Effects of Roshars Oxigen levels

[Shaukan-son-Hasweth he/him]

I know from Khriss-essay and WOBs in general that the Oxigen levels on Roshar are higher than "cosmere Standard".
She warns that it causes Fires on Roshar to be resond unusually.
From what I recall, even though spheres are more wide spread, people use fire quite normally in torches, cookfires etc.

But are there any instances within the Stormlight books that actually refrence or depict the effects of fire on Roshar. Or was this aspect of the worldbuilding only considered later?

[alder24]

1 hour ago, Shaukan-son-Hasweth said:

I know from Khriss-essay and WOBs in general that the Oxigen levels on Roshar are higher than "cosmere Standard".
She warns that it causes Fires on Roshar to be resond unusually.
From what I recall, even though spheres are more wide spread, people use fire quite normally in torches, cookfires etc.

But are there any instances within the Stormlight books that actually refrence or depict the effects of fire on Roshar. Or was this aspect of the worldbuilding only considered later?

I don't remember any. Yes there are fire pits and torches, but I don't recall any arson or wildfires. Keep in mind, most buildings on Roshar are made out of stone or crem, non-flammable material. Any wood structure would be instantly blown away by the first Highstorm. That's why you wouldn't see fires consuming villages or cities with one notable exception - Rathalas which was purposefully ignited by Dalinar with the aid of oil and contained many wooden structures, the flames were large and hot, oxygen definitely helped (which is not something that characters in-world would recognise as for them this is normal, they can't compare it to standart levels of oxygen on different planets). OB ch 76:

Quote

The soldiers unplugged barrels of oil, then began dropping them down, soaking the upper levels of the city. Flaming brands followed—starting struts and walkways on fire. The very foundations of this city were flammable.
[...]
He watched as the fires spread, flamespren rising in them, seeming larger and more … angry than normal.
[...]
The Rift behind him was becoming a pit of darkness and fire. Dalinar retreated up the ramp to the stones above. Archers lit the final walkways and ramps behind him.
[...]
Some elites ran to try to do as Dalinar said, but they shied away from the Rift—the heat rising from the burning city was incredible.
Dalinar roared, standing, pushing toward the flames. However, the fire was too intense.

The large oxygen level on Roshar also allows large crustaceans to exist there. That's another effect. 

[Treamayne]

1 hour ago, Shaukan-son-Hasweth said:

But are there any instances within the Stormlight books that actually refrence or depict the effects of fire on Roshar.

29 minutes ago, alder24 said:

Any wood structure would be instantly blown away by the first Highstorm. That's why you wouldn't see fires consuming villages or cities with one notable exception - Rathalas which was purposefully ignited by Dalinar with the aid of oil and contained many wooden structures, the flames were large and hot, oxygen definitely helped

There are also subtle indication in some Jasnah scenes, such as (OB Ch 120)

Spoiler

Jasnah raised an absent hand without looking, forming a wall of black pitch. A Fused crashed through it, and Jasnah Soulcast a flick of fire, sending the thing screaming and flailing, burning with a terrible smoke.

Jasnah Soulcast the rest of the pitch on the wall to smoke, then continued forward.

Many don't realize it, but you can douse a lit match in diesel fuel and it will not catch fire. Pitch is actually a resin, and used in ancient warfare (like burning pitch, greek fire and naptha oil) needed additives to make it more flammable. Pitch is not easy to ignite - it was used that way because it burns long and hot. So, examples like this, where things are shown to ignite far more easily than they should are the best examples I can find for the effects of teh high oxygen environment on fire. 

[Quantus he/him]

I tend to think it will mostly only be relevant (or noticed) with Worldhoppers that have some alternate reference frame.  Everything else would hide behind the local familiarity; they wont really notice fire being different any more than they'll notice the low gravity or their above average heights or their lack of "normal" illness.  

1 hour ago, Treamayne said:

Many don't realize it, but you can douse a lit match in diesel fuel and it will not catch fire. Pitch is actually a resin, and used in ancient warfare (like burning pitch, greek fire and naptha oil) needed additives to make it more flammable. Pitch is not easy to ignite - it was used that way because it burns long and hot. So, examples like this, where things are shown to ignite far more easily than they should are the best examples I can find for the effects of teh high oxygen environment on fire. 

Very true and very likely. Flammability is a sliding scale based on O2 concentrations and atmospheric pressures. In a pure O2 environment nearly any hydrocarbon will burn pretty easily.

The devil's advocate statement is that rosharan "pitch" is likely another generic term.   Theirs is unlikely to be any of the petrochemical versions used historically, they're likely to be something organic closer to whale oil or even some sort of flammable squid-ink (given the ocean theme for a lot of their ecology).  If her "spark" was hot enough it might vaporize enough starter substance to get sustained combustion going.  

[Treamayne]

12 minutes ago, Quantus said:

rosharan "pitch" is likely another generic term.   Theirs is unlikely to be any of the petrochemical versions used historically, they're likely to be something organic closer to whale oil or even some sort of flammable squid-ink (given the ocean theme for a lot of their ecology).  If her "spark" was hot enough it might vaporize enough starter substance to get sustained combustion going.  

Entirely possible. But also consider that, from a Soulcasting perspective, we normally hear Jasnah use one of the ten essences, and she has used Oil before - but specifically used Pitch in this case (and made sure to Soulcast the remainder back to smoke). So, whether it is a resin-derived similar substance, or just something close enough to use the same name, I feel the implication is that it would not catch fire as quickly on a "Cosmere standard" world but works on Roshar well because of the environment. 

Not that she would have a way to know that - but I feel it is the inference we are meant to draw as readers. 

[Quantus he/him]

7 minutes ago, Treamayne said:

Entirely possible. But also consider that, from a Soulcasting perspective, we normally hear Jasnah use one of the ten essences, and she has used Oil before - but specifically used Pitch in this case (and made sure to Soulcast the remainder back to smoke). So, whether it is a resin-derived similar substance, or just something close enough to use the same name, I feel the implication is that it would not catch fire as quickly on a "Cosmere standard" world but works on Roshar well because of the environment. 

Not that she would have a way to know that - but I feel it is the inference we are meant to draw as readers. 

Agreed, just by the science of oxygen anything will burn less effectively off Roshar than on it.  Whether it only burns on roshar might be a different question, i guess

 

[Shaukan-son-Hasweth he/him]

Thank you guys!

Rathalas was one of the instances, that I had in mind as well.

And the burning pitch is an interesting one. I don't think Jasnah could have cast Petroleum ore something. Since it likely isn't someting she understands that well, since it's not in wide use on Roshar.

[Duxredux he/him]

Depending on how you interpret the whole "does the wind bring the spren or the spren bring the wind" thing, fire is unusual on Roshar due to the nature of flamespren. In WoK Interlude I-8, you have the two ardents who discover that measuring a flame spren's size and recording it locks it into a fixed size. I looked it up to see if the measurements that they call out are indicative of anything, but it's logs in a hearth, not something easily comparable like a candle flame. Incidentally, the measurements were 3 7/10 inches, 2 8/10 inches, and 2 3/10 inches which indicates that they could be measured to the nearest tenth by an elderly ardent adjusting a set of calipers, which may say something about the stability of the flames.

It's not related to fire, but a few people have noted that 10 heart beats seems like it takes an abnormally long time with a lot of stuff happening when Shardbearers summon dead Blades. Roshar's reduction in gravity and increase of oxygen in the atmosphere that supports greatshells also changes the heart rates of Rosharans. A decrease in gravity and an increase in oxygen levels have both shown to decrease heart rate. This means that summoning time for dead Blades is longer than would be expected from a typical heart rate seen on earth of anywhere from 40 to 200 bpm depending on athleticism and activity which corresponds to 15 to 3 seconds for 10 heart beats respectively.

Another example may be at how constantly Kaladin works at maintaining his equipment and teaching his command to do the same. Between Highstorms and the Weeping providing high humidity and water content and a highly oxygenated atmosphere, metals will rust much faster than on earth. On returning to Hearthstone, he finds fault with one of the guards because of the rust on his helmet going so far as to think "That rusted cap was a disgrace." 

Basically the higher oxygen level will effect everything that chemically relates to atmospheric oxygen, combustion, metabolism, or oxidization. By increasing the oxygen in the atmosphere, every chemical reaction that is reliant on atmospheric oxygen will react more quickly as more oxygen is available for the reaction. 

 

23 hours ago, Treamayne said:

Many don't realize it, but you can douse a lit match in diesel fuel and it will not catch fire. Pitch is actually a resin, and used in ancient warfare (like burning pitch, greek fire and naptha oil) needed additives to make it more flammable. Pitch is not easy to ignite - it was used that way because it burns long and hot. So, examples like this, where things are shown to ignite far more easily than they should are the best examples I can find for the effects of teh high oxygen environment on fire. 

snip to another post

Entirely possible. But also consider that, from a Soulcasting perspective, we normally hear Jasnah use one of the ten essences, and she has used Oil before - but specifically used Pitch in this case (and made sure to Soulcast the remainder back to smoke). So, whether it is a resin-derived similar substance, or just something close enough to use the same name, I feel the implication is that it would not catch fire as quickly on a "Cosmere standard" world but works on Roshar well because of the environment. 

Yup, though I think the distinctions here really boil down to the state of the flammable matter. Yes, the specific chemicals involved in the combustion make a difference, but the state of the matter makes a huge difference. Flammable gasses quickly mix with the atmospheric oxygen allowing the combustion reaction to happen faster. This means that it burns fast and hot. Flammable liquids can totally douse a fire so long as it is depriving the fire of oxygen, which is why vehicles very carefully control the air to fuel ratio to ensure the proper stochiometric balance to optimize combustion. As a side note, imbalances in a car's air to fuel ratio will either leave unspent fuel which is a pollutant, or the oxygen will not all fully react leaving some carbon monoxide with the rest of the carbon dioxide. Both results are pretty bad to breathe. In this case, a puddle sitting on the floor will burn slower and longer than a gas because the liquid state restricts the rate that the combustion occurs, though the liquid probably will spread, bubble, or evaporate which will increase surface area and so get a higher oxygen to fuel ratio. Get to solid fuels and it takes even longer to burn because of the density of the fuel as well as the limited surface area restricting the rate of combustion which also allows it to thoroughly heat up other objects as it burns. If you take a solid fuel and increase the surface area, it becomes easier to burn (log vs sawdust) and is the reason why grain mills and silos need to very carefully maintained and cleaned so they don't explode (https://en.wikipedia.org/wiki/Tradeston_Flour_Mills_explosion). Mythbusters could probably test how hard it is to set a human sized and shaped person dunked in pitch on fire, but I'm not sure who else would do that safely.

5 hours ago, Shaukan-son-Hasweth said:

And the burning pitch is an interesting one. I don't think Jasnah could have cast Petroleum ore something. Since it likely isn't someting she understands that well, since it's not in wide use on Roshar.

In this case I assume she used pitch instead of a liquid fuel because she wanted to cover only the Fused in something flammable, not dump a wall's worth of oil on everything around her. Pitch is a good sticky, stable, flammable substance and not one that the Fused would just bounce off of or would splash down once formed.

 

21 hours ago, Quantus said:

Agreed, just by the science of oxygen anything will burn less effectively off Roshar than on it.  Whether it only burns on roshar might be a different question, i guess

You can test it, you just need to know the concentration of oxygen on Roshar and create an environment on Earth that matches it. Don't blow yourself up.

[Quantus he/him]

1 minute ago, Duxredux said:

You can test it, you just need to know the concentration of oxygen on Roshar and create an environment on Earth that matches it. Don't blow yourself up.

I'm all out of Rosharan "Pitch", but grab some next time you worldhop over there and we can run the experiment.