Дэвид Блэквелл: Американ математигі және статистикашысы

American mathematician and statistician

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David Harold Blackwell (April 24, 1919 – July 8, 2010) was an American statistician and mathematician who made significant contributions to game theory, probability theory, information theory, and statistics. He is one of the eponyms of the Rao–Blackwell theorem. He was the first African American inducted into the National Academy of Sciences, the first African American full professor (with tenure) at the University of California, Berkeley, and the seventh African American to receive a Ph. D. in mathematics. In 2012, President Barack Obama posthumously awarded Blackwell the National Medal of Science. Blackwell was also a pioneer in textbook writing. He wrote one of the first Bayesian statistics textbooks, his 1969 Basic Statistics. By the time he retired, he had published over 90 papers and books on dynamic programming, game theory, and mathematical statistics. He was the eldest of four children with two brothers, J. W. and Joseph, and one sister, Elizabeth. Growing up in an integrated community, Blackwell attended "mixed" schools, where he distinguished himself in mathematics. During elementary school, his teachers promoted him beyond his grade level on two occasions. It was in a high school geometry course, however, that his passion for mathematics began. An exceptional student, Blackwell graduated high school in 1935 at the age of sixteen. His doctoral advisor was Joseph L. Doob. At the time, Blackwell was the seventh African American to earn a Ph. D. in mathematics in the United States and the first at the University of Illinois at Urbana Champaign. His doctoral thesis was on Markov chains.

Blackwell completed one year of postdoctoral research as a fellow at the Institute for Advanced Study (IAS) at Princeton in 1941 after receiving a Rosenwald Fellowship, which was a fund to aid black scholars. because of his race. Having been highly recommended by his dissertation advisor Joseph L. Doob for a position at the University of California, Berkeley, he was interviewed by statistician Jerzy Neyman. Neyman supported his appointment, and Griffith C. Evans, the head of the mathematics department, at first agreed and even convinced university president Robert Sproul that it was the correct decision, only to subsequently balk, citing the concerns of his wife. It was customary for Evans and his wife to invite the members of the department over for dinner and "she was not going to have any darkie in her house." He was offered a post at Southern University at Baton Rouge, which he held in from 1942 to 1943, followed by a year as an Instructor at Clark College in Atlanta.

Blackwell joined the Mathematics Department at Howard University in 1944. When he joined, he was one of four faculty members and within three years he was appointed full professor and head of the department. The theorem provides a method for improving statistical estimates by potentially reducing their mean squared error. From 1948 to 1950, Blackwell spent his summers at RAND Corporation with Meyer Abraham Girshick and other mathematicians exploring the game theory of duels. In 1954, Girshick and Blackwell published Theory of Games and Statistical Decisions. Aside from von Neumann and Girshick, other Blackwell collaborators and mentors included Leonard J. Savage, Richard E. Bellman, and Nobel Laureate Kenneth J. Arrow.

Blackwell took a position at the University of California, Berkeley as a visiting professor in 1954, and was hired as a full professor in the newly created Department of Statistics in 1955. He became the Statistics department chair in 1957. Blackwell bridged topology and game theory via a game theoretic proof of Kuratowski's theorem in 1967. Blackwell only briefly extended his research beyond zero sum games to explore the sure thing principle as introduced by Jimmie Savage, primarily due the real world societal implications of the mathematical result, particularly for nuclear disarmament at the inception of the Cold War. Blackwell wrote one of the first Bayesian textbooks, his 1969 Basic Statistics. It inspired the 1995 textbook Statistics: A Bayesian Perspective by the biostatistician Donald Berry. He spent the rest of his career at UC Berkeley, retiring in 1988 three sons and five daughters: Ann, Julia, David, Ruth, Grover, Vera, Hugo, and Sara. David Blackwell died of complications from a stroke on July 8, 2010, at Alta Bates Summit Medical Center in Berkeley, California. He was 91 years old.

The Mathematical Association of America's MathFest, in coordination with the National Association of Mathematicians, features an annual MAA NAM David Blackwell Lecture. The Blackwell Tapia prize is named in honor of David Blackwell and Richard A. Tapia. The University of California, Berkeley named an undergraduate residence hall in his honor, named David Blackwell Hall. The residence hall opened in Fall 2018. An educational book about his life titled David Blackwell and the Deadliest Duel was published in 2019. Blackwell made the following statement about his values and work in an 1983 interview for a project called "Mathematical People":<blockquote>Basically, I'm not interested in doing research and I never have been I'm interested in understanding, which is quite a different thing. And often to understand something you have to work it out yourself because no one else has done it.