Died in Leiden, Netherlands

Tatyana Afanasyeva-Ehrenfest died on September 29, 1964, in Leiden, the Netherlands, the city where she had lived and worked for much of her adult life following her marriage to physicist Paul Ehrenfest in 1904.

By the time of her death, she had built a substantial legacy as both a mathematician and physicist and as an influential figure in mathematics education in the Netherlands. She had co-authored, with her husband, the seminal 1911 Encyklopädie der mathematischen Wissenschaften article on the conceptual foundations of statistical mechanics, a work still cited by historians and physicists studying the Ehrenfest urn model and the foundations of thermodynamics.

After Paul Ehrenfest's death in 1933, she continued her own scholarly and pedagogical work, particularly in the reform of geometry teaching in Dutch schools, publishing influential textbooks and articles on didactics of mathematics. Her death in 1964 marked the end of a career that spanned six decades and two countries, leaving behind a body of work that influenced statistical physics, mathematics education, and the study of symmetry and geometric intuition. She is remembered as a bridge figure connecting rigorous theoretical physics with practical pedagogy, and as one of the notable women scientists of her era who overcame significant institutional barriers to contribute lasting scholarship.