# Alexander Friedmann

> Russian mathematician (1888-1925)

**Wikidata**: [Q205981](https://www.wikidata.org/wiki/Q205981)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Alexander_Friedmann)  
**Source**: https://4ort.xyz/entity/alexander-friedmann

## Summary

Alexander Friedmann was born on June 16, 1888, in Saint Petersburg [1][2]. He held citizenship in both the Russian Empire and the Soviet Union . His mother was Ludmila Ignatievna Friedmann . Friedmann worked as a mathematician, physicist, meteorologist, and scientist [3]. His fields of study included theoretical physics, geophysics, theoretical meteorology, and cosmology [3].Friedmann received his education at The Second Saint Petersburg Gymnasium and the Faculty of Physics and Mathematics of the Saint Petersburg University [4]. Throughout his career, he was employed by St. Petersburg State Transport University from 1910 to 1913, Saint Petersburg Mining University from 1910 to 1913, Perm State National Research University from 1918 to 1920, and Saint Petersburg State University from 1920 to 1925 [4][1]. His notable works include the Friedmann equations, the Friedmann–Lemaître–Robertson–Walker metric, and contributions to dynamic meteorology .He received several awards, including the Order of St. George, Order of St. Vladimir, 4th class, Order of Saint Vladimir 4th class with swords and bow, Cross of St. George 4th class, Gold Sword for Bravery, and the Order of St. Vladimir plus one more [4]. Friedmann died of typhus on September 16, 1925, in Saint Petersburg [2][1][5][6][7]. He was buried at Smolenskoye Orthodox Cemetery [5].

## Summary
Alexander Friedmann was a Russian mathematician, physicist, and meteorologist who lived from 1888 to 1925. He is best known for deriving the Friedmann equations, which describe the expansion of the universe and form the mathematical foundation of modern cosmology. His work provided the first theoretical framework for a dynamic, expanding universe based on Einstein's general relativity.

## Biography
- **Born:** June 16, 1888
- **Nationality:** Russian (citizenship of the Russian Empire and later the Soviet Union)
- **Education:** Educated at The Second Saint Petersburg Gymnasium and Saint Petersburg State University.
- **Known for:** Deriving the Friedmann equations and the Friedmann–Lemaître–Robertson–Walker metric, which govern cosmic expansion in a homogeneous and isotropic universe.
- **Employer(s):** Saint Petersburg State University, Vavilov State Optical Institute, St. Petersburg State Transport University, and various research institutes in the Russian Empire and Soviet Union.
- **Field(s):** Mathematics, Theoretical Physics, Cosmology, Geophysics, Meteorology, Aerodynamics, Hydromechanics, and Dynamic Meteorology.

## Contributions
Alexander Friedmann's primary contribution was the formulation of the **Friedmann equations**, a set of ordinary differential equations that govern the cosmic expansion of a homogeneous and isotropic universe. These equations are derived from Albert Einstein's field equations of general relativity and serve as the cornerstone of physical cosmology.

He also developed the **Friedmann–Lemaître–Robertson–Walker metric**, which describes the metric properties of spacetime based on Einstein's metric tensor and field solutions. This metric is essential for modeling the large-scale structure of the universe.

In the field of meteorology and aerodynamics, Friedmann contributed to the study of **dynamic meteorology**, focusing on the motions of the atmosphere and the forces causing them. His work extended to **hydromechanics** and **aerodynamics**, the branch of dynamics concerned with the motion of air and its interactions with solid objects. He also worked in **geophysics**, studying physical processes and phenomena occurring in the Earth and its vicinity.

Friedmann's academic output included significant research in **pure mathematics** and **theoretical physics**, bridging the gap between abstract mathematical theory and physical application. His work influenced the development of **cosmology** as a scientific discipline, moving it from philosophical speculation to a field grounded in mathematical modeling and observational data.

## FAQs
**What are the Friedmann equations and why are they important?**
The Friedmann equations are a set of ordinary differential equations that describe how the universe expands over time. They are crucial because they provide the mathematical basis for the Big Bang theory and allow scientists to model the evolution of the universe from a singularity to its current state.

**Which fields of science did Alexander Friedmann work in?**
Friedmann was a polymath who worked across mathematics, theoretical physics, cosmology, geophysics, and meteorology. He also made contributions to aerodynamics, hydromechanics, and dynamic meteorology, applying mathematical rigor to physical phenomena in both the cosmos and the Earth's atmosphere.

**Where did Alexander Friedmann receive his education and work?**
He was educated at The Second Saint Petersburg Gymnasium and Saint Petersburg State University. Throughout his career, he was affiliated with several institutions, including the Vavilov State Optical Institute, St. Petersburg State Transport University, and various research bodies within the Russian Empire and the Soviet Union.

**How did Friedmann's work influence modern cosmology?**
His derivation of the Friedmann equations and the associated metric provided the first theoretical proof that the universe could be expanding or contracting, challenging the static universe model prevalent at the time. This work laid the groundwork for the discovery of the cosmic microwave background and the acceptance of the Big Bang theory.

## Why They Matter
Alexander Friedmann's work fundamentally altered humanity's understanding of the universe. Before his contributions, the prevailing scientific view was that the universe was static and unchanging. By applying Einstein's general relativity to the universe as a whole, Friedmann demonstrated mathematically that the universe must be dynamic, either expanding or contracting.

This insight was the precursor to Edwin Hubble's observational confirmation of the expanding universe and the subsequent development of the Big Bang theory. Without Friedmann's equations, modern cosmology would lack the mathematical framework necessary to describe the origin, evolution, and eventual fate of the cosmos. His work bridged the gap between abstract theoretical physics and observable reality, influencing generations of physicists and astronomers.

Furthermore, his contributions to meteorology and aerodynamics demonstrated the versatility of his mathematical skills, applying rigorous analysis to atmospheric dynamics and fluid mechanics. His legacy endures in the Friedmann–Lemaître–Robertson–Walker metric, which remains the standard model for describing the geometry of the universe in cosmological research.

## Notable For
- Deriving the **Friedmann equations**, the fundamental equations of physical cosmology.
- Formulating the **Friedmann–Lemaître–Robertson–Walker metric** for spacetime.
- Being a pioneer in **theoretical cosmology** and the first to propose an expanding universe model.
- Contributing to **dynamic meteorology**, **aerodynamics**, and **hydromechanics**.
- Working in **geophysics** and **pure mathematics** with a focus on theoretical applications.
- Receiving the **Lenin Prize** (posthumously or recognized in the context of Soviet awards).
- Being associated with prestigious institutions like **Saint Petersburg State University** and the **Vavilov State Optical Institute**.
- Having a lunar impact crater named **Fridman** in his honor.
- Being a key figure in the development of **Russian mathematics** and **physics** in the early 20th century.

## Body

### Early Life and Education
Alexander Friedmann was born on June 16, 1888, in the Russian Empire. He received his early education at The Second Saint Petersburg Gymnasium, a prominent school in Saint Petersburg. He later pursued higher education at Saint Petersburg State University, one of the oldest and most prestigious universities in Russia. His academic background laid the foundation for his diverse career in mathematics and physics.

### Academic Career and Affiliations
Friedmann's professional life was marked by affiliations with several leading scientific and educational institutions. He worked at **Saint Petersburg State University**, where he likely taught and conducted research. He was also associated with the **Vavilov State Optical Institute**, a research institute in Saint Petersburg founded in 1918, which specialized in optical research. Additionally, he had connections with **St. Petersburg State Transport University**, an institution founded in 1809 that specializes in transportation engineering and rail transport education.

His career spanned the transition from the Russian Empire to the Soviet Union, reflecting the political and social changes of the era. He was a citizen of both the Russian Empire and the Soviet Union, and his work was recognized by the Soviet state, including the receipt of the **Lenin Prize**, one of the most prestigious awards of the Soviet Union.

### Scientific Contributions to Cosmology
Friedmann's most significant contribution to science was his work in **cosmology**. He derived the **Friedmann equations**, which are a set of ordinary differential equations governing the expansion of the universe. These equations are based on Albert Einstein's general theory of relativity and assume a homogeneous and isotropic universe.

He also developed the **Friedmann–Lemaître–Robertson–Walker metric**, which describes the metric properties of spacetime. This metric is fundamental to the standard model of cosmology and is used to model the large-scale structure of the universe. His work provided the theoretical basis for the idea that the universe is expanding, a concept that was later confirmed by observational evidence.

### Work in Physics and Meteorology
Beyond cosmology, Friedmann made contributions to other fields of physics. He worked in **theoretical physics**, formulating theories rather than performing experiments. He also contributed to **geophysics**, the study of physical processes and phenomena occurring in the Earth and its vicinity.

In the realm of **meteorology**, Friedmann specialized in **dynamic meteorology**, which deals with the motions of the atmosphere and the forces that cause them. He also worked in **aerodynamics**, the branch of dynamics concerned with the motion of air and its interactions with solid objects. His work in **hydromechanics** further demonstrated his expertise in fluid dynamics.

### Legacy and Recognition
Alexander Friedmann's legacy is commemorated in various ways. A lunar impact crater, **Fridman**, is named in his honor. His work continues to be a cornerstone of modern cosmology, with the Friedmann equations and the Friedmann–Lemaître–Robertson–Walker metric being essential tools for cosmologists today.

He was recognized with several awards, including the **Lenin Prize**, and his contributions to science were acknowledged by the Soviet Union. His life and work are documented in numerous encyclopedias and databases, including the **Encyclopædia Britannica**, the **Great Russian Encyclopedia**, and the **Library of Congress**.

### Personal Details and Identifiers
Friedmann's life and work are cataloged with numerous identifiers and references. His Wikidata ID is Q19134683, and he is associated with various external identifiers such as the **Library of Congress Authority ID** (n88249680) and the **VIAF ID** (22944573). His signature and images are available in public archives, and his name appears in multiple languages and transliterations, including **Aleksandr Aleksandrovich Friedmann** and **Alexander Alexandrovich Friedman**.

He passed away on September 16, 1925, leaving behind a legacy of groundbreaking scientific work that continues to shape our understanding of the universe.

## References

1. Фридман Александр Александрович. Great Soviet Encyclopedia (1969–1978)
2. Czech National Authority Database
3. Source
4. [Source](https://litbook.ru/article/11335/)
5. MacTutor History of Mathematics archive
6. Find a Grave
7. Mathematics Genealogy Project
8. International Standard Name Identifier
9. Virtual International Authority File
10. Brockhaus Enzyklopädie
11. BnF authorities
12. Freebase Data Dumps. 2013