Stephen Hawking is one of our greatest living geniuses—his insights into the nature of black holes, space and time have truly revolutionized physics. But his breakthroughs did not spring from his mind fully formed—they required hard work and sacrifice, from both the physicist and from his first wife, Jane Wilde. In the new biographical film The Theory of Everything we see the toll Hawking’s work and his illness took on their marriage and on both individuals.

The film portrays physics as Hawking’s first and deepest love, his driving reason for living. As he becomes increasingly disabled by amyotrophic lateral sclerosis (ALS), Hawking’s brain seems to drag his body unwillingly along for the ride. The person who enables all this, who carries and feeds and dresses him, who manages his schedule of presentations and meetings and somehow transports him around the cobblestones of Cambridge, England, is Wilde. “That support system and the fact that she’s agreed to stay with him when he’s diagnosed [with ALS], I’m sure that enabled the work to happen,” says James Marsh, the film’s director. “Stephen himself said sometimes he was so free of practicalities, his mind was able to wander where it did to the far reaches of the universe.”

And certainly Hawking’s own health is strained by his work and the travel and exertion his career required. Although perhaps his lively mind and his passion for physics also played some role in helping the scientist live to 72 with ALS, long past the two years his doctors originally estimated he would survive. “There’s a balance between Stephen’s career and his illness,” Marsh says. “The more Stephen becomes physically incapacitated, it seems the more his ideas grow.”

Actor Eddie Redmayne beautifully illustrates the progression of Hawking’s disease over a time span of roughly 50 years, from before his diagnosis through every stage of his illness to today. Initially skeptical of the film, the real-life Hawking seems to have been won over by the portrayal. “After the film was shot and we were finishing it up we had to show it to him,” Marsh says. “That was a very tense experience as a filmmaker. His reaction seemed to be quite emotional as best as I could discern and he said he felt it was broadly true. Subsequently to that he e-mailed the production to say that at a certain point he felt he was watching himself on screen.”

Wilde was more involved in the production of the film, which was based on her 2007 memoir Traveling to Infinity: My Life with Stephen. “She took me to the second house where they lived when Stephen was a professor,” Marsh recalls. “She explained what was a very crucial moment in the film, when Stephen had an idea and he was tangled in his pajamas. The breakthrough was sourced in something that happened in the moment. We reproduced that in the film.” Actress Felicity Jones touchingly portrays her love for her husband and the tenderness with which she cares for him, including rescuing his from his pajamas when needed.

Over the years, though, Hawking and Wilde’s bond seems to fray under all the pressure. As Hawking achieves greater fame and acclaim for his work in physics, and his illness progressively takes over his body, the film shows the strain Wilde feels in caring for him, and her growing attachment to an understanding church choirmaster. Ultimately, Hawking and Wilde divorce and both marry other people. “There’s a love triangle in the film where everyone in that triangle has good intentions,” Marsh says. “I think both Jane and Stephen accepted the portrait we’ve created in the film that feels very truthful to them.”

Although Hawking and Wilde’s circumstances were certainly unique, some of their problems are actually common to other relationships involving scientific visionaries. Albert Einstein, for example, had a very troubled marriage to his first wife, Mileva Marić, another physicist. Marić complained of Einstein’s all-consuming devotion to science and of always taking “second place” to his work. It turns out even geniuses can be fools in love.