Beatrice Muriel Hill was born in Chester, England, on Jan. 27, 1941, and grew up in New Zealand, the middle of three daughters of Jean and Edward Hill. Her father was a clergyman turned politician who became mayor of New Plymouth in New Zealand.

“Beetle,” as her friends and family called her, had a healthy disrespect for authority, which would influence her attitudes toward both science and religion. As she grew up her two loves were music and mathematics.

At the University of Canterbury in Christchurch, New Zealand, she fell under the spell of physics, learning, as quoted in a biographical memoir by her father, “to question everything.” In 1961 she married a fellow physicist and classmate, Brian Tinsley. A year later she emerged with a master’s degree, but could not find work at Canterbury because her husband worked there.

When her husband was recruited to the Southwest Center for Advanced Studies in Dallas — now the University of Texas at Dallas — she followed, but found the situation stultifying. She once caused a minor scandal by refusing to host a faculty tea when it was her turn. In 1964 she enrolled as a graduate student at the University of Texas at Austin, the only woman in the program, commuting 400 miles every week.

It was while simulating the effects of the evolution of billions of stars on the overall appearance of galaxies that she crossed swords with Allan Sandage.

The fate of the universe was the big question in cosmology. Would the universe keep expanding forever? Or would the combined gravity of the galaxies eventually pull everything back together, like a handful of rocks tossed back to Earth?

Sandage and others sought to answer that question by looking at how the universe had been expanding in the deep past. He concluded that it was slowing down and would one day fall back together in a Big Crunch. That was about as momentous a prediction as any scientist could ever make.