Comment by extraduder_ire | Hacker News Reader

Comment by extraduder_ire | Hacker News Reader

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>Except for helium, no other gas exists which does not have some form narcotic effect at higher pressures.

According to something mentioned in passing in a Scott Manley (amateur space youtuber) video about deep-sea diving: at high enough pressures you'll get similar effects from helium. It's thought that you can avoid this by subbing out the helium for hydrogen, but nobody so far has been insane enough to try.

I assume liquid breading is much easier at that point.

>The interesting thing about this research is that it sort of makes sense, and yet is very surprising. We’re basically continuously narked, we’re just so used to it we don’t even know.

I'd be interested in knowing how people are mentally when they're in spacewalk/Mir conditions. (1/3rd atmosphere, pure oxygen.)

> It's thought that you can avoid this by subbing out the helium for hydrogen, but nobody so far has been insane enough to try.

It's reportedly been done very recently using a rebreather (https://gue.com/blog/n1-the-inside-story-of-the-first-ever-h...).

Prior to that, in 1992, there was the French COMEX-sponsored HYDRA 10 experiment that saw Théo Mavrostomos dry-dive in a chamber to 701 meters (71.1 bars) - the world's absolute saturation dive depth record. Though that experiment used "only" 20% H2 (https://www.newscientist.com/article/mg13618493-000-technolo...).

Reading that first article freaked the hell out of me, thanks.

Glad there's some people out there nuts enough to push the limits of this stuff. No idea why those people in new zealand don't use pressure suits to dive in that hole though.

I only have high school level chemistry, but if Helium is a noble gas it doesn't bond and so it can't have a narcotic effect, because it doesn't affect the chemistry of the brain

I wonder if you could use argon instead then.

And yet, argon is more narcotic than nitrogen:

https://en.m.wikipedia.org/wiki/Nitrogen_narcosis

The narcotic effects of inhaled gasses don't seem to have anything to do with chemical bonds. There's something else going on. Even some noble gasses like argon are highly narcotic.

It's narcotic effect comes from lipid solubility (and because it basically crowds out other gases - likely oxygen - needed for chemical reactions). So basically, because it's an inert gas it prevents some reactions.

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