Water and the Peak of Mount Everest

[Der Anfang]

So, how exactly does water behave on the peak of mount everest? It's roughly 8848 m above sea level... so pressure is only about 30 kPa, maybe less. Water boils at higher altitudes on Earth, but it's also much colder up there. 

Even in space or on Mars, I'm not really sure when water is supposed to sublimate or freeze... do we know how water nehaves exactly on the peak of this mountain?

[Dr. Jet]

Concidering 30 kPa is 0.29 atm, water will boil at near 68°.

[Jeanjvs]

Wikipedia states that "on top of Mount Everest, at 8,848 m (29,029 ft) elevation, the pressure is about 34 kPa and the boiling point of water is 71 °C".

Here https://en.wikipedia.org/wiki/Boiling_point

 

[Scotius]

Yeah. "Boiling" doesn't mean "hot" up there. In one of my favourite books about mountaineering expeditions, there is an amusing fragment about one of climbers dead set on cooking pea soup - at 5000+ meters of altitude. He kept full pot with him for three days, reheating it at every camp and trying to make the soup edible. Peas of course remained rock-solid and refused to cooperate. Only after the hapless cook tossed the pot off the cliff, one of his science-savvy colleagues explained why his efforts were futile.

[Streetwind]

He should have brought a pressure cooker

[Gaarst]

Apart from being really cold and asphixiated, you should be fine on top of Mount Everest.

On the other hand, if you go over 19000m without protection, you are going to have some troubles: at that height, pressure is so low water boils at 37°C (Armstrong limit). Anyway, you'd probably be dead before reaching that point.

[PB666]

51 minutes ago, Gaarst said:

Apart from being really cold and asphixiated, you should be fine on top of Mount Everest.

On the other hand, if you go over 19000m without protection, you are going to have some troubles: at that height, pressure is so low water boils at 37°C (Armstrong limit). Anyway, you'd probably be dead before reaching that point.

The armstrong limit is an atmospher 1/19th that of MSL. if you consider that the p02 at sea level is around 0.3 ATM and at 1/19th you gave a pilot 100% O2, your pO2 is .05 ATM. The pilot has a more immediate problem, he has about half the 02 he might have standing on the top of mt Everest. How do you get the water to boil, you burner flames out. The other problem that he will find before that limit, the pH20 relatively increases versus p02, so a few thousand feet before reaching hat limit his moisture in the lung is creating a positive pressure preventing inhalation of O2, so in reality not to much higher than Everest you are reaching the suffocation limit. 

Life as it turns out is not that flexible, might explain why little booblings are not popping up in for group photos in our mars expeditions. Not only does a world have to have an atmosphere, but it has to have enough to keep the partial pressures of critcal gases high enough for life to exist. CO2 is not a critcal gas for anything, except late coming phototrophs, but waters liquid phase  is, and its not going to stay liquid long. 

Edited December 13, 2015 by PB666

[benzman]

When my wife and I were on holiday in the USA we stopped at Jacob Lake, Arizona and went into the roadhouse.  We are Australians, essentially Flatlanders, and didn't realise that we were about 8000' above sea level.  I innocently ordered poached eggs and was gently told that at that altitude it would take about half an hour to cook them!  I didn't make that mistake again.

 

[Shpaget]

Phase diagram says it all.

[PB666]

On December 13, 2015 at 2:40:55 PM, benzman said:

When my wife and I were on holiday in the USA we stopped at Jacob Lake, Arizona and went into the roadhouse.  We are Australians, essentially Flatlanders, and didn't realise that we were about 8000' above sea level.  I innocently ordered poached eggs and was gently told that at that altitude it would take about half an hour to cook them!  I didn't make that mistake again.

 

Just put them in the microwave, they are done when they explode, takes about 25. seconds. lol.

[1101]

On 13/12/2015, 20:40:55, benzman said:

When my wife and I were on holiday in the USA we stopped at Jacob Lake, Arizona and went into the roadhouse.  We are Australians, essentially Flatlanders, and didn't realise that we were about 8000' above sea level.  I innocently ordered poached eggs and was gently told that at that altitude it would take about half an hour to cook them!  I didn't make that mistake again.

 

Just looked it up in a book: 'Mountaineering; The Freedom of The Hills':   It states that for every 5 C drop in water boiling temperature, cooking time doubles.  It lists heights up to 7km, and says at that altitude time to cook something is about 13 times longer than at Sea level.

[Scotius]

At 7 km height no one does a lot of cooking. It's rather warming foodstuffs up from "solid and ice cold" to "edible". It is just one of many stresses human organism must deal with in highest mountains. There is a good reason why such altitudes are called "The Death Zone" by climbers. No matter how healthy and fit you are - once you climb too high, your body effectively starts dying.

[PB666]

The dying zone differs for different  people. Thier is the claim is that the sherpers have genes they inherited fron Neandertals that improve high altitude survivability. You could get a collection of genes and if you could have some who could set and survive with a lower body temperature you could go higher. There are also environmental things like optimal climbing diets, right cloths, load acclimization.

Humans are not that well adapted to extremes altitudes  and for good reason, if we look for instance at paleolithic bone carbon for the majority of african derived humans there has tended to be a higher than present marine carbon content. This is particularly true in Europe prior to the neolithic, there was a shift from neandertals than had lower marine carbon content to late paleolithic humans. This is for a good reason, if your an extreme generalist, you want to spend most or you time were your calories are.

This guy https://en.m.wikipedia.org/wiki/Wolverine apparently cross an alaskan moutain peak in the dead of winter simply because its a short-cut.  It digs into the snow during the coldest part of the year, not to hibernate but to procreate, resourced on the carrion of mammals that did not survive the winter. They probably developed a cold weather high altitude endurance because animals that were pushed up slopes and perished in winter would be a bounty during the thaw in winter. 

The limits are flexible, but there has to be a selective pressure to keep the rare mutations that appear from time to time in the breeding population.