Sofya Kovalevskaya 

Part 2 - Berlin and Beyond

Berlin

After an initial visit with Karl Weierstrass August where he agreed to teach Sofya privately, the couple made the move to Berlin arriving October of 1870.

Göttingen University - Triple Dissertation

Without ever being officially accepted as a student, Sofya earned a doctorate in mathematics entirely on the strength of her original contributions to the field
— A Russian Childhood

Weierstrass did not fully understand why Sofia wanted an official degree, as he believed she was simply pursuing intellectual satisfaction. He did not realize the importance of official recognition of her scientific competence, which would have made it easier for her to secure employment in the male-dominated field of mathematics. Because women could not enroll as regular students at the University of Berlin, eventually Weierstrass campaigned his contemporaries at Göttingen University to accept her dissertations in absentia. Weierstrass specifically chose Gottingen for its liberal reputation, because Sofia's great grandfather had studied there and because the university had a long history of subtly supporting women in science. He wanted to ensure that her dissertations were strong enough to stand on their own, without the need for an oral defense that would require strong German language skills. He also feared that Sofia might be nervous when questioned by senior scholars.

Ultimately, Sofia's academic achievements and contributions to mathematics spoke for themselves, and she earned her doctor of philosophy in mathematics summa cum laude supported by Weierstrass, DuBoi-Reymond, Lazarus Fuchs and others in July 1874.

Julia Lermontova received her doctorate in chemistry from Göttingen University in the same year.

Return to Russia

Even with a doctoral degree Sofya was unable to find work in her home country. The stigma against learned women was too pervasive across society at the time, but she did return as a sort of celebrity, someone to be stared at and discussed, but not taken seriously. Frustrated, she packed away her mathematics work and let it gather dust for the next six years going so far as ignoring the letters from Weierstrass who by this time regarded her as a daughter, appalled by her wasting her gifts.

During this period in Russia, Sofya and Vladimir attempted to live as a more traditional husband and wife. Sofya along with Vladimir made their way though the extensive literary and intellectual circles in St. Petersburg. The couple was in need of financial support, Vladimir was unsuccessful finding a university professorship and the best job Sofya could find was teaching arithmetic to elementary girls. Using the inheritance that came to Sofya from her father’s death, Vladimir entered into the business of buying and selling houses. Unfortunately his plans vastly exceeded his capital quickly leading to mounting debts and angry creditors.

In 1878 she helped organize the “Higher Courses for Women” to help establish a women’s university within Russia. Vladimir helped with administration and fundraising for the school along with donating some of his publishing catalog to the school. But, after offering her services to teach without a salary, she was passed over as a member of the faculty. It was a blow to her ego.

Either due to the responsibility she felt towards her parents or an obligation to honor Vladimir, the couple ended up having their first child in October named Sofya Vladimirovna, nicknamed Fufa.

Meanwhile, Vladimir’s business opportunities were drastically worsening and Sofya didn’t handle the situation well. In a notebook she satirized them both, her husband for his comments on the incapacity of women to do creative work and herself as the erudite wife.

In January 1880, the Sixth Congress of Natural Scientist was held in St. Petersburg. The mathematician P.L. Chebyshev urged Sofya to present a paper on some of her work. Reluctantly, she returned to her unpublished dissertation on Abelian integrals. In a single night she translates the paper into Russian and the following morning read it to the audience with huge success. Despite six years elapsing, no other work had been done in this field. In one day she reestablished herself as a world class mathematician. In attendance was Gosta Mittag-Leffler, a former student of Weierstrass and a professor at the University of Helsingfors. Weierstrass had sent him to the congress with instructions to bring Sofya back into the fold of mathematics.

Paris

you write that no woman has created anything important, but it is just because of this that it is essential for me, while I still have energy and tolerable circumstances, to position myself so that I may show whether I can achieve anything or whether I lack brains.
— Sofya's letter to Vladimir after the separation
My work had something of an impact in the mathematical world, I had viewed it from a different, entirely new standpoint.
— Sofya on the problem of light refraction

Stockholm

Why, this is the first handsome mathematical lady I have ever seen!
— J.J. Sylvester, Professor of Mathematics, New College Oxford

The mathematics underlying Kovalevskaya's work on the motion of Saturn's rings involves a number of different concepts and techniques. Here are some of the key ideas:

  1. Rotating fluids: The rings of Saturn can be thought of as a system of small particles orbiting around the planet. However, because the rings are not a solid object, they behave more like a fluid. Kovalevskaya's analysis therefore focused on the motion of small particles in a rotating fluid, which she believed could provide insights into the behavior of the rings.

  2. Partial differential equations: To study the motion of the particles in the rotating fluid, Kovalevskaya used partial differential equations, which describe how the fluid velocity and pressure vary with time and position. These equations are notoriously difficult to solve, but Kovalevskaya was able to make progress using a technique called Fourier analysis.

  3. Fourier analysis: Fourier analysis involves breaking down complex functions into simpler components, called Fourier series, which are based on trigonometric functions. This technique can be used to decompose the complex motion of the particles in the rotating fluid into simpler components, which can then be analyzed more easily.

  4. Kovalevskaya's constant: One of the key contributions of Kovalevskaya's work was the introduction of a new concept, now known as Kovalevskaya's constant. This constant describes the maximum density of particles that can be supported in a rotating fluid without collapsing into a single mass. By calculating this constant for the rings of Saturn, Kovalevskaya was able to determine under what conditions the rings could be stable.

  5. Mathematical modeling: Finally, Kovalevskaya's work is a classic example of the use of mathematical modeling in science. By using mathematics to describe the behavior of a complex physical system, she was able to make predictions about the behavior of Saturn's rings that could be tested experimentally. Her work helped to establish the field of celestial mechanics as a legitimate area of research, and it demonstrated the power of mathematics to explain and predict phenomena in the natural world.

Sofya Kovalevskaya's work on the motion of Saturn's rings was based on the principles of fluid dynamics, partial differential equations, and Fourier analysis.

To begin with, Kovalevskaya assumed that the motion of small particles in a rotating fluid could be used as a model for the rings of Saturn. She then developed a set of partial differential equations to describe the motion of these particles, taking into account the forces of gravity, centrifugal force, and the pressure of the fluid.

Partial differential equations are a type of mathematical equation that describe how a quantity changes over time and space, taking into account multiple factors. They are used in many areas of science and engineering to model complex phenomena, such as fluid flow, heat transfer, and electromagnetic waves.

Once Kovalevskaya had formulated the equations for the motion of the particles, she needed to solve them to obtain a mathematical description of the behavior of the fluid. This is where Fourier analysis came in.

Fourier analysis is a mathematical technique that involves breaking down a complex motion into simpler components. Specifically, it involves expressing a function as a sum of sinusoidal functions, which describe the way in which the function varies with time and space.

Kovalevskaya used Fourier analysis to express the motion of the particles in the fluid as a sum of sinusoidal functions, which allowed her to separate out the different components of the motion. By doing this, she was able to simplify the equations for the motion of the particles and obtain a mathematical expression for the density of particles in the fluid.

Kovalevskaya then introduced the concept of Kovalevskaya's constant, which describes the maximum density of particles that can be supported in a rotating fluid without collapsing into a single mass. This constant was based on her mathematical analysis of the fluid dynamics of the particles, and it provided a critical threshold for determining the stability of Saturn's rings.

Kovalevskaya's analysis showed that if the density of particles in Saturn's rings was less than the critical value given by Kovalevskaya's constant, then the rings could be stable over long periods of time. This was a major breakthrough in the study of celestial mechanics, as it helped to explain why the rings of Saturn had not collapsed into a single mass over the course of millions of years.

Overall, Sofya Kovalevskaya's work on the motion of Saturn's rings was a remarkable achievement, as it involved the use of advanced mathematical techniques to solve a complex problem in celestial mechanics. Her ideas and methods continue to influence the study of fluid dynamics, partial differential equations, and other areas of mathematics today.

deeper dive into the math

Vera Sergeevna Goncharova

Vera was the original model for Sofya’s Nihilist Girl…find out more about her. She was one of the first group of four women who were permitted to study at the Faculty of Medicine in Paris.