Can a human and an ammonia-based alien coexist?

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  • #1
HavNoFear
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Writing a sci-fi story, thinking of making the alien species ammonia-based. Obviously there are problems with that. On Earth, ammonia is a liquid under cryogenic temperatures. I think -28 degree Fahrenheit is its boiling point. Obviously, this is too cold for a human to survive for very long without some kind of really, really good thermal wear or some kind of environmental suit, both of which I was hoping to avoid.

The other option I have, which would allow ammonia to be a liquid at more normal, room temperatures, is to simply increase the atmospheric pressure of the planet they're on. However, my research says that ammonia's boiling point is at 70 degrees under 128.8 psia. Normal Earth air pressure at sea level is 14.7 psia.

So my two problems there is figuring out how many atmospheres a planet would need to have, to have a sea level pressure of 128.8 psia. I'm terrible at math, as you have probably figured out. THEN, what I need to figure out is if a human can even survive in 128.8 psia. It sounds a bit ... extreme.

Then again, I do know deep sea divers acclimate to much higher pressures, but they can only breathe properly if they change their oxygen mixture. Requiring my human character to have a supplementary breathing apparatus in this story is a possibility, but I still don't know if any of this is possible. Can you guys help me out?
 

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  • #2
phinds
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Why are you assuming that the ammonia would have to be pure? Is the Earth's atmosphere pure oxygen? Is household ammonia pure ammonia? Stuff to think about.
 
  • #3
HavNoFear
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Well in this case, i think for ammonia to work as a basis for biochemistry, it needs to be in a liquid form. I was going on pure only to simplify the problem, because I'm not terribly certain how ammonia reacts with various other chemicals. I know exposing ammonia to oxygen results in the creation of nitrous oxide and water, and I don't really know at what point such do these chemical mixtures result in a volitile reaction.

But if you want to offer any suggestions, I'm all ears.
 
  • #4
phinds
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Well in this case, i think for ammonia to work as a basis for biochemistry, it needs to be in a liquid form.
But why a PURE liquid form? I'm just throwing out ideas here. I have no real suggestions. Not my field at all.
 
  • #5
HavNoFear
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I'm not following you. Do you mean you think it ought to be part liquid or part gas?

I said, I was simplifying the chemical to focus on just one, and not several, because I'm trying to figure out if this is possible in its most basic form before I worry about combinations of chemicals and whether or not they'll degrade or explode
 
  • #6
Vanadium 50
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Ammonia is water soluble. Again, why pure ammonia?
 
  • #8
Vanadium 50
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Then it sounds like you have your answer, and it is "no, you can't".
 
  • #9
newjerseyrunner
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Writing a sci-fi story, thinking of making the alien species ammonia-based. Obviously there are problems with that. On Earth, ammonia is a liquid under cryogenic temperatures. I think -28 degree Fahrenheit is its boiling point. Obviously, this is too cold for a human to survive for very long without some kind of really, really good thermal wear or some kind of environmental suit, both of which I was hoping to avoid.

The other option I have, which would allow ammonia to be a liquid at more normal, room temperatures, is to simply increase the atmospheric pressure of the planet they're on. However, my research says that ammonia's boiling point is at 70 degrees under 128.8 psia. Normal Earth air pressure at sea level is 14.7 psia.

So my two problems there is figuring out how many atmospheres a planet would need to have, to have a sea level pressure of 128.8 psia. I'm terrible at math, as you have probably figured out. THEN, what I need to figure out is if a human can even survive in 128.8 psia. It sounds a bit ... extreme.

Then again, I do know deep sea divers acclimate to much higher pressures, but they can only breathe properly if they change their oxygen mixture. Requiring my human character to have a supplementary breathing apparatus in this story is a possibility, but I still don't know if any of this is possible. Can you guys help me out?
I have a suggestion, I'm also writing a space story where I wanted to not require space suits.

Does your universe have force fields? A portable force field emitter can create an invisible environment suit directly around the character. It would appear as though your characters were walking about hostile environments without any suits, but your characters will have complete control over their environments. I use the same technology in my crew's personal force fields as the ship's force fields.
 
  • #10
gjonesy
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Since its a science fiction story you can take some creative license here, make your alien anyway you chose. Maybe they are a hyper adaptive species and moister from the atmosphere allows them to adapt to a human friendly environment...maybe there is an adjustment period, but after that they can coexist.
 
  • #11
TheQuietOne
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Since its a science fiction story you can take some creative license here, make your alien anyway you chose. Maybe they are a hyper adaptive species and moister from the atmosphere allows them to adapt to a human friendly environment...maybe there is an adjustment period, but after that they can coexist.
make it any way you choose, my suggestion is make them a super intelligent species inwhich tey created a suite that keeps them at the right conditions.
whatever you want
 
  • #12
Lren Zvsm
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I have a suggestion, I'm also writing a space story where I wanted to not require space suits.

Does your universe have force fields? A portable force field emitter can create an invisible environment suit directly around the character. It would appear as though your characters were walking about hostile environments without any suits, but your characters will have complete control over their environments. I use the same technology in my crew's personal force fields as the ship's force fields.

I am reminded of the "life belts" used by the crew of the Enterprise on Star Trek: The Animated Series. They projected a personal force field that does what a space suit does.
 
  • #13
greswd
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@HavNoFear if we heated a human being to 100 degrees C and upped the atmospheric pressure, he'd still be pretty dead. so I think the aliens will need a suit.
 

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