Celebrating the Extraordinary Journey of C.R. Rao - Pioneer in Statistics
On August 23rd morning, the statistics community got to know about the passing of a towering figure in the world of statistics and mathematics, Calyampudi Radhakrishna Rao. Born on September 10th, 1920, in the tranquil town of Huvinahadagali (presently in Karnataka), Rao's exceptional journey in the field of statistics has left an indelible mark on the realms of knowledge.
From his early days, Rao's affinity for mathematics was nurtured by the stories of luminaries such as Srinivasa Ramanujan and Nobel laureate C.V. Raman—figures who eventually became his inspirations and role models. This early fascination laid the foundation for a remarkable academic journey.
Rao's educational path commenced at Mrs AVN College, where he embarked on a two-year intermediate course. His brilliance shone brightly as he not only pursued his course but also garnered the esteemed Chandrasekara Iyer scholarship, instituted by his idol C.V. Raman in honor of his father. This scholarship became a symbol of Rao's promising future, gracing his journey for two consecutive years.
In 1940, Rao attained his Master's degree in Mathematics from Andhra University, a pivotal step in his academic pursuit. The year 1941 marked his entry into the Indian Statistical Institute (ISI) as a statistical trainee, solidifying his commitment to the field. Furthering his education, he enrolled in Calcutta University's newly established master's program, emerging in 1943 with a Master's degree in Statistics, adorned with the highest rank and the prestigious gold medal.
Rao's contributions to ISI and the field of statistics were transformative. Joining as a regular employee in 1943, he embarked on a research journey that redefined statistical science. His collaboration with the renowned statistician P.C. Mahalanobis further enriched his impact and presence in the community.
A landmark year was 1945, marked by Rao's breakthrough paper that would reverberate throughout the world of statistics. The generation of terms like CR Bound, Rao-Blackwellization, Fisher Rao Metric, and Rao Distance through this paper signified a profound paradigm shift in statistical research. This paper introduced differential geometrical modeling ideas to the discipline, leaving an enduring legacy.
1946 witnessed Rao's expedition to the University of Cambridge, England, as part of an anthropology project under Mahalanobis. During his time there, from 1946 to 1948, he immersed himself in classification problems, culminating in the award of his doctorate in 1948 under the guidance of Prof. R.A. Fisher, the esteemed father of statistics. In 1965, he was once again honored by Cambridge University with an Sc.D.
Upon returning to India in 1948, Rao reunited with ISI, contributing profoundly to Indian statistical science. His marriage to Bhargavi Ji in the same year marked a personal milestone, complementing his stellar professional journey. Assuming the mantle of a professor in 1949, he eventually ascended to the Directorship of the Research and Training School at ISI. After P.C. Mahalanobis's demise, Rao assumed the role of Director and Secretary of ISI, guiding it into a new era. In 1976, he gracefully transitioned from directorship to the Jawaharlal Nehru Professorship at the Institute.
In 1978 he took temporary appointment at the University of Pittsburgh. This initial step marked the beginning of a remarkable chapter in his career, as he decided to make the United States his new academic home. The temporary appointment later evolved into a permanent position as a University Professor, solidifying his presence within the academic community.
Building on his dedication to statistical science, Rao's impact continued to expand. In 1988, he further elevated his academic pursuits by joining Pennsylvania State University as the Eberly Professor of Statistics, cementing his role as a visionary figure reshaping the landscape of statistical thought and education.
Rao's accolades and recognitions were abundant, reflecting his global influence. The Padma Vibhushan conferred upon him by the Government of India in 2001 stood as a testament to his exceptional contributions. The Wilks Medal from the American Statistical Association (1979) and the U.S. National Medal of Science (2002) underscored his profound impact on statistical science. Notably, his outstanding achievements were further recognized with the esteemed 2023 International Prize in Statistics, often referred to as the "Nobel Prize of Statistics."
Rao's intellectual prowess extended beyond accolades. With 14 books and over 410 research papers to his name, his work found applications even in quantum physics. The concept of Rao-Blackwellization revolutionized fields like adaptive sampling, particle filtering in high-dimensional state spaces, dynamic Bayesian networks, and more. These advancements had strategic implications in signal detection, non-friendly plane tracking, and shape-based object recognition.
Beyond his scholarly endeavors, Rao was an avid photographer, capturing moments of his cherished family. His affinity for computer programming languages mirrored his insatiable curiosity.
As a tribute to his enduring legacy, I recommend Rao's book 'Statistics and Truth - Putting Chance to Work,' first published in 1987, to readers of all walks. This timeless work unravels the enigma of statistics, demystifying concepts like artificial intelligence, meta-analysis, and even extrasensory perception (ESP).
Calyampudi Radhakrishna Rao's passing leaves an intellectual chasm, but his contributions will forever illuminate the path of statistical exploration and mathematical discovery.
Author: Harshvardhan Singh Garhwal (Indian Statistical Service 2021 Batch). Views are personal.
