That’s interesting, like you say, there’s not much room in there for much air, I’m not volunteering to be CO2 poinsoned in the name of science
You wouldn't like it much. I've never tried hypercapnia at atmospheric pressure but I've done it a few times under the sea.
Not sure how narcotic it is up here but inert gas narcosis can be lots of fun. Nitrous oxide, for example, is what they give birthing women to dull the pain just until it's too late to opt for the expensive Pethidine. Laughing gas - the modern version is used to make your kids woozy as their unwanted teeth are dragged from their skulls then they get to keep a bubblegum flavoured nasal mask as a souvenir to show the Tooth Fairy. I also made the mistake of pointing out to my kids that it's the propellant for that squirty cream so if you leave the tin squirty-end uppermost then just take a good blast on the gas you get a good head-rush and next time you want frothy cream you get a milky dribble.
Nitrogen narcosis is equally fun but it's a little more dangerous as it's difficult to achieve in your kitchen or with anything you might find in the fridge. The air you're breathing now is approximately 80% Nitrogen and 20% Oxygen so if the pressure is 1 bar your partial pressure (PO2) is 0.2 bar and your PN2 is 0.8 bar. Descend ten metres under water and you add a bar of water pressure so your PO2 is now 0.4 bar and your PN2 is now 1.6 bar, descend another 10m and you get another bar and so on. Get to a PN2 of about 2 bar and you feel like you've stopped off on the way down for a couple of pints and as you carry on things only get worse. This is why divers add helium to the breathing mix but this brings another world of problems that, were you suitably stoned, you'd likely not care about. 'The narcs' is quite nice though bad for the memory and it's not uncommon to to return from a deep air dive wondering what just happened but overdose on CO2 and it's not nice at all.
The usual cause of this is breathing too heavily at depth. The lungs are very well designed to take in normal air, swill it about awhile to let all the gas exchanging go on in the alveoli, the smallest spaces in the lungs, then throw the whole lot out again before sucking in a fresh batch. This doesn't work so well at depth, though, because the gas is much denser and heading towards becoming a liquid so it doesn't swirl about as nature intended it just washes in and out without doing its job of providing O2 and removing CO2. At this point your body spots the buildup of CO2 in your blood and commands that you breathe harder and faster and this just makes matters worse. Now the gas is washing in and out even faster making your chest muscles and diaphragm work harder and thereby producing more CO2 - it's a vicious circle and supreme control is needed to override the body's natural system and take long, tidal breaths until you've off-gassed the CO2 at which point things will slowly return to normal.
Now I've no idea how far you can reproduce the symptoms at 1 bar with a fighter pilot's mask and a bunch of heavy breathing but if you can get anywhere near it'll befuddle your brain in a most unpleasant way. Hypercapnia under water brought on paranoia and the terrors for me - I once convinced myself there was a shark hiding in a hole whereas it would have been forty willing virgins on Nitrogen so, by all means, subject yourself and we'll experiment on you in the workshop. The first test will be making tea for an entire Saturday crew whilst off your face on CO2.
I'm only a plumber from Cannock...
"As to reward, my profession is its own reward;" Sherlock Holmes.
'Sometimes you gotta be an S.O.B if you wanna make a dream reality' Mark Knopfler
Presumably it was only to carry a radio mic if he did.
but seriously, I think it was only for the radio, as the only pictures I’ve seen show no tube attached.
