_4-0) [***b***](#cite_ref-Mac_4-1) [***c***](#cite_ref-Mac_4-2) O'Connor, John J.; [Robertson, Edmund F.](/source/Edmund_F._Robertson), ["Spiru Haret"](https://mathshistory.st-andrews.ac.uk/Biographies/Haret.html), *[MacTutor History of Mathematics Archive](/source/MacTutor_History_of_Mathematics_Archive)*, [University of St Andrews](/source/University_of_St_Andrews)

1. **[^](#cite_ref-5)** [Spiru Haret](https://mathgenealogy.org/id.php?id=196373) at the [Mathematics Genealogy Project](/source/Mathematics_Genealogy_Project)

1. **[^](#cite_ref-6)** ["Constantin Mandicevschi – autorul renumitului cântec românesc "Cântă cucu-n Bucovina""](https://timpul.md/articol/constantin-mandicevschi-autorul-renumitului-cantec-romanesc-canta-cucu-n-bucovina-113263.html). *Timpul* (in Romanian). 24 July 2017.

1. **[^](#cite_ref-obspm_7-0)** Magda Stavinschi; Vasile Mioc (2004), "Astronomical Researches in Poincaré's and Romanian Works", in Nicole Capitaine (ed.), [*Journées 2004*](https://syrte.obspm.fr/journees2004/pdf/ProcJournees04.pdf) (PDF), [Paris Observatory](/source/Paris_Observatory), pp. 155–156, [ISBN](/source/ISBN_(identifier)) [2-901057-51-9](https://en.wikipedia.org/wiki/Special:BookSources/2-901057-51-9)

1. **[^](#cite_ref-8)** Jean Meffroy (1955). ["Contribution a L'Étude de la Stabilité du Systéme Solaire"](https://adsabs.harvard.edu/full/1955BuAst..19..197M). *[Bulletin Astronomique](/source/Astronomy_%26_Astrophysics)* (in French). **19**: 197–221. [Bibcode](/source/Bibcode_(identifier)):[1955BuAst..19..197M](https://ui.adsabs.harvard.edu/abs/1955BuAst..19..197M).

- Ion Bulei (1990), *Atunci când veacul se năștea... lumea româneasca 1900–1908* [*When the century was born... the Romanian world 1900–1908*] (in Romanian), Editura Eminescu, pp. 82–96

## External links

Wikimedia Commons has media related to [Spiru Haret](https://commons.wikimedia.org/wiki/Category:Spiru_Haret).

- [Constantin Schifirneț](/source/Constantin_Schifirne%C8%9B), ["Spiru Haret, reformatorul societății românești"](https://www.academia.edu/4394842) [Spiru Haret, the reformer of Romanian society], *Studiu Introductiv la Operele Lui Spiru Haret, Vol. I, Editura Comunicare.ro, 2009, Pp. 13-42* (in Romanian)

- [Constantin Schifirneț](/source/Constantin_Schifirne%C8%9B) (2014), ["Spiru Haret, Education and School Legislation Reform"](http://www.revistadesociologie.ro/pdf-uri/nr.3-4-2014/07-CSchifirnet.pdf) (PDF), *Revista română de sociologie*, **XXV** (3–4): 311–326

- Sorin-Avram Vîrtop (2019), ["Beyond mythology and tradition of an educational reform or about the realism of Spiru Haret's educational reform (1851–1912)"](http://www.utgjiu.ro/revista/dppd/pdf/2019-02/03_VIRTOP.pdf) (PDF), *Analele Universității "Constantin Brâncuși" din Târgu Jiu*, **2** (2)

- ["Spiru Haret"](http://bsclupan.asm.md/?lng=0&action=show&cat=91&obj=176). *bsclupan.asm.md* (in Romanian). [Andrei Lupan Central Scientific Library](https://en.wikipedia.org/w/index.php?title=Andrei_Lupan_Central_Scientific_Library&action=edit&redlink=1) [[ro](https://ro.wikipedia.org/wiki/Biblioteca_%C8%98tiin%C8%9Bific%C4%83_Central%C4%83_%E2%80%9EAndrei_Lupan%E2%80%9D_a_Academiei_de_%C8%98tiin%C8%9Be_a_Moldovei)]. Retrieved 21 February 2022.

- ["Liga Spiru Haret"](https://web.archive.org/web/20090411111051/http://www.ligaspiruharet.ro/). Archived from [the original](http://www.ligaspiruharet.ro/) on 11 April 2009.

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v t e Interior ministers of Romania United Principalities Principality of Romania B. Catargiu Arsache N. Kretzulescu Kogălniceanu Bosianu Florescu D. Ghica L. Catargiu I. Ghica I. C. Brătianu Ș. Golescu A. Arion A. Golescu Epureanu Vernescu C. A. Rosetti Stolojan Teriachiu Stătescu Kingdom of Romania Chițu Mihai Nacu T. Rosetti Știrbei Manu Fleva Sturdza Lascăr Pherekyde Cantacuzino Olănescu Aurelian Pallade Haret I. I. C. Brătianu Marghiloman C. Arion T. Ionescu Morțun Constantinescu Sărățeanu Văitoianu Mârzescu Averescu Vlad Lupu Argetoianu Cămărășescu Goga Știrbey Duca Vaida-Voevod Popovici Mihalache Iorga Mironescu Inculeț Iuca Tătărescu Franasovici Călinescu Marinescu Ottescu Ghelmegeanu David Popescu Petrovicescu Dumitru Popescu Aldea Penescu Sănătescu Rădescu Georgescu Socialist Republic Georgescu Drăghici Ștefan Drăghici Onescu Stănescu Bobu Coman Homoștean Postelnicu Romania since 1989 Chițac Ursu Babiuc Dănescu Tărăcilă Dejeu C. Ionescu Rus Săniuță Blaga David Oprea Dragnea Nica Blaga Igaș Berca Rus Dușa Stroe Oprea Tobă Tudorache Dan Moga Vela Bode

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Adapted from the Wikipedia article [Spiru Haret](https://en.wikipedia.org/wiki/Spiru_Haret) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Spiru_Haret?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.