Nitrogen-breathing aliens

[Geonee]

I wanted to flesh out an alien evolved on an exotic Nitrogen atmosphere world which colonized a corrosive atmosphere world. The idea is, for them it is just a "tainted atmosphere". I need some help with this, my chemistry is all but forgotten.

1) A Nitrogen Atmosphere is classified as Exotic. However, a Nitrogen-Oxygen atmosphere can range from breathable (earth) to corrosive.

From the CT supplement "Exotic Atmospheres":

If nitrogen and oxygen are present in an atmosphere in certain combinations, the atmosphere becomes somewhat more hostile. Nitric acid (HNO3) can form under certain conditions, as can other interesting compounds which can be irritants in low concentrations, or can make the atmosphere corrosive in higher doses.

Hence I was thinking of having the homeworld have a nitrogen atmosphere, and the colony an oxygen "taint" turning it corrosive. Does anybody know what the certain combinations of oxygen and nitrogen and the certain conditions have to be to yield such an atmosphere? Nitric acid is liquid at normal temperatures, so we get oceans of the stuff. But what are the higher doses of the other interesting compounds which make the atmosphere corrosive? I am guessing those compounds are nitrogen oxides, which are deadly at extremely low concentrations. But, does "corrosive" refer to that, or to the atmosphere "eating" your skin?

2) I was reading Rob. O'Connor's Xenobiology stuff at Freelance Traveller. Aliens in a nitrogen atmosphere could make use of a "breathing" reaction inhaling Nitrogen and exhaling either ammonia or urea, with vegetal life using the inverse reaction (as photosynthesis). However, that should mean at least a small but significant amount of free ammonia in the atmosphere, I guess (is this true? We exhale CO2 and plants use it, but there is not much in our atmosphere). However, again from exotic atmospheres:

Atmospheres containing ammonia will have to be extremely mild to classify as exotic rather than corrosive, for in any kind of concentration ammonia will cause serious damage to exposed skin

Actually, ammonia is life-threatening in concentrations in excess of 500 parts per million, which is just 0.05%... close to nothing. Does this mean that a nitrogen-breathing alien (who would exhale ammonia) would quickly turn an exotic atmosphere into corrosive?

The alternative might be having it exhale urea (NH2-CO-NH2), which seems to be solid at standard temperatures... colorful, isn't it?

3) In the colony world, I was thinking of having local life use another "breathing" reaction, which inhales ammonia and turns it into (liquid) nitric acid, with vegetals using the opposite reaction. Of course, that means the colony world does have ammonia (generated by plants) in the atmosphere apart from the oxygen "taint". Is there something wrong with the picture?

 

[theSea]

Carlos--

Okay, I'm no xenologist either and my chemistry is a little rough but I'll bring what I can to the table.

Originally posted by Carlos:
1) A Nitrogen Atmosphere is classified as Exotic. However, a Nitrogen-Oxygen atmosphere can range from breathable (earth) to corrosive.

Keep in mind that it is the *oxygen* that is corrosive at high concentrations. Also as the O2 concentration goes up so does the likelyhood of things burning (e.g. the Apollo 1 fire).

Keep in mind that O2 is reactive enough that high concentrations will not be stable over geologic time without constant replenishment.

Hence I was thinking of having the homeworld have a nitrogen atmosphere, and the colony an oxygen "taint" turning it corrosive. Does anybody know what the certain combinations of oxygen and nitrogen and the certain conditions have to be to yield such an atmosphere? Nitric acid is liquid at normal temperatures, so we get oceans of the stuff. But what are the higher doses of the other interesting compounds which make the atmosphere corrosive? I am guessing those compounds are nitrogen oxides, which are deadly at extremely low concentrations. But, does "corrosive" refer to that, or to the atmosphere "eating" your skin?

I think this refers to the corrosive (oxidizing) nature of the O2 rather than the acid byproducts which are not likely to remain stable over geologic time..

2) I was reading Rob. O'Connor's Xenobiology stuff at Freelance Traveller. Aliens in a nitrogen atmosphere could make use of a "breathing" reaction inhaling Nitrogen and exhaling either ammonia or urea, with vegetal life using the inverse reaction (as photosynthesis). However, that should mean at least a small but significant amount of free ammonia in the atmosphere, I guess (is this true? We exhale CO2 and plants use it, but there is not much in our atmosphere). However, again from exotic atmospheres:

</font><blockquote>quote:</font><hr />Atmospheres containing ammonia will have to be extremely mild to classify as exotic rather than corrosive, for in any kind of concentration ammonia will cause serious damage to exposed skin

Actually, ammonia is life-threatening in concentrations in excess of 500 parts per million, which is just 0.05%... close to nothing. Does this mean that a nitrogen-breathing alien (who would exhale ammonia) would quickly turn an exotic atmosphere into corrosive?
</font>[/QUOTE]The levels of Ammonia that are toxic to terrestrial lifeforms are probably signifigantly lower that Ammonia levels required to render an atmosphere corrosive.... Levels around 0.05% would be either tainted or exotic with corrosive somewhat further up the continuium.

The alternative might be having it exhale urea (NH2-CO-NH2), which seems to be solid at standard temperatures... colorful, isn't it?

it could be in suspension... you excrete urea all the time

3) In the colony world, I was thinking of having local life use another "breathing" reaction, which inhales ammonia and turns it into (liquid) nitric acid, with vegetals using the opposite reaction. Of course, that means the colony world does have ammonia (generated by plants) in the atmosphere apart from the oxygen "taint". Is there something wrong with the picture?

The question would be "what's generating the oxygen?" The only reason there's oxygen in the atmosphere on Earth is that it is constantly replenished by photosynthesis (ask the first generation of anerobic life-forms how they felt about the chlorophyl revolution).. otherwise it would combine (oxidise) with other materials and eventuially dissapear.

Anyways my cr0.02 YMMV

 

[kafka47]

Did not the Giants Trilogy by James P. Hogan have a group of Nitrogen breathers as their central alien? But, I am not sure that Nitrogen is the best candidate, would not Methane be better, as it combines well with carbon and is much more abundant in the universe.

 

[Geonee]

Originally posted by kafka47:
Did not the Giants Trilogy by James P. Hogan have a group of Nitrogen breathers as their central alien? But, I am not sure that Nitrogen is the best candidate, would not Methane be better, as it combines well with carbon and is much more abundant in the universe.

Thanks for the Hogan hint. Methane requires large worlds with way-too-cold climates, making for less-playable alines, at least IMHO.

 

[Geonee]

Originally posted by theSea:
Keep in mind that O2 is reactive enough that high concentrations will not be stable over geologic time without constant replenishment.
SNIP
The question would be "what's generating the oxygen?" The only reason there's oxygen in the atmosphere on Earth is that it is constantly replenished by photosynthesis (ask the first generation of anerobic life-forms how they felt about the chlorophyl revolution).. otherwise it would combine (oxidise) with other materials and eventuially dissapear.

Indeed. I think I'll go for a homeworld with Exotic=Nitrogen atmosphere, and acolony with Corrosive=Nitrogen+Ammonia atmosphere. In the homeworld, aliens inhale nitrogen and secrete solid urea (vice versa for plants), in the colony native life inhales ammonia and excretes liquid nitric acid (vice versa for plants). Native life in the colony is unedible to the sophonts.

Originally posted by theSea:
</font><blockquote>quote:</font><hr />Originally posted by Carlos:
The alternative might be having it exhale urea (NH2-CO-NH2), which seems to be solid at standard temperatures... colorful, isn't it?

it could be in suspension... you excrete urea all the time </font>[/QUOTE]So these aliens inhale, but do not exhale? And have to hit the men's room every 30 minutes?

Many thanks for your comments.

 

[Rodina]

Florine and Chlorine are also good candidates for reactive elements as a basis for metabolism. Of course, Florine is so reactive, it usually binds itself up.

But the Nitrogen thing is cool, especially if you've got an obvious, lower energy chemical to excrete once you are done with it.

 

[Liam Devlin]

These aliens would be your Keumi from Keum-massilia, aye? (IMTU page reference). Cool. Keep me posted!

 

[Geonee]

Originally posted by Liam Devlin:
These aliens would be your Keumi from Keum-massilia, aye? (IMTU page reference). Cool. Keep me posted!

Yes sir, they are. You got me <g>. The "colony world" is Emsingale.

 

[Geonee]

First, preliminary try at the Keumi. Comments welcome. A map of the area referred below can be found here. (I am developing this area, see the MT board).

Keumi worlds: The Keumi are a minor alien race of nitrogen-breathers native to Keum (0815 Keum/Massilia, A6A198A-E), Massilia’s sector capital. Keumi minorities and travelers can be found throughout Massilia, Zarushagaar, and Delphi sectors, but there are only 8 worlds inhabited mainly by Keumi, all of them in Keum and Vaait subsectors in Massilia.

Biology: Keumi are tall (average 2.5 m), slender, bipedal humanoids whose metabolism makes use of nitrogen (inhaled from the atmosphere) and produces solid urea as a breakdown product (which is kept in liquid suspension, as in humans, but must be evacuated more frequently). The most non-humanoid elements of their physiology are their triple-articulation arms and legs (which give them a very particular and almost Vargr-like walking stance) and their face, which has two large eyes and a mouth but no nose. Nitrogen is inhaled by two branchia-like organs on the sides of the head, located after two hearing organs consisting of a maze of hair-like appendices. Excess nitrogen can be exhaled through the mouth. Their sense of smell is located inside the mouth, and they do not distinguish between smell and taste (the closest translation of ‘smelling’ in their languages actually means ‘tasting the air’)
Free oxygen is toxic and even corrosive for Keumi, depending on concentration. In a standard nitrogen-oxygen atmosphere, a Keumi must wear an isolation suit, but needs not carry “air” tanks, as a number of filters have been developed in order to allow them to consume the atmosphere’s nitrogen. Keum produces TL-14 skintight, self-sealing suits with incorporated filters which allow Keumi to walk normally on a human world’s surface.
Keumi are slightly weaker and slightly more dextrous than humans on average. However, in a nitrogen or standard atmosphere (hence with more than 70% of nitrogen), they are capable of regulating their nitrogen intake to increase energy production over short periods of time (up to ten minutes), effectively receiving an “energy boost” which increases their strength and endurance above human levels. The first symptom that the boost effect has finished is an unstoppable need to evacuate the resulting urea.
In order to talk, Keumi must release nitrogen through their mouths, which forces them to increase the nitrogen intake. Hence, if they talk too quickly, they become agitated and suffer effects similar to an energy boost. Due to this effect, Keumi usually talk slowly, the expression “fast-talk” being close to aggressive behavior for them.
Keumi reproduce sexually, with three differentiated sexes: male, female, and bearer. The genetic material of males and females combines in a pre-zygote which must then be transferred to a bearer for development. External differences between males and females are minimal to outside observers, but bearers are significantly heavier and more resistant than other Keumi.

Society: Keumi are usually peaceful and inclined to abstract matters as philosophy and abstract math, and prefer to settle matters through discussion whenever possible. There are many philosophical schools among them, some even inspired by human schools. The three more extended schools are the fatalist Kareda (who defend the universe’s ultimate mechanicism and the unavoidable character of fate), the almost-stoic Vurega (who maintain every individual must constantly struggle for the benefit of society, ignoring personal consequences), and the Kantians (partially inspired by old terran philosophy, and interested above all in the almost self-centered understanding of reasoning procedures).
Keumi usually favor democratic or bureaucratic governments. However, they have a racial sense of unity which transforms their worlds in something as close to an interstellar state as can be under the Third Imperium. For example, the only prerequisite to serve in government positions in a Keumi world is to be a Keumi, and not to be a native of the world.

History: The Keumi were first contacted by Geonee traders before the First Imperium, who found them in the equivalent of stone age. By the time they were absorbed by the First Imperium, they had already advanced to a pre-stellar technology level, with the help of imported Geonee technology. As part of their development plans for the subsector, the Vilani established a colony of Keumi in mineral-rich Emsingale (0415 Keum, B8B4999-D), a world with a nitrogen atmosphere tainted with ammonia (making it corrosive for human standards), which thrived enormously in a few centuries and is still the second world in Keumi population nowadays.
In the last centuries of the Long Night, Keumi settled the nearby systems of Lenora (0914 Vaait, B7A4775-B) and Nonodaga (0915 Vaait, BAA9642-C), whose mainworlds also have exotic nitrogen atmospheres. Nowadays, Nonodaga is a democratic world, while Lenora is balkanized in two countries. The largest one (22 millions inhabitants), whose name translates as Lenora Republic, is again democratic. The smallest one (12 millions) is a dictatorial state called Karedaga, which is all but ostracized by the Keumi worlds.
More recently, under the Third Imperium, the Keumi have established colonies in vaccum worlds in systems near Keum. These are Mannai Nila (0716 Keum, B200542-D), Mancilla (0814 Keum, B100442-D), which was previously practically uninhabited; Stard (0916 Vaait, E10056A); and Naramorz Rock (1015 Vaait, B300567-D). All of these worlds were previously practically unihabited, except for Mannai Nila, which had a significant human population before the Third Imperium but had been gradually abandoned by original human colonists. Mannai Nila and Mancilla have already gained independence from the homeworld and established democratic systems. Stard and Naramorz are “colonial worlds” with a governing body appointed by authorities from Keum and the other Keumi worlds.

 

[Zutroi]

A little something to consider regarding Urea chemistry - dissolving urea in water is an endothermic reaction, it requires heat to do this and will therefore cool the vessel they're being combined in. If your aliens idi this in an organ behind the visual sensors (OK, eyes) they would possibly have a natural IR vision.

The only Terran creatures that see in IR are cold blooded, for the obvious reason that the creature's own body heat would interfere, but your guys now have a way to actively cool their retinas to below body temp!

 

[MrMorden]

I'm no chemist, first of all.

But Nitrogen is an inert element; doesn't this mean it's a very poor candidate (if not an impossible one) as a basis for metabolism? Reactivity (as with O2, Methane, Ammonia, etc.) is needed for something to happen, correct?

There are plenty of Nitrogen compounds that would work, but free N seems a longshot.

 

[TKalbfus]

I breath Nitrogen all the time, its no big deal. Nitrogen enters my lungs everytime I take a breath. Nitrogen is in my bloodstream. What is the big deal about breathing Nitogen?

 

[EvilDrGanymede]

Originally posted by Tom Kalbfus:
I breath Nitrogen all the time, its no big deal. Nitrogen enters my lungs everytime I take a breath. Nitrogen is in my bloodstream. What is the big deal about breathing Nitogen?

In our atmosphere, nitrogen is a buffer gas. Though that said IIRC some terrestrial lifeforms use it for something (don't plants 'fix' nitrogen as well as taking in CO2? Or is that bacteria?)

But for us, the N2 is there just to fill the space, so to speak. We don't use it for anything in our bodies, and it doesn't harm or benefit us otherwise (in current concentrations/pressures) - it's the oxygen in the air that we need as the 'energy source' for our metabolism, there just happens to be four times less of that in the air than nitrogen.

WHat people are talking about here is using nitrogen as the 'energy source', but since nitrogen is so unreactive it's kinda hard to get any energy out of it. Ammonia would be a more viable energy source for an alternate ecosystem, since that IS reactive.

 

[Granpafishy]

If it's any help, the game "Battle Lords of the 23rd Century" has metane breathers. The game site is http://www.ssdc.com/ It might help with intial designs.

 

[TKalbfus]

But for us, the N2 is there just to fill the space, so to speak. We don't use it for anything in our bodies, and it doesn't harm or benefit us otherwise (in current concentrations/pressures) - it's the oxygen in the air that we need as the 'energy source' for our metabolism, there just happens to be four times less of that in the air than nitrogen.

WHat people are talking about here is using nitrogen as the 'energy source', but since nitrogen is so unreactive it's kinda hard to get any energy out of it. Ammonia would be a more viable energy source for an alternate ecosystem, since that IS reactive.

Yet we still breath nitrogen. Deep down in submarines we also sometimes breath helium. I don't know how you make nitrogen do something it won't do. Nitrogen forms compounds that make good explosives.

 

[EvilDrGanymede]

Originally posted by Tom Kalbfus:
Yet we still breath nitrogen. Deep down in submarines we also sometimes breath helium.

We breathe nitrogen, but we don't use it. We have no natural external means of just taking in the oxygen, so we breathe the whole mix in and separate it out in the lungs. We do not use all the gases in the air.

I don't think subs use helium in their air mix, but deep divers do, because you have to pressurise the mix. Above a certain pressure, you get nitrogen narcosis (potentially fatal) so you have to replace that with helium, which lets you dive deeper (and would give you a squeaky voice), but you have to do more decompression stops if you're using that.

I don't know how you make nitrogen do something it won't do. Nitrogen forms compounds that make good explosives.

So? Ammonia might work as an 'active gas' because it's a reactive compound and you can get energy out of it that way. Nitrogen won't work on its own because it doesn't do that. I can't imagine a nitroglycerin based ecosystem, somehow...

 

[mike wightman]

Nitroglycerin is used to treat angina, so why not postulate a compound of this type being used by an aliens metabolism much as ADP and ATP are used by ours?
In a food chain a producer is needed that can somehow store energy in chemical form. On Earth that usually means green plants photosynthesising cabohydrates, an endothermic or energy trapping process. Respiration releases this stored energy.
So on this nitrogen atmosphere world the plant analogues don't produce oxygen as a waste product of their "photosynthesis", perhaps it's ammonia, water or methane, but they do produce some sort of nitrogen based compound that can be broken down exothermically to release energy in cells by some strange alien enzyme catalysed reaction, don't ask me how, this is alien biochemistry . Perhaps the lungs of these aliens contain "bacteria" which absorb nitrogen from the atmosphere to form compounds which react with the food molecules. They may even have nitric acid for blood

.

 

[Drakon]

Originally posted by Evil Dr Ganymede:

I don't think subs use helium in their air mix, but deep divers do, because you have to pressurise the mix.

We do not use helium on submarines. Some deep divers use it, as you say to prevent nitrogen narcosis, which can be fatal. Submarine air is just like normal air. We make our own oxygen, splitting it off from the hydrogen and dumping that hydrogen overboard. The nitrogen we do not have to make, because, as you say, we don't use it when breathing.

CO2 and hdyrogen gas onboard submarines are removed using scrubbers (for CO2) and burners (for hydrogen primarily, but it works for almost any hydrocarbon contaminant.) The air aboard is run through a special liquid, which sucks the CO2 out of the air, and, when heated, releases that CO2 back out. When you heat it in a special tank, you can then expel the CO2 overboard.

Burners essentially run the ship's air through a special catalyst, which is extremely hot. CO converts to CO2 to be cleaned by the scrubbers, H2 becomes water, drains to the bilge.

So while submarines may still smell of diesel exhaust and outhouses, the air is still the same stuff civilians breathe. It would be way too expensive to use helium, render the sub unable to ventilate on the surface or with a snorkle, and worst of all, make the officers sound silly while giving orders.

 

[EvilDrGanymede]

Originally posted by Drakon:
Submarine air is just like normal air. We make our own oxygen, splitting it off from the hydrogen and dumping that hydrogen overboard.

Oh... so that would explain where the hydrogen comes from in the movie 'Below'. For some odd reason I thought it had something to do with the batteries.

 

[GypsyComet]

Originally posted by Sigg Oddra:
Nitroglycerin is used to treat angina, so why not postulate a compound of this type being used by an aliens metabolism much as ADP and ATP are used by ours?

A world where the dead are self-immolating, and you don't dare step in the cow pies because your boots will explode a few hours later?