The November 3the day the movie “Gojira” was released in 1954, fans celebrate the Godzilla Day. It’s not just a pop occasion: it’s an opportunity to ask a question that seems like a joke but instead opens very serious doors on the biology of giants, on the physics of fluids and on how science explains the limits of the possible. If we put on the lab coat and remove the nostalgia, what remains of the king of the kaijū? A dinosaur? A mutated reptile? A plausible amphibious creature? If we are to respond as scientists, the form bipedal terrestrial of the monster tens of meters high cannot stand: the square-cube law hey mechanical constraints they crush him. If we think about an animal amphibious or marine-dominantsome difficulties are alleviated: the physics of fluids grants something, while imposing other prices (pressures, decompression, breathing, energy). And the name? The academic culture of cinema reminds us that “Gojira is a symbol before an animal. But this very symbol, placed on the bench of conceptual experiments, helps us tell the story how science explains the impossible: through constraints — mathematical, physical, causal — which delimit the map of the living. The common thread is simple: science, when it talks about Godzilla, uses myth to explain because some life forms can exist and others cannot.
Film versions and biological interpretations over the years
The cinematic history of Godzilla has offered many different biological and symbolic interpretations over the years. In the Japanese Heisei series, Godzilla is depicted as ancient Godzillasaurusa prehistoric reptile survived extinction and mutated by nuclear testing; in the 1998 American version it becomes aenlarged marine iguana from French experiments in the Pacific; in the most recent saga of the MonsterVerse, it is instead a primordial titanidewhich emerged from the Permian e nourished by geothermal radiation.
Its physical appearance has also evolved: in modern films the dorsal spines change color, from bright blue to purple or pink, to symbolize different energetic or emotional states of the creature. But its biological identity remains deliberately ambiguous: in some versions it is male (the “King of Monsters”), in others a female capable of laying eggs, but in the Japanese language the term “Gojira” is neutralwithout grammatical gender. These variations do not erase the scientific dimension of the myth: they rather show how pop culture re-elaborates, from time to time, evolutionary hypotheses and fantastic mutations that real science can analyze as metaphors for our biological and technological limitations.
The voice of Oxford Bibliographies on Godzilla frames the 1954 film as a global turning point of monster cinema and visual culture: a character capable of spanning decades, formats, countries and reinterpretations. This framework is useful for two things: first, remembering that the animal “Godzilla” was born as powerful metaphor; second, take the biological question seriously without confusing the symbol with zoology.
A “real” relative of Godzilla: the dinosaur called Gojirasaurus quayi
Paleontology gives us a concrete basis. In 1997, Kenneth Carpenter described in detail a large Triassic theropod from New Mexico and named it Gojirasaurus quayi: an estimated length of approximately 5.5 metres, serrated teeth, robust hind limbs, tail important for balance. An early predator by Upper Triassic standards, and – a non-trivial detail – still immature at death, therefore with margins for growth. Christopher Griffin’s rereading, twenty years later, places these “first giants” in a broader evolutionary framework: already in the Triassic the neotheropods they explore larger sizesalthough rare and often represented by young individuals. In other words: nature really “proved” large, bipedal forms, but within certain limits structural.
Why giants collapse: when mathematics dictates the law to the body
Here a key concept comes into play that the philosopher of science Lauren Ross proposes as an “explanation by constraints”: there are mathematical, physical law and causal constraints which do not “switch on” a phenomenon, but they delimit what can exist. Godzilla is the perfect example to understand the mathematical constraint called square-cube law: if we double the linear dimensions of an animal, its mass grows with the cubebut the sections of bones and muscles only with the square. Result: the mass increases faster than the capacity to support it. And this is a limit of the possible.
The (serious) numbers on Godzilla
At the end of the 1990s Per Christiansen, a zoologist, tries to estimate mass and biomechanical plausibility of the cinematic Godzilla using a scale model and Archimedes’ principle (the same one used for real dinosaurs).
The accounts are merciless. Depending on the height chosen in the films, Christiansen comes up with rough estimates of Godzilla’s size and weight. For a height of approx 61 mthe monster should weigh around seven thousand (≈ 7058) tons. Assuming instead a height of approx 91.5m, it would weigh more than twenty-three thousand (≈ 23,822) tons.
With similar loads, locomotion terrestrial biped becomes a nightmare: limbs and muscles result undersized to move that mass “at a running pace”, even “at a walk”. Interesting paradox highlighted by Christiansen: the classic Japanese version, stockier and slowerit turns out biomechanically less absurd of the lean and very fast version of certain Western filmography.
Godzilla “works” better if it is (also) marine
The mainland is merciless with giants, the sea it is a little less so. There Archimedean push lightens loads on bones and muscles. On this ground, Nicolas Dietrich offers a brilliant and quantitative analysis taking inspiration from the film Godzilla Minus One. The idea of the film is: bonding freon tanks to the monster’s body, make it go down to 1,500 m of depth and then lift it up abruptly, trusting in the decompression lethal.
Dietrich sets up the problem as he would in the laboratory: he hypothesizes for Godzilla ~20,000 tons of mass and density ~800 kg/m³ (“semi-aquatic” value which would make it basically floating), it assumes 50 L tanks and known properties of freon (liquid ~1,174 kg/m³gas ~5 kg/m³), applies laws of buoyancy, thermodynamics And Boyle. The conclusion is twofold:
- in logistical terms it would be necessary tounlikely army of cylinders to overcome the thrust;
- to 1,500 m the pressure is ~14.7 MPa: a truly adapted creature (like large marine mammals, by analogy in principle) could be survive the deep phase e mitigate damage from ascent.
The point isn’t “Godzilla exists”: it’s that in water some conditions become more defensible compared to the completely terrestrial structure. The ocean, as a constraint physical-causal, channel the possibilities of the body.
Biology remains skeptical about “radiation mutation”
The original narrative ties Godzilla to the radiation. Here the science is cold: ionizing exposure, in the real world, does not orchestrate coordinated mutations capable of generating structures and organs in a functional macroscale (most often causes lethal or deleterious harm). Christiansen also highlights this, reasoning about growth and physiology insurmountable obstacles for a terrestrial reptile of similar dimensions: metabolism, oxygen supply, thermoregulation. The metaphor remains very powerful, the biological plausibility, not.
