Lipman Bers facts for kids

Lipman Bers (born May 22, 1914 – died October 29, 1993) was an amazing Latvian-American mathematician. He was born in Riga, Latvia. Bers developed new ideas in math, like the theory of pseudoanalytic functions. He also studied complex shapes called Riemann surfaces and special groups of numbers called Kleinian groups. Beyond his math work, he was also a strong supporter of human rights.

Life Story of Lipman Bers

Early Life and Education

Lipman Bers was born in Riga, which was part of the Russian Empire at the time. As a young child, he lived in Saint Petersburg, Russia. Around 1919, his family moved back to Riga, which had become an independent country called Latvia.

In Riga, both of Bers' parents were principals of Jewish schools that he attended. For a short time, he lived in Berlin, Germany, while his mother studied there. After high school, Bers studied at the University of Zurich for a year. He then returned to Riga to continue his studies at the University of Riga.

Political Involvement and Escape

While at the University of Riga, Bers became very active in socialist politics. He gave speeches and worked for an underground newspaper. In 1934, a new leader named Kārlis Ulmanis took power in Latvia. Bers was targeted for arrest because of his political views. He had to flee the country, first to Estonia and then to Czechoslovakia.

Studies in Prague and Moving to the US

Bers earned his PhD in 1938 from the University of Prague. His main teacher there was Charles Loewner. In Prague, he lived with his aunt and married his wife, Mary, whom he had known since elementary school.

After the Munich Agreement, when Nazi Germany took over part of Czechoslovakia, Bers and Mary got a visa to go to France. They had a daughter in Paris. It was hard to get a visa to move to the U.S. from there. So, they escaped to the south of France just before Paris fell during World War II. They finally got an emergency U.S. visa in Marseilles. This was one of 10,000 special visas set aside for political refugees by Eleanor Roosevelt. The Bers family then joined Lipman's mother in New York City.

Career in Mathematics

During World War II, Bers taught math at Brown University. After the war, he became a professor at Syracuse University (1945–1951). He then moved to New York University (1951–1964) and later to Columbia University (1964–1982). At Columbia, he became a very important professor and even led the math department from 1972 to 1975.

Bers was also a leader in the math community. He was a Vice-President and later President of the American Mathematical Society. He also led important math committees for the U.S. government and the National Academy of Sciences.

Lipman Bers passed away on October 29, 1993, after dealing with Parkinson's disease and strokes.

Lipman Bers' Math Discoveries

Early Work and Fluid Dynamics

Bers' early research was about potential theory, which helps understand things like gravity or electricity. In Paris, he worked on Green's function and integral representations. When he first moved to the U.S., he even researched Yiddish math textbooks for a while.

At Brown University, he started working on fluid dynamics. This is the study of how liquids and gases move. He focused on how air flows around airplane wings. Around this time, he began working on pseudoanalytic functions with Abe Gelbart. He kept developing this theory through the 1940s and 1950s. He used it to study how fluids flow smoothly.

Bers also made a big discovery about minimal surfaces. These are shapes that have the smallest possible surface area for their boundaries, like soap films. He showed that certain "holes" or singularities in these surfaces could be "removed." He shared this important result at a big math conference in 1950.

Exploring Complex Shapes

Later, Bers started a new journey into different areas of math. He explored quasiconformal mappings, Teichmüller theory, and Kleinian groups. With another famous mathematician, Lars Ahlfors, he solved the "moduli problem." This problem was about finding a way to describe all possible shapes of certain complex surfaces called Riemann surfaces.

During this time, Bers also asked a famous question: "Can one hear the shape of a drum?" This question asks if you can figure out the exact shape of a drum just by listening to its sound. This question was later answered, but not by him directly.

In the late 1950s, Bers wrote several important summaries of his work. He covered topics like fluid flows, pseudoanalytic functions, and Riemann surface theory. In 1958, he gave another talk at a major math conference about his work on Riemann surfaces.

Advanced Theories and Conjectures

In the 1960s, Bers' work on Riemann surfaces led him to study the edges of these complex spaces. This led to new types of Kleinian groups. He also used a math tool called Eichler cohomology to study these groups.

He proved the Bers area inequality. This is a way to measure the area of certain hyperbolic surfaces. This work was important for later discoveries about 3D shapes. Bers also studied the continuous symmetries of hyperbolic 3-space.

Bers also helped define something called a Bers slice. In 1970, he made a guess, or conjecture, about where certain Kleinian groups could be found. This guess, known as the Bers density conjecture, was finally proven true by other mathematicians in 2010 and 2011. The Bers compactification of Teichmüller space also comes from this period.

Helping Future Mathematicians

Throughout his career, Lipman Bers was a mentor to about 50 students who were getting their PhDs. Some of his famous students include Enrico Arbarello, Irwin Kra, and Linda Keen. About a third of his students were women, which was a very high number for math at that time.

Bers felt that his own teacher hadn't paid enough attention to him. So, he made sure to meet regularly with his students. He cared about their personal lives as well as their math studies. He even had a friendly competition with Lars Ahlfors to see who could bring more of their former students to math gatherings!

Fighting for Human Rights

As a young child, Bers had been excited about the Russian Revolution. But by the late 1930s, he became disappointed with communism after seeing events like Stalin's purges. His son, Victor Bers, later said that Lipman's experiences in Europe made him want to fight for human rights. Bers himself said his interest came from the ideas of a leader named Julius Martov.

Bers started the Committee on Human Rights for the National Academy of Sciences. Starting in the 1970s, he worked hard to help Soviet mathematicians who were being treated unfairly to leave their country. These included people like Yuri Shikhanovich and the Chudnovsky brothers. In the U.S., he also spoke out against the Vietnam War and the build-up of nuclear weapons during the Cold War.

Awards and Special Recognitions

Lipman Bers received many honors for his work.

• In 1961, he was chosen as a Fellow of the American Academy of Arts and Sciences.
• In 1965, he became a Fellow of the American Association for the Advancement of Science.
• In 1964, he joined the National Academy of Sciences.
• He was also a member of the Finnish Academy of Sciences and the American Philosophical Society.
• In 1975, he won the Leroy P. Steele Prize from the American Mathematical Society for his clear writing about math.
• In 1986, the New York Academy of Sciences gave him their Human Rights Award.
• In the early 1980s, the Association for Women in Mathematics held a special event to honor Bers for helping so many women become mathematicians.