Underground biosphere, what can be the possibilities?

[GTOM]

While the caverns of Earth isn't really lifeless, but as far as i know, only small beings can sustain themselves with the scarce food supply.
What can be the hardness level of putting big animals into the underground caverns of an alien biosphere?
I wondered about the plausibility of the following options :
Maybe their biosphere could rather rely on heat energy of underground thermal waters than light?
Maybe enough biomass could reach the underground from the surface the feed big fish and amphibians?
Maybe bacteria could convert heat energy to light to feed regular plants?
Should they feed on coal?

 

[Simon Bridge]

It's about as plausible as living under domes on the surface - you'd just need to make sure the creatures have what they need.

 

[GTOM]

Living under domes on the surface - that means an artifical biosphere, that has to be maintained by sapient beings.
The question is, could such an underground biosphere go on its own?

 

[Borek]

I don't see why you can't have some kind of underground ecosystem similar in principle to those surrounding hydrothermal vents.

When I say "in principle" I mean - volcanic emissions being a source of energy. Whole system would be not trivial, as the presence of unlimited water and high pressure near hydrothermal vents helps deal with high temperature and toxicity of volcanic gases, which would otherwise kill animals around.

 

[Ryan_m_b]

A obvious problem with underground systems is a food source. Unlike soil rock is pretty hard to break down, plant and fungi life would have a hard time settling in and without them animals wouldn't have much to eat in order to grow to large sizes.

 

[Enigman]

I would use geothermal energy dependent producers rather than plants and not more than three trophic levels, a plankton-like producer with a large population, a primary consumer and a secondary consumer (if scary monsters are really necessary).

 

[Ryan_m_b]

I would use geothermal energy dependent producers rather than plants and not more than three trophic levels, a plankton-like producer with a large population, a primary consumer and a secondary consumer (if scary monsters are really necessary).

My point was that might get you energy but what about biomass? Where is that going to come from?

 

[Borek]

Good point, I concentrated on the energy source, but that's not all.

OTOH, apparently whatever system is there it has to be in some contact with the outside (I mean: it didn't evolve completely underground, more like it was colonized from above). That means some slow inflow of biomass is possible. Assuming "biomass conservation" (whatever got down there, stays down there) such system can slowly grow.

I wonder what are the amounts of marine snow that reach the benthic zone.

 

[Enigman]

My point was that might get you energy but what about biomass? Where is that going to come from?

I would go with hand-wavium on that.

Or on further thought:

A class of plankton-like recyclers, along with the occasional visitor from outside the biosphere who would be eaten by the predators and the biomass 'assimilated' into the system. Its not a biosphere which would be likely to evolve though.

And on further googling:
http://en.wikipedia.org/wiki/Troglofauna

 

[GTOM]

Well I also thought about slow inflow, as well as some kind of underground planktons able to convert atmospheric (probably volcanic?) CO2 into biomass.
Another thought was coal (mineral oil?), if something could digest it, a coal mine could be converted to lots of biomass.

(It could have been artifically created at first, but it should stand on its own legs.)

 

[Ryan_m_b]

Well I also thought about slow inflow, as well as some kind of underground planktons able to convert atmospheric (probably volcanic?) CO2 into biomass.

CO2, water and a source of energy could get you carbohydrates sure but there are plenty of other nutrients needed that come from soil: nitrogen, potassium, phosphorous, calcium, sulphur, magnesium and a whole lot more. The lack of soil in a cave environment is going to be a big limiting factor, I can't think of a way off the top of my head for pedogenesis to occur in a cave.

Another thought was coal (mineral oil?), if something could digest it, a coal mine could be converted to lots of biomass.

(It could have been artifically created at first, but it should stand on its own legs.)

Activated charcoal is a form of edible coal used in medicine but I don't think it's nutritious at all. I'm not sure what the requirements would be for digesting coal but I have a suspicion it's unlikely to evolve. In addition coal just contains carbon, hydrogen, oxygen and sulphur so it only gets you one extra nutrient (the rest being present in air and water).

 

[GTOM]

I see the problems...

Hmm, i thought about a great deluge happened on that planet. (caused by tectonic, volcanic activity something like that. well that part might be even pure handwavium )

What if that washed lots of stuff into the caverns, filled them with hot water?
Then gradually water level dropped and left a thin soil made by planktons, coralls fed on thermal energy?

Or the caverns itself would only provide a relatively safe territory for the eggs of amphibians that go to feed to the hot underground lakes or see?
(In those hot sees there would be much bigger competition and risks for the eggs.)

Underwater life can go on without soil or sunlight.

 

[Enigman]

Some of these might help in getting the micro-nutrients and perhaps soil-formation:

A lithoautotroph is a microbe which derives energy from reduced compounds of mineral origin. They may also be referred to as chemolithoautotrophs, a type of lithotrophs, reflecting their autotrophic metabolic pathways. Lithoautotrophs are exclusively microbes; macrofauna do not possesses the capability to utilize mineral sources of energy. For lithoautotrophic bacteria, only inorganic molecules can be used as energy sources. Most lithoautotrophs belong to the domain Bacteria. The term "Lithotroph" is created from the terms 'lithos' (rock) and 'troph' (consumer); literally, it may be read "eaters of rock." Many lithoautotrophs are extremophiles, but this is not universally so.

Lithoautotrophs are extremely specific in using their energy source. Thus, despite the diversity in using inorganic molecules in order to obtain energy that lithoautotrophs exhibit as a group, one particular lithoautotroph would use only one type of inorganic molecules to get its energy.

Lithoautotrophs participate in many geological processes, such as the weathering of parent material (bedrock) to form soil, as well as biogeochemical cycling of sulfur, potassium, and other elements. They may be present in the deep terrestrial subsurface (they have been found well over 3 km below the surface of the planet), in soils, and in endolith communities. As they are responsible for the liberation of many crucial nutrients, and participate in the formation of soil, lithoautotrophs play a crucial role in the maintenance of life on Earth.
http://en.wikipedia.org/wiki/Lithoautotroph

 

[GTOM]

Now I am thinking about a short SF story, where machines took over Earth, and people live like rats in the vast underground network of metro tunnels, sewers, transit pipes, rad shelters, parking garages etc.
I thought the base of life would be hybrid (bio-machine) mushrooms, that feed on organic material and omnipresent electrosmog, radiowaves. Theese mushrooms feed rats, and provide other necessary material like nitroglicerin (against hunter robots), stuff that can be made to protective clothing, etc.
Those this idea has anything to do with reality? (I don't intend to be very hard...)

 

[Czcibor]

Now I am thinking about a short SF story, where machines took over Earth, and people live like rats in the vast underground network of metro tunnels, sewers, transit pipes, rad shelters, parking garages etc.
I thought the base of life would be hybrid (bio-machine) mushrooms, that feed on organic material and omnipresent electrosmog, radiowaves. Theese mushrooms feed rats, and provide other necessary material like nitroglicerin (against hunter robots), stuff that can be made to protective clothing, etc.
Those this idea has anything to do with reality? (I don't intend to be very hard...)

I think I watched some film with robots on top and humans deep below, that but with more acrobatics. ;)

I see 2 ideas:
1) the food chain gots big input of nutrients from outside:
-bat cave
-a river that goes underground

2) Humans keep a source of energy that allow to have undergound greenhouses, presumably nuclear or geothermal

 

[GTOM]

Hmm, an underground nuclear power plant run by humans would be too much. What can be the lifetime of a small nuclear battery, if they only use it for lighting, can it be safe?

About, the other... maybe due to global warming, the sea has flooded lower level tunnels, so humans have the upper level tunnels, and fish below?

 

[Almeisan]

Caverns are lifeless? Thought there are bacteria 3 km deep into the rockbed like about everywhere on earth.

Problem is, you can't just shallow litres of rock and filter out the microbes like a whale can do with plankton in the ocean.
Density of biomass will likely be very low.

 

[Czcibor]

Hmm, an underground nuclear power plant run by humans would be too much. What can be the lifetime of a small nuclear battery, if they only use it for lighting, can it be safe?

About, the other... maybe due to global warming, the sea has flooded lower level tunnels, so humans have the upper level tunnels, and fish below?

Nuclear reactors are too expensive? I understand that taking a small one from a submarine is also out? Then what about:
"Most RTGs use 238Pu, which decays with a half-life of 87.7"
https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator

One more idea: keep this underground stream, but also have a possibility to generate some amount of hydropower?

Anyway why not using energy from geothermals?

This RTG could be man portable - it may be a local version of holy grail.

You do not need necessary global warming. You could also use land reclaim in Holand style which is no longer maintained so sea returned.Metropolis flooded by sea, energy generated by tidal power plant and quest for finding a RTG? ;)

 

[GTOM]

A geothermal or nuclear power plant requires lots of infrastructure, and i think the survivors don't have that. (I also don't think they built a big city over a hotspot of Earth.)
RTG is a good idea (I like that holy grail stuff :) ) but wouldn't the radiation poison the people around it?
Tidal power, i think it is also right. :)

 

[Czcibor]

A geothermal or nuclear power plant requires lots of infrastructure, and i think the survivors don't have that. (I also don't think they built a big city over a hotspot of Earth.)
RTG is a good idea (I like that holy grail stuff :) ) but wouldn't the radiation poison the people around it?
Tidal power, i think it is also right. :)

Pu238 produces mostly alpha radiation, which is very easy to shield (dangerous only direct consumption / inhaling). However, if you use something more improvised, then theoretically heavy lead shielding should protect you... assuming that is not broken...

You want a damaged one which would be both blessing and a curse? :D

Tides would rather require a moon. (but there are a few other possibilities if you need it)Anyway, for my own story I toyed with a different idea, hard SF, maybe useful. Very long day night cycle (quite common on moons) or tilted planet. Then you have scorching heat wave during day (+50C?), freezing during nigh (-50C?). Aquatic life barely notices that, while humans can go out only during part of morning and a while after sunset. For most of the time they have hide underground. Continents are uninhabitable, while sea coast / islands are only very bad.

What can be the lifetime of a small nuclear battery, if they only use it for lighting, can it be safe?

Keep in mind that it produces energy continuously and it is irrelevant, whether it is actually use it or not.

 

[GTOM]

Ok, thanks for your help. :)

I planned the following plot : the hero find a wounded girl, they live on fish, mushrooms and rats till they manage to reach a hive, that has some "energy source" (RTG or whatever) they have a greenhouse.
The girl starts to speak about a Destiny. Then the robots attack the hive, they manage to escape with the help of nitro bottles, a pickaxe and a rifle.
Eventually they reach the promised place : a renegade AI decided that the AI society became decadent, they need the humans, it experimented with some humans and created some cyborgs, and a nano-virus (self-replicating nanobots). Since the virus could destroy all AIs including it, it hesitated the employ it (or it wanted to create enough cyborgs to upload itself into cyborg bodies that protected from the virus), and others destroyed that AI.
Generations later, one cyborg (the girl) gets out of hibernation (someone finds it, and opens it). Then with the help of the uploaded data they reach the hidden underground facility, and release the virus.

Is that plan total nonsense or sounds a little bit reasonable?

 

[Czcibor]

Ok, thanks for your help. :)

I planned the following plot : the hero find a wounded girl, they live on fish, mushrooms and rats till they manage to reach a hive

There are some reasons why there is a tiny limited number of survivors? (why they evaded attacks so far?)

that has some "energy source" (RTG or whatever) they have a greenhouse.

Who maintains that in workable state?

The girl starts to speak about a Destiny. Then the robots attack the hive, they manage to escape with the help of nitro bottles, a pickaxe and a rifle.

No EMP?

Eventually they reach the promised place : a renegade AI decided that the AI society became decadent, they need the humans, it experimented with some humans and created some cyborgs, and a nano-virus (self-replicating nanobots). Since the virus could destroy all AIs including it, it hesitated the employ it (or it wanted to create enough cyborgs to upload itself into cyborg bodies that protected from the virus), and others destroyed that AI.
Generations later, one cyborg (the girl) gets out of hibernation (someone finds it, and opens it). Then with the help of the uploaded data they reach the hidden underground facility, and release the virus.

Is that plan total nonsense or sounds a little bit reasonable?

How the hell a nanobots distinguish between cyborg and robot? Shouldn't they start "chewing" plastic anyway? And in case of cyborg just leave the brain (without life support) behind?

Why not using computer virus? To wipe most and cause damage to vital infrastructure, which would cause robot civilization collapse?

 

[GTOM]

Limited number of survivors : the AIs don't pay too much attention to hunt the remaining humans.

EMP would require high technology. Maintaining that energy source... well Voyager is working since almost 40 years.

Cyborg : with human body and a hybrid brain, that the virus don't recognize. I think the nano stuff is needed so switching simply to standalone mode isn't enough.

 

[Czcibor]

Limited number of survivors : the AIs don't pay too much attention to hunt the remaining humans.

Makes sense

EMP would require high technology. Maintaining that energy source... well Voyager is working since almost 40 years.

We have a different definition of high tech:
https://en.wikipedia.org/wiki/Explosively_pumped_flux_compression_generator

Cyborg : with human body and a hybrid brain, that the virus don't recognize. I think the nano stuff is needed so switching simply to standalone mode isn't enough.

The virus attack only the electronic brain? It is not in any casing?

 

[GTOM]

Okay, maybe some EMP grenade can be okay, but it isn't epic to solve everything with that, and they have a limited capacity.

Even if the processor is in some case, it still needs ports of electrically conductive material to outside. The cyborg brain can be fully wrapped in living organic material the nano stuff don't digest.

Or maybe it is better, that AIs became totally addicted to cloud computing, and one rather develops something entirely different to be able to operate standalone again?

 

[Czcibor]

Okay, maybe some EMP grenade can be okay, but it isn't epic to solve everything with that, and they have a limited capacity.

I'm not saying that it is necessary, however if the hero has some technical skill and raw material, then its one of more tempting weapons. Of course in real world there are also Farraday's cages as way of defending...

Even if the processor is in some case, it still needs ports of electrically conductive material to outside. The cyborg brain can be fully wrapped in living organic material the nano stuff don't digest.

So you don't need a brain, you need an organic enough skin / tissue.

Or maybe it is better, that AIs became totally addicted to cloud computing, and one rather develops something entirely different to be able to operate standalone again?

There are plenty of potential weak points:
-manufacturing facility (it is not so trivia to replace such high tech factory)
-mentioned cloud servers (good idea, data processing may be a key asset)
-energy source
-rare Earth source
-maintenance system
-governance system

Each of them targeted separately may be survivable. But what if a few targets were destroyed / very severely damaged in sudden strike... even then it may be less a decisive victory and more informing robots, then the setting become post apocalyptic also for them.

I have one more malicious idea - the main character may be clearly transhuman, according to his parents specification designed to be a tough guy... It would bring extra twist to human vs. robots.

 

[GTOM]

EMP vs Faraday cage, I read on wiki that high altitude nuclear blast had an effective range of 80km against satellites, and they turn off sat computers in times of solar storms.
Well EMP is only a small part of a nuclear blast, and it is undirected, but i guess explosive EMP don't have such good directivity neither... I guess those EMP grenades will has a rather short range.

Hmm, I see two options.
A : the nanobots drill through Faraday cages and create an EMP that erase all RAM, but the cyborg brain can fully restore itself from bio-RAM and ROM.
B : it took a long time till a regular computer virus could infect the majority of cloud computing hubs, it only needs a signal to launch. Anyway the renegade AI wanted to create a different kind of architecture, since the virus will be so devastating for AIs, and anyway, don't destroy unless create something new.

Some AI can switch to standalone in time, but still, with so much infrastructure damaged, the cyborg can take over robots and facilities, they will suffer.

Trans or posthumanism, i think everyone will be more or less different than present day average people, for example they learned echolocation (some blind people can learn it)
But if someone has superior abilities, what can be realistic a bit?
There was a series Alphas (http://www.imdb.com/title/tt1183865/), the hero team's abilities were a little bit believable, other one's abilities were total magical.

 

[Czcibor]

EMP vs Faraday cage, I read on wiki that high altitude nuclear blast had an effective range of 80km against satellites, and they turn off sat computers in times of solar storms.
Well EMP is only a small part of a nuclear blast, and it is undirected, but i guess explosive EMP don't have such good directivity neither... I guess those EMP grenades will has a rather short range.

Sure, its a nice weapon but no overkill. What about escaping the hideout and leave a time EMP bomb behind?

Hmm, I see two options.
A : the nanobots drill through Faraday cages and create an EMP that erase all RAM, but the cyborg brain can fully restore itself from bio-RAM and ROM.
B : it took a long time till a regular computer virus could infect the majority of cloud computing hubs, it only needs a signal to launch. Anyway the renegade AI wanted to create a different kind of architecture, since the virus will be so devastating for AIs, and anyway, don't destroy unless create something new.

I'd suggest B. Anyway, not only infection time but also writing time. Stuxnet was complicated enough to require a huge team of coders.

Putting a backdoor in firmware? And let enemy produce it?

Some AI can switch to standalone in time, but still, with so much infrastructure damaged, the cyborg can take over robots and facilities, they will suffer.

Anyway, why cyborgs and not more biodroids? I mean there could be an interesting war of attrition. Whole planet in ruins, but biodroids can reproduce everywhere, while robots require whole industrial system to produce new one...

Trans or posthumanism, i think everyone will be more or less different than present day average people, for example they learned echolocation (some blind people can learn it)
But if someone has superior abilities, what can be realistic a bit?
There was a series Alphas (http://www.imdb.com/title/tt1183865/), the hero team's abilities were a little bit believable, other one's abilities were total magical.

There are plenty of genetically realistic stuff that a transhuman could have. Echolocation is good. Generally the senses can be realistically tuned up. Especially... smell (yes, we're mediocre at it :D) .
Concerning sight:
http://scienceblogs.com/principles/2009/06/23/the-limits-of-elven-vision/
:D
Regeneration. Some animals can do it. In conjuction with some ability to constrict blood vessels, you may get a guy who is tough to kill.
Metabolism. Our mitochondria are inferior to birds. Moreover, there is one more extra here... we evolved under malnourishment conditions. Think about being that is optimized for burning 10 000 calories per day...
Spider silk... it beats kevlar. Nice component for skin, bones, joints...

 

[GTOM]

Sure, its a nice weapon but no overkill. What about escaping the hideout and leave a time EMP bomb behind?

Good.

I'd suggest B. Anyway, not only infection time but also writing time. Stuxnet was complicated enough to require a huge team of coders.

Writing time, the renegade AI had to write the virus before it was destroyed by others (i don't want it to guide directly my heroes)

Putting a backdoor in firmware? And let enemy produce it?

I don't fully understand that.

Anyway, why cyborgs and not more biodroids? I mean there could be an interesting war of attrition. Whole planet in ruins, but biodroids can reproduce everywhere, while robots require whole industrial system to produce new one...

What is the difference between biodroids and gene-engineered humans? A cyborg seems to me a nice alloy of human and AI, that it wanted.

There are plenty of genetically realistic stuff that a transhuman could have. Echolocation is good. Generally the senses can be realistically tuned up. Especially... smell (yes, we're mediocre at it :D) .
Concerning sight:
http://scienceblogs.com/principles/2009/06/23/the-limits-of-elven-vision/
:D
Regeneration. Some animals can do it. In conjuction with some ability to constrict blood vessels, you may get a guy who is tough to kill.
Metabolism. Our mitochondria are inferior to birds. Moreover, there is one more extra here... we evolved under malnourishment conditions. Think about being that is optimized for burning 10 000 calories per day...
Spider silk... it beats kevlar. Nice component for skin, bones, joints...

Hmm i think they won't be well fed in the sewers neither. I like the regeneration part the best, although i don't know how it could be inserted into a developed lifeform?
Another important part would be resist infections and drink polluted water. (They can destillate it, but anyway it is a good ability.)

 

[DaveC426913]

Unless your underground caverns are truly vast - like the size of whole countries** - you're going to have a problem with macro fauna.

**(how will a cavern the size of a country not collapse? Held up by stalactites? Nope. The stalactites would have had to form within an existing giant cavern - which would collapse before stalactites could form. Maybe a huge network of smaller caverns...)Historically, when populations of macro-fauna (horse, deer, etc) on oceanic islands have been isolated, what has happened is the fauna have evolved to a much smaller size (like two feet tall) to match the available food supply. (Because you still need a big population, or the species is not genetically robust).

Your situation will be even worse. On oceanic islands, the food and nutrient source is not a closed system, since there will always be food and nutrients coming in from the sea. (washing up, or growing on what's washed up, or eating what's pooped out by those who eat what's growing on what's washed up, etc. there's a whole shore ecology feeding an island). But in your case, your islands truly are closed systems - the "shores" are solid rock walls.

It's arguable that predators could even survive. A characteristic of most predators is that they need to have a large territory in which roam for their prey. Prey often outnumbered their predators by hundreds-to-one. You couldn't sustain a species in a limited area. There may be some counter examples on ocean islands but again, ocean islands are not closed systems.

If you find any complex lifeforms at all, you can expect them to be rare, and you can certainly expect them to be much smaller than their surface counterparts.

No birdoids, but you might find dragonflyoids. No horsoids, but you might find moloids. etc.

Then again, you might not even find trees. Why waste all that energy fighting gravity when there's no sun to climb towards?Come to think of it, realistically, this underground biosphere would likely not resemble a biosphere as we know it at all. It might simply be cavern after cavern of mossoids and slimoids, with the occasional moving critters like slugoids or insectoids. There not really a lot of evolutionary motivation to go anywhere. Which is kind of depressing: we might actually encounter an entire working biosphere, but it might look (and smell) like nothing more than a stagnant black bog.

Smell...

Ooh! Atmo! How will the atmo (and water bodies) get replenished?? All that biomass releasing waste products into a confined space. They'll poison themselves to death. This would further limit the population to that which is sustainable. Much like a modern fish tank with no filtration system will support a VERY few fish if the bioload doesn't exceed the tanks ability to convert toxins to harmless byproducts.

 

[Czcibor]

Good.

Writing time, the renegade AI had to write the virus before it was destroyed by others (i don't want it to guide directly my heroes)

I see here one more idea. What about rogue AI, who do not actually care much about humans... just it kept the virus as way to guarantee not being killed by others.

I don't fully understand that.

You've got a an electronic device, responsible for some minor task, and produced in billions. Just it has got its own software, and inside it there is a virus. The attack comes from within...

Hmm i think they won't be well fed in the sewers neither. I like the regeneration part the best, although i don't know how it could be inserted into a developed lifeform?

In to developed? You'd have to rewrite the source code... I mean DNA... ;)
In DNA there should be additionally added a plan how the organism should look like. In case of any missing part, the nearby cells would turn into stemm cells and start growing that part back.
It would require insane detailed plan. Such system would in theory be somewhat cancer prone, as it would let cells to replicate. (in practice, if you can engineer genes well enough, then presumably cancer is eliminated earlier)

Another important part would be resist infections and drink polluted water. (They can destillate it, but anyway it is a good ability.)

Also reasonable.