As linear as Project Hail Mary‘s sci-fi story may seem, it secretly unfolds a darker tale of time dilation that makes it as bittersweet as Christopher Nolan’s Interstellar. While the movie’s overarching message about sacrifice, friendship, and having faith remains positive, the truth about its hidden time dilation science adds a darker layer of melancholy to its underlying story.
When it comes to portraying time dilation, Christopher Nolan’s Interstellar does not shy away from making it a crucial part of its narrative. In fact, some of the twistier and harder sci-fi elements in the movie are driven by its complex portrayal of the relativity of time.
Even the most hard-hitting and emotional scene in the film, in which Cooper sees video recordings of his family after returning from Miller’s planet, uses time dilation as a plot device to show how much relative time the protagonist has lost during his space mission. Project Hail Mary‘s time dilation aspects are never portrayed explicitly in the movie but they, too, shape the emotional weight of the film’s ending.
The Time Dilation In Project Hail Mary Explained
The foundation of time dilation in Project Hail Mary rests on the Lorentz transformation. Perhaps the easiest way to understand it is by recalling all the visual representations of speedsters (like Quicksilver in X-Men: Days of Future Past) on the screen. The faster they run and the closer they get to the speed of light, the slower their relative time becomes, allowing them to experience a relatively slower reality than others.
Similarly, even in Project Hail Mary, Ryland Grace experiences a slower passage of time compared to the people on Earth during his journey towards Tau Ceti because his spacecraft, Hail Mary, travels at more than 90% of the speed of light. Owing to this difference in relative time, it only takes him about four years to reach Tau Ceti but close to 12 to 14 years pass on Earth during his journey.
This explains why, in Project Hail Mary‘s ending moments, Grace barely seems to have aged, but Eva seems significantly older. The original Andy Weir book’s final arc also reveals that while Grace is 54 years old, 71 years have passed on Earth since his birth.
Andy Weir’s original Project Hail Mary book includes considerably more math and scientific explanation about Grace’s trip and its time dilation implications.
In both the movie and the book, this relativity even becomes a secret driver of a crucial story beat. Rocky’s species, the Eridians, are ignorant of relativity. Owing to this, they end up overestimating the amount of fuel they would require for their trip to Tau Ceti. With the additional fuel, Rocky is later able to help Grace return home while only slightly delaying his own return to his own planet.
However, beyond this optimistic development, the time dilation storyline also brings a tragic twist to the movie.
Project Hail Mary’s Time Dilation Mechanics Is Different From Interstellar’s, But It Has A Similar Bittersweet Ending
Unlike Project Hail Mary, Interstellar‘s time dilation has more to do with gravity rather than velocity. The primary source of time dilation in the Christopher Nolan movie is caused by the intense gravitational field of the black hole Gargantua, where extreme gravity warps spacetime and slows time for those closer to the source.
However, despite the difference in the mechanics of time travel, both movies highlight how time dilation separates the protagonist from the people they love on Earth.
Interstellar is more explicit with its portrayal of how Cooper’s daughter, Murph, ends up aging faster than him, and Cooper even watches her die towards the end. Project Hail Mary, on the other hand, keeps these aspects more subtle by capturing how Earth has completely changed since Grace left. Even though he considers returning home in the movie’s final scene, almost everyone he knew back home has either aged significantly or passed away.
As shown in the final scene, Earth, as a planet, also seems to have significantly cooled down because of the Astrophage consuming the Sun’s energy. It is not the same green and colorful planet Grace lived on before his space mission.
Like Cooper in Interstellar, Project Hail Mary‘s Grace achieves a selfless victory for Earth. Yet, he can never retain the life and the people he sacrificed everything to protect. Fortunately, just like Cooper turns to Edmunds Planet to reunite with Brand, Grace, too, finds an unlikely companion in Rocky, who helps him save stars, fists his bump, and makes him realize that even 189.3 years are not enough with someone you love.