Throughout his long life, nuclear scientist Herbert Isbin reached the highest peaks of his profession.

Isbin earned a doctoral degree from the Massachusetts Institute of Technology. He was a professor of chemical engineering at the University of Minnesota for 33 years, eventually earning emeritus status. He was the director of the university’s gamma irradiation facility, and there’s a fellowship and archive at the U dedicated to him. He penned an internationally known textbook called “Introductory Nuclear Reactor Theory,” which is still used today. And he was appointed to the U.S. Atomic Energy Commission by President Dwight Eisenhower.

Isbin was, by all accounts, one heck of a square dancer, too. He and his wife, Katherine, were known for hosting elaborate square dances in the basement of their St. Louis Park home, complete with costumes and a caller.

He was “the perfect balance of humility and debonair,” said Rabbi Avi Olitzky of Beth El Synagogue in St. Louis Park, where the family attends.

Isbin, 98, died on May 12 of congestive heart failure.

“He had a remarkable life, it was a good run,” said his son, Ira Isbin.

Born in Seattle, Isbin received bachelor’s and master’s degrees from the University of Washington. While studying at MIT in the late 1940s, he received a fortuitous phone call from his long-standing pen pal, Katherine. She and her mother were stranded in New York City, and Isbin was in Boston preparing to drive to Washington state for his first job. Could he give them a ride to Minneapolis?

After arriving in town, a stroll around the Lake of the Isles in Minneapolis led to a wedding proposal. The two were married for 64 years.

“This was the woman he wanted to be with, they were totally in love,” Ira Isbin said.

Herbert and Katherine had four children — Ira, Sharon, Neil and Rena — all fiercely independent and high achievers. Katherine, who died in 2012, received a law degree from the U and was admitted to the bar in 1945, quite a feat for a woman in those days.

Daughter Sharon Isbin’s first interest was science, so her father brought home a microscope to help her dissect insects. He told her she couldn’t shoot off model rockets in the backyard until she practiced guitar for an hour. Her father’s strict but gentle coaching paid off — Sharon Isbin is a widely heralded, Grammy Award-winning classical guitarist.

“My father was always in the front row, cheering me on,” she said of her formative years.

Isbin long refused to divulge details about his stint during World War II with the Office of Strategic Services, a predecessor of the Central Intelligence Agency — despite gentle ribbing from friends and family.

“Herb’s type of humor would leave him to laugh even before finishing a joke, and his laughter alone would have you in stitches,” Olitzky said.

When son Neil Isbin became ill with AIDS in the mid-1990s, his parents stayed by his side in New Mexico for a year. After Neil died, they established the Neil Isbin Scholarship Fund, which awards scholarships to Albuquerque high school students interested in human rights work.

Daughter Rena Isbin described her father as “a highly evolved soul [who] set the bar high and gave us all something to aspire to by simply living his truth. Brilliant, kind, thoughtful, humble, receptive and giving. A true gift to know and love.”

Funeral services have been held. A celebration of Isbin’s life will be held at a later date.