Hacker News Reader

Comment by zoomablemind | Hacker News Reader

> "...They settled on liquid perfluorocarbons, which can absorb large amounts of oxygen and are often used as a blood substitute or to assist the ventilation of premature babies...."

Reminded me of the scene from an old underwater sci-fi flic (? was it 'The Abyss' https://m.imdb.com/title/tt0096754/), where the deep-divers had to learn how to 'breathe' the oxygenated liquid instead of air.

Speaking of liquid, there was also an example of 'fluid animation' (is it the term?), later also seen in Terminator 2 (the unkillable and self-reassembling T-1000) and other movies.

View on HN

Yes it was "The Abyss", see the rat scene: https://www.youtube.com/watch?v=H6hw4dGhm8Y

From https://en.wikipedia.org/wiki/The_Abyss "The breathing fluid used in the film actually exists but has only been thoroughly investigated in animals.[5] Over the previous 20 years it had been tested on several animals, who survived. The rat shown in the film was actually breathing fluid and survived unharmed"

https://en.wikipedia.org/wiki/Liquid_breathing

I could see a low pressure breathing fluid being advantageous for space travel. I wonder how long a mammal could live in that environment. Now if we can just retain our gills.

What's the point?

The human body can take vacuum fine if supported. The lung pressure lower limit is the required oxygen pressure plus the vapor pressure of water at body temperature plus the pressure of the carbon dioxide being expelled. Putting your oxygen in a liquid isn't going to change this minimum.

Liquid breathing is being looked into for high pressure environments, not low pressure environments. The human body has no problem with any high pressure it's ever been exposed to, the depth limit for diving is because the dose makes the poison--you eventually hit the point where anything you could put in your tanks is dangerous.

What are you talking about? The human body has enormous problems with high pressure.

You are referring to oxygen toxicity. There is far more to it than that. At great enough pressure, your body cannot expel CO2.

The point is forming an environment that is at low risk to depressurization while at the same time forming a radiation barrier.

Why do you need to be so hostile?

The idea of breathing one of these heavily oxygenated liquids has been around for a while and I believe even tested on live animals. I can’t remember if it was tested on humans.

In theory it all works and has great benefits for breathing in high pressure environments. In reality I believe the issues encountered were: getting past the feeling of drowning at the beginning, needing very strong lungs for even normal breathing rates, and then transitioning back to air being problematic.

> ...transitioning back to air being problematic.

Yeah, this seems to be quite an obstacle, giving the fact how long it may take for lungs to fully expectorate the mucus after a bout of pneumonia.

In this case, this gas would be injected directly into the rectum, so you could switch back to lungs as soon as the lungs were clear (or run both simultaneously). At least, that's the theory.

Liquid breathing has never been successfully tested in humans, or any large animal. It doesn't scale up well from small animals. The work of breathing is too high. It might be feasible at some point with external mechanical ventilation.

This reminded me of scene, from a sci-fi book (Arthur C. Clarke, maybe), about a naked race on the moon. The racers filled their lungs with some sort of oxygenated liquid.

Reply on news.ycombinator.com