During those long car and airplane trips to visit family, spare a thought for Irving Liberman, a scientist who helped make GPS a reliable, precise resource. He died on Nov. 6 at his home in the Squirrel Hill section of Pittsburgh. He was 86.

A lifelong tinkerer, Mr. Liberman was always fascinated by how things worked. At a young age, he would take things apart and put them back together, sometimes with parts left over, yet they still worked. Before he would use any gadget, he had to know how it worked.

The owner of eight patents and author of more than 50 publications, Mr. Liberman, who had earned master’s and doctoral degrees in electrical engineering, was recruited by Westinghouse Research & Development. In 1995, he was the project manager for a cohort that developed the miniature atomic clock, which was accurate within a millionth of a second per day and would come to be used for many disciplines, especially GPS technology, and also smart bombs, cellular communication systems and even the ankle bracelets worn by prisoners.