Jacob Bekenstein, the Michael Polak Professor of Theoretical Physics emeritus at the Hebrew University of Jerusalem who revolutionized the study of black holes, died, unexpectedly, of a heart attack, Aug. 16, 2015. He was 68.

Bekenstein graduated from the Polytechnic Institute of Brooklyn (now the NYU Polytechnic School of Engineering) in 1969. In 1972, he earned a Ph.D. in physics from Princeton under the eminent John A. Wheeler, who popularized the term “black hole.” Bekenstein’s doctoral dissertation contained his groundbreaking work on black-hole entropy.

In 1974, Bekenstein joined the Ben-Gurion  University in Israel, becoming a full professor in 1978 and chair of the astrophysics department in 1983. In 1990, he became a professor at the Hebrew University of Jerusalem and head of the theoretical physics department three years later.

Bekenstein’s work on black holes, entropy, and thermodynamics initiated the field of black hole thermodynamics, which became the foundation for the science of quantum gravity. Among his many honors, he received the Wolf Prize in 2012 and the American Physical Society’s Einstein Prize in 2015, both of which are often precursors of the Nobel Prize.

He is survived by his wife, Bilha; three children; and six grandchildren.

Graduate memorials are prepared by the APGA.

Graduate Class of 1972