Jamie Carey
From quantum mechanics to astrobiology, and from space travel to special relativity, Project Hail Mary draws on a range of concepts that even physics students might need to revisit. In a genre where scientific accuracy varies wildly, from the meticulous realism of Interstellar to the outright fantasy of Star Wars, Andy Weir faced a difficult balancing act: combining compelling, emotional storytelling with rigorous theoretical science. The question, then, is not just whether the science is impressive, but how accurately it reflects our current understanding of the universe.
The film opens with Ryland Grace, a disgraced molecular biologist whose research questioned whether life necessarily depends on water, being recruited to investigate a peculiar astronomical anomaly. A newly discovered microorganism known as “astrophage” is found to be draining energy from the Sun, causing it to dim and threatening a global climate catastrophe within decades.
At the heart of Astrophage’s abilities is a real concept from physics: mass–energy equivalence, first described by Albert Einstein. In simple terms, Einstein showed that mass and energy are interchangeable, meaning that mass can be converted into energy, and vice versa. This is captured in the famous equation, E = mc². Here, E represents energy, m is mass, and c is the speed of light. The key idea is that even a tiny amount of mass can produce an enormous amount of energy when converted. This idea underlies real phenomena such as nuclear reactions in stars, where small amounts of mass are continuously converted into vast quantities of energy.
However, Project Hail Mary takes this idea much further. Astrophage appears capable of converting mass into energy with near-perfect efficiency, something that, in reality, is only approached in extreme processes like matter-antimatter annihilation. No known biological system could perform such a conversion, making this one of the film’s biggest scientific leaps.
‘While the energy source itself is speculative, the broader constraints of space travel… are portrayed with a solid degree of realism.’
Despite the film’s questionable take on special relativity, one of the most impressive aspects of Project Hail Mary is its relatively grounded depiction of interstellar travel. Unlike many science fiction films, it avoids faster-than-light travel entirely, instead relying on a propulsion system powered by Astrophage.
While the energy source itself is speculative, the broader constraints of space travel (long durations, isolation, and the need for self-sufficiency) are portrayed with a solid degree of realism. The spacecraft’s use of rotational motion to simulate gravity is also physically sound, relying on centripetal force rather than fictional technology.
In contrast, Interstellar takes a different approach, blending rigorous physics with more speculative concepts. The film’s depiction of black holes and time dilation is rooted in Einstein’s theory of relativity and was even informed by physicist Kip Thorne. For example, the extreme time dilation experienced near the black hole Gargantua, where hours correspond to years on Earth, is a real consequence of strong gravitational fields. However, Interstellar ultimately relies on more theoretical ideas, such as wormholes enabling near-instantaneous travel across vast cosmic distances.
The key difference between the two lies in how they handle the limits of physics. Project Hail Mary respects the fundamental barrier that nothing can travel faster than light, instead asking how far humanity could go if given a sufficiently powerful (albeit fictional) energy source. Interstellar, on the other hand, preserves known physics locally, accurately portraying relativity and black hole behaviour, but circumvents distance altogether through theoretical constructs that remain debated among theoretical physicists. In this sense, Project Hail Mary is more conservative in its treatment of space travel, while Interstellar is more ambitious; grounded in real physics, but willing to speculate on phenomena that may never be physically realised.
While Project Hail Mary does incorporate relativistic time dilation, its role is more subtle than in Interstellar. Grace acknowledges that travelling at relativistic speeds will cause time to pass more slowly for him than on Earth, meaning that any return journey would take him into a distant future. In this sense, time dilation does shape the broader implications of the mission, particularly the likelihood that he will never return to the world he left behind. Grace uses the time dilation equation to deduce that 12 years pass on Earth during his 4-year voyage to Tau Ceti. The equation, derived by Einstein, shows that time measured by someone moving is different to the time measured by someone who isn’t moving. Basically, if you are moving faster, such as Grace travelling in a high-speed rocket, you experience “less” time relative to someone on Earth. However, unlike Interstellar, where time dilation is central to both the plot and its emotional impact, in Project Hail Mary, it remains a background constraint rather than a driving force.
Beyond relativity, space travel, and mass–energy equivalence, Project Hail Mary also draws on several other areas of science, most notably astrobiology, orbital mechanics, and spacecraft engineering. The film explores the idea that life may not be limited to Earth-like conditions, suggesting that organisms could evolve in radically different environments. This is reflected in the depiction of alien life forms that are chemically and structurally unlike terrestrial biology, aligning with the scientific view that life elsewhere in the universe may not necessarily be water-based or carbon-identical.
The film also relies heavily on realistic orbital mechanics and classical Newtonian physics. Spacecraft motion is governed by inertia and gravitational forces rather than any form of artificial “space drag,” and interstellar travel is treated as a problem of energy, velocity, and trajectory rather than cinematic shortcuts. In addition, the engineering challenges of long-duration spaceflight, such as life support, radiation exposure, and autonomous system reliability, are treated with a strong degree of realism, reflecting genuine constraints faced in real-world space exploration research conducted by organisations such as NASA.
However, these accurate frameworks ultimately sit on top of a single highly speculative foundation: the existence of astrophage. While the surrounding physics is often consistent with current scientific understanding, the biological and energetic properties of this organism require mechanisms that go far beyond known chemistry, thermodynamics, and particle physics.
‘Ultimately, the film can be described as scientifically coherent rather than strictly scientifically accurate’
Overall, Project Hail Mary presents a scientifically grounded depiction of space travel and problem-solving, particularly in its use of real physics principles such as orbital mechanics, time dilation, and energy constraints. Its greatest strength lies not in strict scientific accuracy across all domains, but in its consistent application of real scientific thinking where observation, experimentation, and iterative problem-solving are used in a way that closely mirrors actual scientific methodology.
However, the story ultimately depends on a single major speculative assumption: the existence of astrophage and its ability to manipulate energy at a level far beyond any known physical or biological system. While this represents a significant departure from established science, it is largely contained, allowing the rest of the narrative to remain internally consistent and physically plausible.
Ultimately, the film can be described as scientifically coherent rather than strictly scientifically accurate: a work that remains firmly rooted in real physics, while allowing one major exception to drive its narrative forward.
But it’s still a really good movie, isn’t it?
Jamie Carey
Featured image courtesy of Marek Pavlik via Pexels. Image use license found here . No changes were made to this image.
For more content including uni news, reviews, entertainment, lifestyle, features and so much more, follow us on Twitter and Instagram, and like our Facebook page for more articles and information on how to get involved.
