What?
Fluid that you inhale during deep diving sessions.
Where seen?
In science fiction epic The Abyss (1989) Bud Brigman (played by Ed Harris) uses a rosy liquid that allows you to breathe during a deep-sea dive.
How close are we?
He doesn’t look very relaxed, the rat that Marine Monk in The Abyss is submerged in a container of pink liquid. He struggles for a moment, as if he’s going to choke, but then he just keeps breathing, mouth open demonstratively.
No special effects, it turns out: The rat in that scene is actually breathing fluid. “We consulted with experts and bought liquid at $400 a gallon (3.8 liters),” Van Ling, who worked on the film, wrote in 1989. in the Los Angeles Times† “The rat survived.”
Director James Cameron was inspired by a lecture he attended as a teenager by Francis Falejczyk, a former U.S. Navy diver and the first human to breathe through liquid. Falejczyk did develop pneumonia after it proved difficult to remove the stuff from his lungs again.
He underwent that procedure with Johannes Klystra and Peter Bennet, affiliated with the American Duke University. Their idea was simple. Although we can’t get oxygen from normal liquids, the reason you suffocate in water, you can if you dissolve an extreme amount of oxygen in it: the Abyss method.
But why would you? The reason, for divers at least, is simple. During a deep-sea dive, inhaled nitrogen and helium dissolve in your blood under the increasing pressure, a bit like carbon dioxide is dissolved in a bottle of cola. Then go up and it’s like opening that Coke bottle. Also, climb too fast and it’s like shaking that bottle first: the bubbling is then so violent that you can die from it. That is why so far more people have walked on the moon (12) than have dived deeper than 300 meters in the ocean without a vehicle or pressure suit (7).
Breathe through a liquid, however, and the pressure in the lungs rises much less. The drinking problem when coming up does not arise then. During experiments, several researchers proved that liquid breathing was safe in small mammals and later also in, among others, lambs and dogs. Still, even after it was improved in response to Falejczyk’s pneumonia experience, the procedure remained difficult in humans.
When people ‘exhale’, people can hardly lose any carbon dioxide in the liquid, which accumulates in the body and causes damage there. Nevertheless, variants of the principle have worked as experimental methods since the 1990s treatment method Bee premature babies and with adult people with lung disorders† Partly because the technique did not perform better than already available treatments, it was never possible to take the last step towards larger-scale use.
Even with divers, breathing liquid has not yet proved practical, despite attempts to artificial gills to design that, connected to the human bloodstream, reduces the CO2 vaporize directly from your body. The deep sea therefore remains even more inaccessible than the gray grit of the moon.