Francis Sears in the context of Ultrasonic grating

Mark Waldo Zemansky (May 5, 1900 – December 29, 1981) was an American physicist. He was a professor of physics at the City College of New York for decades and is best known for co-authoring University Physics, an introductory physics textbook, with Francis Sears. The book, first published in 1949, is often referred to as "Sears and Zemansky", although Hugh Young became a coauthor in 1973.

University Physics, informally known as Sears & Zemansky, is a two-volume physics textbook written by Hugh Young and Roger Freedman. The first edition of University Physics was published by Mark Zemansky and Francis Sears in 1949. Hugh Young became a coauthor with Sears and Zemansky in 1973. Now in its 15th edition, University Physics is among the most widely used introductory textbooks in the world.

Hugh David Young (November 3, 1930 – August 20, 2013) was an American physicist who taught physics for 52 years at Carnegie Mellon University. Young is best known for co-authoring the later editions of University Physics, a highly regarded introductory physics textbook, with Francis Sears and Mark Zemansky (this book — first published in 1949 — is often referred to as "Sears and Zemansky", although Hugh Young became a coauthor in 1973).

Young was born on November 3, 1930, in Ames, Iowa, and was raised in Mondamin and Osage, Iowa. He came to Carnegie Mellon as an undergraduate physics major in 1948, and, by 1959, had earned a Bachelor of Science, Master of Science, and PhD in Physics from the university. He later earned a Bachelor of Fine Arts in music in 1972, concentrating in organ performance.