The Real Science of Breathing Underwater Like Aquaman
Most human beings will take their ability to breathe air as a given, and unless they possess a keen interest in marine biology, will never stop to compare how humans and aquatic life harvest oxygen to stay alive. On a broad level, the fact is that most marine mammals (to keep this comparison simple) effectively "breathe" water in the same way we breathe air already. Where our lungs are designed to absorb the small amounts of oxygen and exhale the rest, marine animals like sharks, dolphins, and whales absorb oxygen from water and exhale the rest. So where is the difference? Why can't humans inhale water, and extract oxygen from it, instead?
Well, we actually can. And believe it or not, we've been able to do it for decades. As far back as the days when James Cameron was filming The Abyss, in which super-deep sea divers breathed "liquid air" to keep themselves from being crushed under the water pressure. And when the film showed a character submerge a pet rat in this "liquid air" until it started to inhale, animal rights groups went into a frenzy.
Clearly the filmmakers drowned a rat on film, to "prove" this science fiction subplot... right?
Wrong. The rat really was breathing an oxygen-rich liquid, once the instinctive panic subsided and its tiny brain realized a rat's lungs can absorb oxygen from liquids, just as the film's characters claimed. And after the rat went for its swim, letting the liquid drain from its lungs to be replaced by air once more was also just as real as it seemed. The film was sharing with moviegoers the very real experiments being conducted at the time, which make the idea of a human being breathing water plausible.
So... why aren't we? Why are Atlanteans like Aquaman still special? There's actually two major problems that Atlanteans in DC's Universe would have to have solved.
- The oxygen-rich version of breathable liquid humans need doesn't occur naturally, and
- Our lungs aren't made to easily switch from air to liquid
For breathing water to keep a human being alive on a chemical level, H2O is simply too much H, not enough O. And to function properly after breathing liquid for any amount of time, our lungs would need to be designed for both, and they're not. It puts a strain on human lungs that air doesn't, and requires serious recovery time. A problem Atlanteans, even half-Atlanteans like Arthur, don't have to contend with.
Given the real science, and the physiological barriers us humans can't overcome, it makes sense that Wan's explanation for Atlanteans hinges specifically on evolution:
In our story Atlanteans, because they were surface-dwellers at one point, they evolved slightly different. So we used that to differentiate a caste system. Like the high-born evolved slightly different to the people lower than them.
Fans have already gotten some looks at Aquaman's less-evolved descendants of Atlantis in marketing, but if the science isn't sound, it is at least plausible, or easy to imagine. The number of Atlanteans who perished when Atlantis fell into the ocean isn't known just yet. Those who survived had the fortitude to endure both air and water, and the lungs to take the necessary oxygen from both.
Did the Atlanteans who could breathe only water form a lower class, confined to the seas? Does Arthur's human father make him better suited to survive, and thrive in the air than the Atlanteans he will be fighting for the throne? And most importantly, does his shared ancestry make water-vomiting an unnecessary buzz kill?
For those answers, we'll have to wait until Aquaman hits theaters. Until then, be sure to read the rest of our coverage and descriptions of the Aquaman footage we saw during our visit.
- Aquaman (2018) release date: Dec 21, 2018