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There is an enchanted thingy at the top of a mountain, and there is only one hero who can wield said thingy in order to save the world. The mountain is 5,000 meters in height and the atmospheric pressure is standard to earth. Our hero exists in the late medieval age and has no access to modern advancements (no modern air tanks to increase oxygen intake, or medicines), they are not pre-acclimatized and has no time for acclimatization. They must reach the top of the mountain as soon as possible or the world will perish. Assume warmth and hydration will not be issues.

What can they do in order to avoid altitude sickness to an extent that they can still function and succeed? Is this even possible?

Greg Martin
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Silvirs
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    How did that thingy get up there? And does it really have to be an Everest? Wouldn't a Mount Blanc be enough? It's hard enough to get up to 4000 m, but probably feasible given the technology level. – Erik Oct 22 '20 at 08:32
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    Editing a question to invalidate existing good answers is generally considered rude. If you want to ask a different question the ask a different question. – AlexP Oct 22 '20 at 12:24
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    A "killer mountain" doesn't need to be Everest, K2, or Anconcauga -- the Matterhorn was a killer mountain, and it's less than 4500m altitude (significantly less than that from the base). – Zeiss Ikon Oct 22 '20 at 12:24
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    Where is our hero from? In real life people from mountain regions have adapted to high altitudes, so the stereotypical shepherd boy from Nepal, Tibet or Andes might have a chance or at least do better than equally stereotypical knights from the capital city. – ojs Oct 22 '20 at 16:02
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    5000 m = 16,400 ft, which is not much higher than the US's Mt. Whitney, which is a pretty stiff hike from the east side (you can drive to 8600 ft) or a several day backpack from the west, or Pike's Peak, which is a Sunday drive (or a stiff day hike from Manitou Springs). How steep is your mountain (does it require technical climbing, or just hiking), what elevation does your hero live at, and what sort of shape is s/he in? – jamesqf Oct 22 '20 at 16:12
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    Is your hero a fit (action) hero, a physically decrepit wizard, or someone in good physical condition, experienced and thus a little advanced in years. The third may actually be the best choice - taking the climb a little slower and more wisely than the first, but capable. – Chris H Oct 22 '20 at 16:24
  • there is people who suffer from altitude sickness and people who mostly don't. I've been as high as 4000m and some more, and I didn't accuse anything more than shorter than usual breath – carlo Oct 22 '20 at 17:47
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    How is it fair to ask for hard science, and "Assume warmth and hydration will not be issues."

    If the thingy on the mountain is enchanted, why can the hero not use enchantment?

    With neither air-ranks or acclimatization, he looks like a melted snowflake but wait! How is "as soon as possible" restrictive? ASAP should give all the time that's needed.

     – Robbie Goodwin Oct 22 '20 at 21:08
  • Kilimanjaro is 900m higher, and the ascend from 1700m and getting back there has been done in under ten hours. – Karl Oct 23 '20 at 10:30
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    Qat. Coca leaf. – J... Oct 23 '20 at 14:49
  • Keeping hydrated will go along way to help mitigate the high altitude sickness. Not dealing with freezing temperatures will also help. – Michael Richardson Oct 23 '20 at 21:01

7 Answers7

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5000m is well below the "zone of death" where oxygen supplementation is required, and there were passes that high used in ancient times, so it's certainly feasible for people to operate at that altitude without special equipment. In the acclimatization section that you linked to, it talks about only increasing where one sleeps by 300m a day, above 2400m:

The rule of thumb is to ascend no more than 300 m (1,000 ft) per day to sleep. That is, one can climb from 3,000 m (9,800 ft) (70 kPa or 0.69 atm) to 4,500 m (15,000 ft) (58 kPa or 0.57 atm) in one day, but one should then descend back to 3,300 m (10,800 ft) (67.5 kPa or 0.666 atm) to sleep.

Basically, the key questions are: "how high can your hero climb in one day", and "how much time do they actually have to get up there"? Saying "as soon as possible" is one thing, but if you're thinking "hours" then they're just going to have to push to the top and chance it. But a 5000m climb is not really a one-day deal just from a "people can't climb mountains that fast" standpoint (the example above mentions acclimatized, modern climbers going up 1500m in one day before returning back down 1200m).

If we assume they can take a few days, then they can probably get up there safely without much issue. Push up to ~2500m, spend the night, push higher up the mountain each day, retreat back down to somewhat higher basecamps each evening, and they'll hit the top at some point. If the magical doodad gives them the ability to spend the night up at the summit safely or some magic means of transportation, they could probably shave a day off their trip since they don't have to leave time to come back down to camp.

Greg Martin
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Salda007
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  • You are very correct, 5000m is well within the survivable range, although I intended my question to deal with surviving the "Death Zone." I don't know where I got the 5000 number, but I've edited my question to 9000m. I do, however, appreciate your thorough answer. – Silvirs Oct 22 '20 at 07:10
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    Given that the "sleep 300m higher" rule is about risk reduction, it can probably be ignored in the 5000m case - less knowledge and more acceptance of the risk in the setting, and sufficient desperation to override precautions anyway – Chris H Oct 22 '20 at 16:20
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    Also, a true Hero will think "Dying in my sleep after saving the world? Acceptable." – Stig Hemmer Oct 23 '20 at 07:52
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    Mount Whitney isn't that different from the mountain described in the question. The usual route is to hike to Whitney Portal (2500 meters) on the first day, then (if you're doing it in a single day) charge for the summit and try to get back down before altitude sickness becomes a problem. A 5000-meter mountain is about the tallest you can do this on -- any taller, and you can't get to the top and back in time (Whitney is 4421 meters, and the summit push takes 12-18 hours). – Mark Oct 24 '20 at 01:08
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Coca leaves, the placebo effect, and motivation

These have been used historically to help mitigate altitude sickness. Can be refined in various ways to increase potency and taste, including into caramels and other tasty things. (Refining it too much will make cocaine, so some middle ground might be ideal).

There isn't any scientific evidence backing this up (studies show no correlation in blind trials), but the knowledge that it's been used for generations and locals swear by it can induce a placebo effect, which is beneficial.

Behaviour at altitude is measured in "Time of useful consciousness" which for your hero at 5000m will be about 30 minutes. This isn't 30 minutes until death, it's 30 minutes of making sensible decisions. If the top of the mountain is a gentle slope and not a cliff face, every last fibre of their being is motivated to get there, they're currently walking there and don't need to change the pattern of "left foot right foot", and they have to do nothing when there except be present (or flop on some "abort" button, that's not behind a door or anything tricky to open while hypoxic), and believes they've taken something to dramatically increase his chances of surviving. They might just get there.

Glorfindel
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Ash
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You world is doomed

Even for modern capabilites mountain of 9000м would be unreachable without pressure equipment of some sort. 1km height differnce with now-highest mountain is a lot. It makes the difference. A trained person can breath at 8000 (33kPa), at 9000 (30kPa) they can't.

That 3kPa change puts the partial oxygen pressure (from 33 * 0.22 = 7.2kPa to 30 * 0.22 = 6,6kPa) to far bellow chemical limit (8kPa). 1kPa of pressure can be negated by special technic of breathing (shortly holding breath and increasing its pressure with you muscles on each sigh). But 1,5 would be unachivable by that. (Yes, lungs can create up to 10kPa of excess pressure, when, say, filling airbaloon, but you can't fill airboolons all around the clock).

Besides this +1km is quite a large distance by it own - so human would need to stay in "death zone" far longer than they can survive it.

So your medieval untrained person can't reach this height by any means in a hard-science world.

I suggest you to lower height to 7000-7500 meters wich is reachable by highly trained climber with support team only, but still does not require any superhuman abilities.

For that height other answers apply: willpower, luck (tons of it), trained body - your hero might be sailor (climbing skill) with long history of diving for pearls (breathing skill).

Greg Martin
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ksbes
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  • OP states the altitude is 5,000m. – The Square-Cube Law Oct 22 '20 at 12:50
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    It was rolled back because it invalidated another answer. OP stated in a comment, that he intended it to be higher but mistyped. – infinitezero Oct 22 '20 at 12:54
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    People have summitted Everest (just under 8850m) without supplemental oxygen. Does the final 150 meters make that big a difference? – chepner Oct 22 '20 at 16:38
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    @chepner Everest is never climbed on a "get to the top ASAP" basis. Base camp is at 5600m, and getting there takes nine days with two full day rests along the way. Then you still have 3200m+ to climb. – Zeiss Ikon Oct 22 '20 at 19:38
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    @ZeissIkon That has nothing to do with the claim that it is impossible to breathe at 9000m without pressure equipment. – chepner Oct 22 '20 at 19:40
  • @chepner I was replying only to your statement that people have summited Everest without oxygen, as being irrelevant to the question even in the 9000m form that I originally saw (before it was rolled back to 5000 m). – Zeiss Ikon Oct 23 '20 at 11:08
  • @ZeissIkon Yes, it's an issue for the hero in the OP, who is stated to not have time to acclimate. But the answer doesn't put its claim in that context. – chepner Oct 23 '20 at 12:20
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We have managed to reach Mt. Everest (8850m) without supplemental oxygen.

However, this was done by superbly trained and ultimately fit experienced climbers. And it was done with a support staff of thousands. Remember its not only the final climber, its not only his 10-12 person climbing support team, or the other two equally large support teams. It is also the 200 or so that stock the base camp from the nearest village. Which village only exists because it is a supply line for Everest. Which village is totally populated by a culture that is not only pre-acclimatized but also descendants from generations of high-altitude dwellers. Which village is kept stocked by the proceeds of an industrial modern economy with all the vehicles and infrastructure that goes along with that.

As the OP asks, for a single, untrained, late medieval age person who is not pre-acclimatized and has no time for acclimatization..

ab.so.lu.te.ly. no chance for 9000m

9000m requires both a skilled and acclimatized climbing team, and the infrastructure to make a supply chain for the climbers.( I know its been done 'solo' and without oxygen. Did that solo climber really lug all his gear, food etc. from sealevel, by himself?)

For the 5000m in the original question... Yes. Not at all easily, but possible. It depends on the climate and technical difficulty of the mountain. Does your hero have access to a support staff that can build a supply chain for him? He is a hero, we can assume he is in superb physical fitness. What sort of protective clothing does he have access to? Is there a local tribe that is pre-acclimatized to living at altitude, and is willing to assist our hero?

Refining the question down to just: Can a late medieval age person avoid or moderate altitude sickness, without taking the time for acclimatization? Not really: Late medieval is 1250 to 1500 AD. No knowledge of Oxygen, no means to make it without very heavy materials, no ways to store it. No knowledge whatsoever of actual medical treatment for altitude sickness.(which requires tailored steroids) Drugs that fortify the body/metabolism actually worsen your response to altitude sickness! So no opium or coke or junglefrog licking for you.

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    Messner has climbed Mount Everest solo, and without oxygen. https://en.wikipedia.org/wiki/Reinhold_Messner#Mount_Everest Of course he was sort of "fit". ;) – Karl Oct 23 '20 at 08:14
  • Coca leaf has been used for a very long time in South America, particularly for altitude sickness, so I'd take issue with that last sentence. Qat/Khat similarly. – J... Oct 23 '20 at 14:52
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We need to advance chemistry a little to get oxygen but perhaps not implausibly so in your context. I looked for chemical ways of producing oxygen ideally accessible to alchemists, but definitely without electricity (common chemical oxygen generators use electrolysis in their manufacture). While most of what I've suggested happened too late, much of it could have happened earlier.

Barium peroxide releases oxygen at low pressures (possibly requiring elevated temperatures, but possibly not).

Wikipedia says medieval alchemists knew about some barium compounds, such as baryte. Barium oxide was isolated in the 1770s, and that can be made into the peroxide by heating. Further heating will release oxygen. This was used to obtain oxygen via the Brin processbut that was in the 19th century, though it could probably have been developed considerably earlier: The pressure pumps required for the more efficient process could have been built by 1650, but heat would work. The downside is the BaO2 only gives you about 1/10 of its mass as oxygen - so you'd need to carry a lot if you carried the solid.

Maybe it wouldn't be too much of a stretch to use that air pump directly and carry compressed air, or oxygen-rich air produced using barium peroxide. The Magdeburg hemispheres were a demonstration of vacuum in 1654. If metal could be worked to keep pressure out, it could keep it in. I suggest that the metalwork was possible earlier, and the concept was what prevented earlier demonstrations.

If you could get to sodium peroxide you'd have something that reacts with CO2 to give O2 as used in rebreathers, but that may be a little too far. It is however much lighter than barium peroxide ("barium" is, after all, etymologically derived from the Greek for "heavy"). Potassium superoxide is another chemical oxygen generator, but potassium wasn't isolated until the 19th century and the intermediates are rather tricky to handle; hydrogen peroxide and various derivatives are similar too recent even if they could be made without electrolysis.

Chris H
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    If nothing else, this is meant to set a vaguely plausible lower limit on the technology levels required for supplemental oxygen. – Chris H Oct 22 '20 at 17:35
  • You'd need to carry "a lot" of solid BaO₂... but how much? versus how much gaseous O₂ (produced in a lab) if you could keep it pressurized? MountEverest.net gives me a wild-ass guess of 1L per minute, let's say 18 hours round trip, that's about 1000L O₂... So if our hero's backpack gets unwieldy around 50L, it'll have to hold up against a pressure of 20 atmospheres. Hmm, I should just link to https://worldbuilding.stackexchange.com/questions/25505/oxygen-cylinders-in-medieval-world/ because I'm sure my math is fuzzy. :) – Quuxplusone Oct 24 '20 at 20:48
  • @Quuxplusone I was working on that, and found such different numbers that I gave up - of course a very few people have managed with 0 supplemental oxygen. Plus is that litres at sea-level pressure when filled, or calculated at altitude. You'd definitely need to carry more weight of BaO2, or even the harder-to-make Na/Li oxides compared to O2 gas, but bronze gas cylinders would add a huge weight to the gaseous storage. Actually the cylinders would be relatively easy - they could be cast; metalworking for the valves would be the hard part. You need precision screw threads to hold a few atm. – Chris H Oct 24 '20 at 20:59
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    ... BTW 50L isn't unwieldy. My trekking backpack is 85L and would gain stuff on the outside - still, 100L would be 10 atm, and still hard to control - that;s the real advantage of solid storage.. – Chris H Oct 24 '20 at 21:00
  • "is that litres at sea-level"— I dunno, but assumed yes. 1000L O₂ at 1atm is like 1.5kg, so absolutely "bronze gas cylinders would add a huge weight" but at least the weight of the container is the only weight significant to this calculation. The big question is, how much would (a medieval container capable of taking 10 or 20atm pressure) weigh? Could it conceivably be leather instead of metal? https://i.imgur.com/JfuepMb.mp4 – Quuxplusone Oct 24 '20 at 21:17
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    @Quuxplusone leather could possibly hold the pressure, but I'm not sure if the seams could. And I doubt it could be sealed well enough. For comparison, car tyres are 2-4 atm, and racing bikes up to about 7 atm, held in by rubber – Chris H Oct 24 '20 at 21:48
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Why does the hero have to be the one doing the climbing?

The classic mistake of too many heroes is assuming they have to do everything themselves. A hero who knows their limitations and can delegate effectively would be much more effective.

Hire yourself a battalion of sherpas or the local equivalent. With enough money, you'll get people ready to risk their lives. Granted they'll know it could be a suicide mission, but for money and for the fame of saving the world you'll find people to do it. They'll all be fully acclimatised already and have years of training and expertise which the hero simply doesn't.

So the climbers hit the mountain. A large proportion of them die in the attempt, but a handful reach the summit, grab the weapon and head back down again with it.

The hero waits safely at base camp. The surviving sherpas finally reach the camp and give him the weapon. He saves the world. Job done.

Graham
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  • But in this version, the story wouldn't be about a hero who conquers an unassailable mountain in order to retrieve the sword that saves the world. It would be about a rich employer who hires heroes to do the hard work and then reaps their glory. – Schmuddi Oct 23 '20 at 08:10
  • @Schmuddi If the world needs saving, you'd better be practical about it! And if he's the only person who can use it, he's still doing his part after that. Think of Marvel. Nick Fury isn't close to the most powerful individual - but he's the big boss with the strategy. And in the Avengers, Cap isn't the most powerful individual there either - but he's the guy who the others trust to delegate tactics in a fight. Just for a couple of easy examples. You can still be heroic by delegating to other heroes. :) – Graham Oct 23 '20 at 08:35
  • Fair enough. But being the brains of the operation instead of the muscles will cost you in hero points. I'd wager that if you asked for Marvel heroes in Family Feud, Nick Fury would be rather low on the list if at all. – Schmuddi Oct 23 '20 at 09:14
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    @Schmuddi True - but at least the Earth is still there. If the Earth is destroyed because the hero doesn't know how to use crampons and an ice axe, no-one gets to go on Family Feud. – Graham Oct 23 '20 at 10:25
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The problem is a bit mixed up.

As it currently is written with the object at 5,000m you don't have a big problem. Based on my previous experiences at high altitude (I'm a hiker who likes mountains, but not a mountaineer) I would expect to be able to make that climb without serious issues.

It appears that at some point you changed this to the death zone and it's been reverted back. An unacclimated individual in the death zone doesn't suffer altitude sickness, they pass out and soon die. The time of useful consciousness at the bottom of the death zone is roughly 3 minutes, by the time you're up to that 9000m figure it's half that.

Loren Pechtel
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