Tatyana Alexeyevna Afanasyeva-Ehrenfest (; ; 19 November 1876 – 14 April 1964) was a Russian-Dutch mathematician and physicist who made contributions to the fields of

statistical mechanics In physics, statistical mechanics is a mathematical framework that applies statistical methods and probability theory to large assemblies of microscopic entities. Sometimes called statistical physics or statistical thermodynamics, its applicati ...

and statistical thermodynamics with her husband

Paul Ehrenfest Paul Ehrenfest (; 18 January 1880 – 25 September 1933) was an Austrian Theoretical physics, theoretical physicist who made major contributions to statistical mechanics and its relation to quantum physics, quantum mechanics, including the theory ...

Early life

Tatyana Afanasyeva was born in

Kiev Kyiv, also Kiev, is the capital and most populous List of cities in Ukraine, city of Ukraine. Located in the north-central part of the country, it straddles both sides of the Dnieper, Dnieper River. As of 1 January 2022, its population was 2, ...

Ukraine Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the nor ...

, then part of the

Russian Empire The Russian Empire was an empire that spanned most of northern Eurasia from its establishment in November 1721 until the proclamation of the Russian Republic in September 1917. At its height in the late 19th century, it covered about , roughl ...

. Her father was Alexander Afanassjev, a chief engineer on the Imperial Railways, who would bring Tatyana on his travels around the Russian Empire. Her father died while she was still young, so she moved to

St Petersburg Saint Petersburg, formerly known as Petrograd and later Leningrad, is the List of cities and towns in Russia by population, second-largest city in Russia after Moscow. It is situated on the Neva, River Neva, at the head of the Gulf of Finland ...

in Russia to live with her aunt Sonya, and uncle Peter Afanassjev, a professor at the St Petersburg Polytechnic Institute. Afanasyeva attended normal school in St Petersburg with a specialty in mathematics and science. At the time, women were not allowed to attend universities in Russian territory, so after graduating from normal school, Tatyana began studying mathematics and physics at the Women's University in St Petersburg under Orest Chvolson. In 1902, she transferred to

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen (, commonly referred to as Georgia Augusta), is a Public university, public research university in the city of Göttingen, Lower Saxony, Germany. Founded in 1734 ...

in Germany to continue her studies with

Felix Klein Felix Christian Klein (; ; 25 April 1849 – 22 June 1925) was a German mathematician and Mathematics education, mathematics educator, known for his work in group theory, complex analysis, non-Euclidean geometry, and the associations betwe ...

and

David Hilbert David Hilbert (; ; 23 January 1862 – 14 February 1943) was a German mathematician and philosopher of mathematics and one of the most influential mathematicians of his time. Hilbert discovered and developed a broad range of fundamental idea ...

. At the University of Göttingen, Afanasyeva met Paul Ehrenfest. When Ehrenfest discovered that Afanasyeva could not attend a mathematics club meeting, he argued with the school to have the rule changed. A friendship developed between the two, and they married on 21 December 1904, later returned to St. Petersburg in 1907. Under Russian law, marriage was not allowed between two people of different religions. Since Tatyana was a Russian Orthodox and Ehrenfest was Jewish, they both decided to officially renounce their religions in order to remain married. They had two daughters and two sons; one daughter, Tatyana Ehrenfest, also became a mathematician. In 1912 they moved to

Leiden Leiden ( ; ; in English language, English and Archaism, archaic Dutch language, Dutch also Leyden) is a List of cities in the Netherlands by province, city and List of municipalities of the Netherlands, municipality in the Provinces of the Nethe ...

in the Netherlands, where Paul Ehrenfest was appointed to succeed

Hendrik Lorentz Hendrik Antoon Lorentz ( ; ; 18 July 1853 – 4 February 1928) was a Dutch theoretical physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for their discovery and theoretical explanation of the Zeeman effect. He derive ...

as professor at the

University of Leiden Leiden University (abbreviated as ''LEI''; ) is a public research university in Leiden, Netherlands. Established in 1575 by William, Prince of Orange as a Protestant institution, it holds the distinction of being the oldest university in the Neth ...

, and where the couple lived throughout their career.

Works in mathematics and physics

Initially, Afanasyeva-Ehrenfest collaborated closely with her husband, most famously on their classic 1911 review of the

Ludwig Boltzmann Ludwig Eduard Boltzmann ( ; ; 20 February 1844 – 5 September 1906) was an Austrian mathematician and Theoretical physics, theoretical physicist. His greatest achievements were the development of statistical mechanics and the statistical ex ...

. ''The Conceptual Foundations of the Statistical Approach in Mechanics,'' by Paul and Tatyana Ehrenfest was originally published in 1911 as an article for the German ''Encyklopädie der mathematischen Wissenschaften'' (''Encyclopedia of Mathematical Sciences''), and has since been translated and republished. Afanasyeva-Ehrenfest published many papers on various topics such as

randomness In common usage, randomness is the apparent or actual lack of definite pattern or predictability in information. A random sequence of events, symbols or steps often has no order and does not follow an intelligible pattern or combination. ...

and

entropy Entropy is a scientific concept, most commonly associated with states of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the micros ...

, and

teaching Teaching is the practice implemented by a ''teacher'' aimed at transmitting skills (knowledge, know-how, and interpersonal skills) to a learner, a student, or any other audience in the of an educational institution. Teaching is closely related ...

geometry Geometry (; ) is a branch of mathematics concerned with properties of space such as the distance, shape, size, and relative position of figures. Geometry is, along with arithmetic, one of the oldest branches of mathematics. A mathematician w ...

to children.

Contact with Einstein

Albert Einstein Albert Einstein (14 March 187918 April 1955) was a German-born theoretical physicist who is best known for developing the theory of relativity. Einstein also made important contributions to quantum mechanics. His mass–energy equivalence f ...

was a frequent guest in the 1920s to , as evidenced by the many signatures on the wall. Later Einstein departed for

Princeton University Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...

and Afanasyeva corresponded. The archives of Museum Boerhaave in Leiden has three letters to her from Einstein. Afanasyeva-Ehrenfest contacted Einstein for his advice on her manuscript on thermodynamics and inquired about a translator. She wanted to give thermodynamics a rigorous mathematical foundation which was lacking and describe pressure, temperature and entropy in changing systems. Einstein responded on 12 August 1947 that he applauded her approach but he also had some criticisms: :"Ich habe den Eindruck gewonnen, dass Sie ein bisschen von logischen Putzteufel besessen sind, und dass daran die Übersichtlichkeit des Buches leide." :(Translation: I have got the impression, that you are possessed somewhat by a logical polishing devil, and that the clarity of the book suffers.) Einstein did not suggest a translator and sent the manuscript back to Afanasyeva-Ehrenfest who paid herself for its publication in 1956 as ''Die Grundlagen der Thermodynamik'' with

Brill Publishers Brill Academic Publishers () is a Dutch international academic publisher of books, academic journals, and Bibliographic database, databases founded in 1683, making it one of the oldest publishing houses in the Netherlands. Founded in the South ...

in Leiden with some, but not all of Einstein's corrections.

Legacy

The Dutch Physics Council sponsors the ''Ehrenfest-Afanassjewa thesis award''.

References

Sources

* *

External links

Tatiana Ehrenfest-Afanaseva
CWP UCLA biography * Paul and Tatiana Ehrenfest:
The Conceptual Foundations of the Statistical Approach in Mechanics, translation Michael J. Moravesik, Dover publications New York 1990 (reprint of the edition of 1959), with a preface by T. Ehrenfest-Afanassjewa.
' {{DEFAULTSORT:Afanasyeva, Tatyana 1876 births 1964 deaths Scientists from Saint Petersburg People from Kievsky Uyezd 20th-century Russian mathematicians Mathematicians from the Russian Empire Probability theorists White Russian emigrants to Germany White Russian emigrants to the Netherlands Emigrants from the Russian Empire to the Netherlands Women scientists from the Russian Empire 20th-century Dutch women scientists 20th-century Russian women scientists 20th-century women mathematicians 20th-century Russian women