Just thinking about that outcome yesterday caused my blood pressure to skyrocket. Dark, cold, cramped, fetid, hungry, thirsty, knowing oxygen is running out.

In that scenario, as long as they could keep CO2 levels down, running out of oxygen isn't so bad (ignoring the other troubles). The human body can't detect a lack of oxygen, you just get tired and light headed and pass out.

Yes, but as you hinted at the human body can detect a rise in CO2 levels and it doesn't take much for things to start getting really uncomfortable and fast. To your point, if you could somehow manage the CO2 levels then you would just peacefully fall asleep and die.

i understand what you are basing your statement on (a cleaner version would be asphyxiation by breathing an inert gas) but you are very wrong. as a matter of fact people with an impaired amygdala who can't experience fear will panic when forced to breathe co2. also your breathing will get very shallow and cause co2 to accumulate triggering those very receptors you argue will stay silent.

https://www.nature.com/articles/nature.2013.12350

You are arguing for the exact same thing as the person you’re replying to—while attempting to disagree with them. They said that provided you can keep CO2 levels down, lack of oxygen will cause drowsiness and cause you to pass out. This is true.

You then argued that breathing increased levels of CO2 will trigger survival instincts. This is also true, and exactly what grandparent said.

> while attempting to disagree with them

or you're just projecting your own character on someone you don't know?

That's not what they did at all

But kids and people die regularly due to having a barbeque thing lit in a close space and the coals consume the oxygen and make CO2.

Wouldn't that wake them up?

I also assumed that too much CO2 fast is the key not the super slow version of what those people in the sub have experienced

what you mean is CO - not CO2

What the does that have to do with what OP said?

OP, correctly, pointed out that we don't detect the lack of O2, we detect a buildup of CO2 (because it causes respiratory acidosis). If the CO2 is removed, there's nothing to cause the panic response, the situation itself notwithstanding.

It's still nea that it works with an impaired amygdala, though.

first of all - the co2 isn't removed ...

It is, they had CO2 scrubbers

but not endlessly. those scrubbers are saturated after a while. that's the whole point. otherwise suffocation wouldn't be a threat to begin with.

why do i have to argue here with so many people about something so simple to understand?

The CO2 scrubbers were in masks which could be replaced and there was enough for 96 hours

how is that even relevant to the question here? i'm out, have a good day

It's called a hypothetical.

> The human body can't detect a lack of oxygen

Unless you know you are trapped and running out of oxygen.

No, you really won't notice even if you know it's coming.

https://www.youtube.com/watch?v=kUfF2MTnqAw

These kind of long, agonizing, pointless deaths are all too common when dealing with the ocean.

There was a horrifying case after Pearl Harbor where bodies were found in the airpocket of the USS West Virginia. They had flashlights with batteries and fresh water and had marked off 16 days on a calendar.

Legend has it that sailors could hear banging for weeks knowing they could not cut through the thick battleship armor in time and just drowned out the noise.

an article about it: https://www.seattletimes.com/nation-world/16-days-to-die-at-...

A sometime co-worker's father was on a salvage crew at Pearl Harbor, and apparently heard the banging.

Then again, the rover would have found the sub from the location even if it were intact, and there could have been a small chance of survival since they had the equipment. Hope is more important than agony.

What would be worse a catastrophic collapse deep down in the sea or a sudden depressurization high above in the sky around the Armstrong limit?

The latter clearly as you’d definitely have a longer time of being conscious.

One would survive at the Armstrong limit for much longer indeed:

> Exposure to pressure below this limit results in a rapid loss of consciousness, followed by a series of changes to cardiovascular and neurological functions, and eventually death, unless pressure is restored within 60–90 seconds. [0]

[0] http://www.geoffreylandis.com/vacuum.html

The pressure difference between complete vacuum and sea level is one atm. At the depth of the titanic, the difference is about 375 times that.

Implosion at 400 atm probably takes a fraction of a second, with catastrophic decompression of 1 atm you’ll be conscious probably for about a minute.

Above the Armstrong limit you're looking at 9-15 seconds of useful consciousness. (The time you are conscious enough to take actions to save yourself.)

When a deep sub implodes you're going to be hit by water moving at the speed of sound in said water (1,500m/s, considerably faster than in air.) That's far above the speed of nerve impulses, there's no way a pain signal could reach the brain before there isn't a brain left to get the signal.

I’ll still take about 1/1000th of a second or so over upto 10 seconds of contemplating my faith.

Especially in the case where I’ve drugged one of my children to come with me.

Somewhere a redditor did the math and I believe it would have taken 24ms for the glass to break and the water to rush in. Instant death if it was indeed the glass.

The porthole windows on deep submersibles are conical plugs. They don't break. Either a seal leaked or the carbon fiber failed.

Maybe on competently assembled subs. All bets are off on this one.

Probably was the porthole. It looks like the view port was rated for 1,300 meters. (They were descending to 4,000 meters) An engineer even warned them of the issue, and was fired. I suppose they didn't want to spend the money to develop an adequate one.

Just how instant is that death? Do you die from quickly drowning in the water or is the water pressure enough to also crush your skull to make sure you die without having the chance to feel anything?

Guillotined people can still be alive and feel about 30 second safter their head has been removed from their body.

The pressure at that depth is something like 5000 psi. You're literally dead before your brain has time to comprehend what's happening.

not if the leak leaked for an extended period without ripping open ... then pressure would build up very slowly.

You should read up down the properties of carbon fiber

Water pressure crushes you faster than signals can run from your nerves to your brain.

I have been in a car accident that, in the instant of impact, felt indistinguishable from an explosion, too fast to process anything. I imagine the massive pressure change would cause near-instant incapacitation if not death.

i would expect the impact of the water rushing in that quickly to knock everyone out.

Instant.

Imagine a Ford F150 sitting on every square inch of your body.

It's actually easier to imagine water than trucks

Maybe not for Americans. Actually, converting units to "inches" and "F-150s" is probably the most USA-friendly framing possible.

Is that with Imperial cup holders or metric cup holders ?

Lungs collapse instantly

Both the water pressure, and the submarine material around you. It'd be more akin to your entire body would nearly instantly be squished in all 3 dimensions, with non-compressible items (bulk-head/steel) also inhabiting the same space.

I reckon its instant death. If the sub imploded or the carbon fibre hull failed, then it means large amounts of debris come rushing to you very quickly.

I don't think there will be any bodies to recover.

> Do you die from quickly drowning in the water

logically not in this case. at that point where the water level is sufficient to make someone drown the remaining air would be compressed to several hundred atmospheres pressure.

Who told you that about the guillotine? They'd have zero blood pressure, how do you imagine they'd be conscious?

Iirc they did tests where people agreed to blink a certain number of times etc.

Strange, they never asked those condemned to actually utter some sound or mimic something, isn't it? Well, that's because residual muscle twitch is not controlled and is not conscious. Rapid drop of blood pressure renders the person (well, their head, in that case) unconscious within a couple seconds and it is downhill from there.

> Well, that's because residual muscle twitch is not controlled and is not conscious

And because making sounds without lungs attached to your throat is kinda hard

It would be more like dying from a shockwave from a massive explosives blast. You're going to turn entirely to jelly. Within a few ms there will be nothing left working properly.

I did read somewhere (I don't remember exactly where) that when there is an implosion at great depth the air in the submarine is compressed so quickly that anything flammable (specifically human bodies, plastics, etc) would burn up instantly. So it's a bit like the explosion of the fuel-air mixture in a diesel engine.

Makes sense.

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

>Just how instant is that death?

Similar to the Arbogast in The Expanse, but even greater disassembly.

I mean, unless it imploded after a horrible fire or something.