E) Why build a disease research facility for a water borne pathogen on a water planet rather than in a sterile space environment?
Three reasons spring to mind.
1. Convenience. Since available evidence points to the planet being at least pretty close to what the Precursors needed for comfortable living themselves, it makes more sense to plant the base on the planet. Maintaining a space habitat is pricey - and not just in the monetary sense. You need to drag everything up there with you - air, water, food, fuel - the only thing you can get on-site is power, and that's assuming you have efficient solar cells. Put the base on the planet, though, and you have most of those problems handled right off. On top of that, it's clear the Precursors needed test subjects. Hauling a Reaper Leviathan up to orbit would be no small order, to say nothing of keeping it alive once you got it there.
2. Apathy. Okay, yes, the planet is teeming with life and is practically an unspoiled aquatic environment. ...so what? Since the Precursors built their base on the planet, we can tell that their desire for convenience overrode concerns about the environment. Consequently, the Precursor bases - and subsequent carar contamination - are an ultimate example of NIMBY. The NIMBY Principle, short for Not In My Back(Y)ard, states that most people really don't care about dirty industry, prisons, sewage treatment, or, yes, disease research facilities - so long as those things aren't right where those people live. Put them anywhere else, though, and those people cease caring about them. Those facilities aren't any safer, their deleterious qualities haven't gone away, but since they're out of sight, they're out of mind. (The more personal version of NIMBY is "as long as I don't crap in my own yard, I don't care where it lands.") So 4546B could be irreparably destroyed if carar got out. Who cares? We don't live there. We'll just quarantine it and write it off as a loss.
3. Contamination was the plan all along. Consider the planet by its qualities. Remote, uninhabited, effectively quarantined with relative ease, not hostile to the carar lifeform. If the controlled experiments to destroy carar failed, maybe the Precursors were willing to take the nuclear option: let it loose. See if natural selection can take care of it. Maybe something in this ecosystem is carar resistant and the controlled experiments missed it. Let carar run wild and see which organisms don't die. That tells us where to look. Thus, the accidental escape of carar isn't exactly a huge setback; it's not what the Precursors were planning at that point, but it's only a minor inconvenience. As a result, 4546B is a planetary petri dish, and the experiment is still running. The Precursors could well be planning on returning - taking appropriate protective measures - to see if any of the native life on the planet had managed to beat carar. If so, then a cure might be forthcoming. If not, eh, let it cook some more.
As for asbestos skin or something similar to it...
It's not a bad idea, really. Asbestos transmits too much thermal energy (it's fireproof, but not heat-proof). However, we can hypothesize a body covering that might do the job.
Since we can infer Planet 4546B to have high concentrations of silica (evidenced by extensive quartz formations even in temperate waters), it's likely that the biology of the planet would have evolved to make some sort of use of it, at least under some conditions. A likely result being that rather than chitin, which forms the carapace of most exoskeletal creatures on Earth, is replaced with a silica-bearing compound on 4546B. (This is all the more likely if the organisms there are silicon-based.) Since all evolution is a matter of mutations that give a survival advantage, it's not inconceivable that a foam-like carapace would evolve. If this mutation was followed by another that resulted in a borosilicate exterior coating, it's essentially become a biological Space Shuttle tile.
There are three problems here, though:
1. The Lava Lizard doesn't have a carapace, it has skin. Silicon foam and borosilicate are not flexible.
2. Every gap in the structure would allow the infiltration of molten rock. Even a symbiotic insulator like that found in the Pompeii Worm won't work, since it would be incinerated.
3. Any exposed structures - the eyes, those snaggleteeth, and the webbing on its fins - wouldn't be able to withstand the temperature and would be destroyed the instant it hit the lava.
So, while with the proper (if unlikely) skin the lizard's core temp might stay in a survivable range, it would still be maimed as soon as it did a lava dive; delicate structures like eyes and fins just couldn't shed heat fast enough to avoid damage.
A careful examination of the model suggests:
- The eyes could actually be retracted and the eyelids sealed. There is more then enough space in the socket/lid arrangement for such a mechanism. Note also that the seal could be quite thick (using surface area to achieve tightness rather than perfectly closing).
- The fins could be made out of a fire resistant material and secreted from cells buried deeper in the tissues behind the skin
Two problems remain though:
- Lava will be about three times denser than water. Is it possible for the creature to force its way into it before popping back out? Probably. However, it is also incredibly viscous - so we'd need to find a lava which is molten at 500 degrees centigrade (or so) and which is very low in viscosity.
- The animal's mouth isn't protected (and it is spitting balls of rock)... so we need to rationalise that as well as the sea dragon. Perhaps the balls it spits are undergoing some kind of chemical reaction in the context of sea water? I don't know.
Sure you are, @Skope. Nobody's born knowing any of this. We ask questions and get answers...and if the answers don't make sense, we keep asking questions until they do. You're smart enough to learn anything you want to learn. Not saying it'll be easy or quick, necessarily, but you can if you want to.
A careful examination of the model suggests:
- The eyes could actually be retracted and the eyelids sealed. There is more then enough space in the socket/lid arrangement for such a mechanism. Note also that the seal could be quite thick (using surface area to achieve tightness rather than perfectly closing).
- The fins could be made out of a fire resistant material and secreted from cells buried deeper in the tissues behind the skin
Two problems remain though:
- Lava will be about three times denser than water. Is it possible for the creature to force its way into it before popping back out? Probably. However, it is also incredibly viscous - so we'd need to find a lava which is molten at 500 degrees centigrade (or so) and which is very low in viscosity.
- The animal's mouth isn't protected (and it is spitting balls of rock)... so we need to rationalise that as well as the sea dragon. Perhaps the balls it spits are undergoing some kind of chemical reaction in the context of sea water? I don't know.
If the eyelids were sufficiently thick and highly vascularized, such that bloodflow could act as a coolant for the eye's surface, then maybe. Nice catch.
The fins, though, pose their own problem. They have high surface area and low volume, making catastrophic heating extremely likely. Even Nomex melts at 350*C. Kevlar melts around 500*C. But there's another hitch...
While there is a single example of lava on Earth that's 500*C at time of surfacing, it doesn't look like lava as we're used to it - or as seen in game. It's not luminous; it looks more like mud or crude oil. Another problem comes up when we factor in lava's behavior as it cools: it becomes far more viscous. Taken together, it makes lava diving less and less believable.
As for spitting lava balls...that's a "maybe" with a bunch of caveats. Perhaps the mouth lining is protected, at least in part, by the Leidenfrost effect. Maybe the lizard keeps new water circulating into its mouth to keep down the water temperature in its mouth, avoiding burns, until it can spit the ball out. But if we're going to accept any of that, we'll have to accept that the temperature in that thing's mouth is going to be extremely high. This leads us to two unavoidable results:
1. Its skull, or at least its palate, is made from refractory materials to keep heat penetration into the body at a minimum.
2. Its brain isn't in its head. If it were, unless that skull is outstanding as a heat shield, it's going to cook its own brain.
Unfortunately, the lava lizard makes nearly no sense from a biological standpoint. Evolution tends toward more efficient, effective use of energy, because organisms that can better harness the energy they take in and expend less of it to do what it needs to in order to live will be more likely to survive to reproduce. What selection pressure is there for a lava-diving, lava-spitting lizard? Granted, it's not going to have a lot of predators, but such a developmentally-complex large body is a liability. Frankly, if the lava lizard were the size of, say, a tardigrade (a.k.a. "water bear," about 1.2mm at absolute most) and similarly constructed, I'd find it much more believable.
As it is, we already had a lava-spitting reptile: his name was Bowser, and he kept kidnapping Princess Peach.
While there is a single example of lava on Earth that's 500*C at time of surfacing, it doesn't look like lava as we're used to it - or as seen in game. It's not luminous; it looks more like mud or crude oil. Another problem comes up when we factor in lava's behavior as it cools: it becomes far more viscous. Taken together, it makes lava diving less and less believable.
Ah, yes - I thought so too. So I looked up pictures of the volcano at night (and it glows). I also read up on incandescence: It turns out that light emitted from bodies more than 500C in temperature moves from the infra-red range into the deep red range.
In an otherwise dark cave lava that would look dull be daylight should be quite visibly glowing. It should be a darker red - but maybe our diver has genetically engineered or evolved eyes? Easy to explain.
Viscosity on the other hand appears more serious problem - even at fairly high temperatures lava tends to be viscous enough that the ability of a creature to get more than a few centimetres in seems highly questionable!
As for spitting lava balls...that's a "maybe" with a bunch of caveats. Perhaps the mouth lining is protected, at least in part, by the Leidenfrost effect. Maybe the lizard keeps new water circulating into its mouth to keep down the water temperature in its mouth, avoiding burns, until it can spit the ball out. But if we're going to accept any of that, we'll have to accept that the temperature in that thing's mouth is going to be extremely high. This leads us to two unavoidable results:
1. Its skull, or at least its palate, is made from refractory materials to keep heat penetration into the body at a minimum.
2. Its brain isn't in its head. If it were, unless that skull is outstanding as a heat shield, it's going to cook its own brain.
It might be possibly to temporarily insulate the brain by having a void within the skull and heat sinks - it probably wouldn't be that hard for a few seconds.
Interesting to hear about the Leidenfrost effect - I didn't know its name (although I sometimes wet my hand before handling hot objects - so I clearly use it!)
Unfortunately, the lava lizard makes nearly no sense from a biological standpoint. Evolution tends toward more efficient, effective use of energy, because organisms that can better harness the energy they take in and expend less of it to do what it needs to in order to live will be more likely to survive to reproduce. What selection pressure is there for a lava-diving, lava-spitting lizard? Granted, it's not going to have a lot of predators, but such a developmentally-complex large body is a liability. Frankly, if the lava lizard were the size of, say, a tardigrade (a.k.a. "water bear," about 1.2mm at absolute most) and similarly constructed, I'd find it much more believable.
As it is, we already had a lava-spitting reptile: his name was Bowser, and he kept kidnapping Princess Peach.
Perhaps it evolved from a smaller creature and somehow is able to harvest energy during the cooling process? That would solve the calorie issue?
Ah, yes - I thought so too. So I looked up pictures of the volcano at night (and it glows). I also read up on incandescence: It turns out that light emitted from bodies more than 500C in temperature moves from the infra-red range into the deep red range.
In an otherwise dark cave lava that would look dull be daylight should be quite visibly glowing. It should be a darker red - but maybe our diver has genetically engineered or evolved eyes? Easy to explain.
@Avimimus I have to give you a lot of respect for the attempt, but I'm afraid I just can't buy it. When we look at objects aboard the Aurora, everything seems to be human-normal spectra. Which means that the lava we see is naturally a bright, lava-y yellow-orange...which means it's a lot hotter than 500C.
As for the color of low-temperature lava, yes, it's a "dull red," but that's a lot darker than the name implies. Incandescence is a fascinating subject (which is also very lengthy, so I won't bore you with it here), but "dull red" around 500C is visible in twilight or so as a very faint glow. Enough to see the material that's emitting the light, but definitely not enough to see your surroundings by, even in full dark. (Fun fact, in blacksmithing, there are fourteen distinct types of metal glow, each marking a specific temperature range. An experienced smith knows the temperature of iron or steel at a glance just by the color.)
It might be possibly to temporarily insulate the brain by having a void within the skull and heat sinks - it probably wouldn't be that hard for a few seconds.
Hmm...if the skull were very thick across the palate, and the palate was separated from the brain by voids filled with cerebrospinal fluid, and the CSF were kept in constant motion like a coolant (possibly by ciliary action?) then that would stretch the brain survival time. Quite possibly by enough to keep it alive even with a lava loogie in its mouth.
Perhaps it evolved from a smaller creature and somehow is able to harvest energy during the cooling process? That would solve the calorie issue?
There was a hypothesis advanced by Anthonie Muller in 1983 that thermosynthesis could be a means for an organism to harvest free energy to drive its metabolism. Essentially, he posited a biological heat engine. Now, insofar as we know, there are no thermosynthetic organisms on Earth, but that doesn't mean that there can't be any. After all, we found chemosynthesis a hard concept to swallow before we discovered black smoker ecosystems - even though it'd been proposed in 1890, we didn't actually discover it until 1977. Hell, we've found fungi that are radiosynthetic, deriving their metabolic energy from high-intensity gamma radiation. (True story. They're three fungi found inside the Chernobyl NPP in 1991. Lethal levels of radiation, and the fungi use it for food. Cryptococcus neoformans, Cladosporium sphaerospermum, and Wangiella dermatitidis, I think were the species.) So there's no way I'd rule out a thermosynthetic organism. Life is just way too tricky.
The only hitch is that an organism that is thermosynthetic wouldn't need to hunt; all of its metabolic energy is derived passively from its environment. It doesn't need to eat. So, unless it's highly territorial, it wouldn't need to attack, and since it's not in competition with anything for its diet, it shouldn't be that territorial. Oh...unless it's territorial about its breeding grounds. And if it's thermosynthetic and an egg-layer, then that would give it a reason to be territorial about its lava patch - to keep would-be predators away from its eggs.
While I'm still not on board with it swimming in lava, I'd say we've tied up the majority of the loose ends.
Well, since the Lava Lizard is a Cold-Blooded reptile, perhaps the body is maintained at a drastically lower temperature than normal?
*gleefully sprinkling Handwavium dust over the sheer implausibility of nearly everything in Subnautica*
My off-the-cuff hypothesis is that the Lava Lizards possess a biological mechanism that generates a cryogenic effect internally. The outer dermal layers of Lava Lizards have acquired high concentrations of aluminium oxide during the course of their evolution, coating their bodies with a flexible refractory layer that offers excellent thermal resistance. Bearing this in mind, their habit of diving into lava to form an additional coating of 'armour' can be explained (with a slight stretch of the imagination) by the fact that their contact with lava is typically momentary, the surrounding water would cool lava quite rapidly once these creatures have passed through the lava/steam/water interface, and their internal cryogenics would dissipate any residual heat in a relatively short time.
Well, since the Lava Lizard is a Cold-Blooded reptile, perhaps the body is maintained at a drastically lower temperature than normal?
*gleefully sprinkling Handwavium dust over the sheer implausibility of nearly everything in Subnautica*
Next question, please.
You're completely missing the point. This isn't nitpicking the game or trying to find holes in the narrative. It's about trying to come up with answers for questions, or at least plausible scientific explanations for in-game phenomena. The treknobabble "handwavium" answer is exactly what this academic exercise is meant to avoid - we're trying to apply real science to a fictional world and having a good deal of success (and no small amount of fun) at it.
Plus, if you read the posts so far, you'll see that "sheer implausibility" is seriously off-target; there are plausible explanations for most of the in-game items we've discussed.
It's fine if this isn't your cup of tea, but you don't need to run down those of us who are following the spirit of the question. Just don't play.
Well, since the Lava Lizard is a Cold-Blooded reptile, perhaps the body is maintained at a drastically lower temperature than normal?
Afraid not, @Enderguy059. A cold-blooded organism isn't "cold," per se. It just can't regulate its body temperature independent of its environment. If the environment is cold, the creature is cold. If it's swimming around in searing hot water...it's going to be searing hot, too, unless it can shed that heat in some way.
You do bring up an interesting point, though. Do we ever see the lizards outside of the Active Lava Zone?
Ah, yes - I thought so too. So I looked up pictures of the volcano at night (and it glows). I also read up on incandescence: It turns out that light emitted from bodies more than 500C in temperature moves from the infra-red range into the deep red range.
In an otherwise dark cave lava that would look dull be daylight should be quite visibly glowing. It should be a darker red - but maybe our diver has genetically engineered or evolved eyes? Easy to explain.
@Avimimus I have to give you a lot of respect for the attempt, but I'm afraid I just can't buy it. When we look at objects aboard the Aurora, everything seems to be human-normal spectra. Which means that the lava we see is naturally a bright, lava-y yellow-orange...which means it's a lot hotter than 500C.
Ah, you are making one assumption here: That the artificial lights and the spectra of 4546 are similar to those on earth!
The only hitch is that an organism that is thermosynthetic wouldn't need to hunt; all of its metabolic energy is derived passively from its environment. It doesn't need to eat. So, unless it's highly territorial, it wouldn't need to attack, and since it's not in competition with anything for its diet, it shouldn't be that territorial. Oh...unless it's territorial about its breeding grounds. And if it's thermosynthetic and an egg-layer, then that would give it a reason to be territorial about its lava patch - to keep would-be predators away from its eggs.
While I'm still not on board with it swimming in lava, I'd say we've tied up the majority of the loose ends.
Ah, but the viscosity issue! Is there any way to make molten rock less viscous (without creating conditions for cooling enough to develop a crust)? Then I'd say we'd dealt with it.
P.S. I wonder if the fireball attack of the sea dragon is actually a way to bait lava lizards? Kind of like an angler fish?
Well, since the Lava Lizard is a Cold-Blooded reptile, perhaps the body is maintained at a drastically lower temperature than normal?
*gleefully sprinkling Handwavium dust over the sheer implausibility of nearly everything in Subnautica*
My off-the-cuff hypothesis is that the Lava Lizards possess a biological mechanism that generates a cryogenic effect internally. The outer dermal layers of Lava Lizards have acquired high concentrations of aluminium oxide during the course of their evolution, coating their bodies with a flexible refractory layer that offers excellent thermal resistance. Bearing this in mind, their habit of diving into lava to form an additional coating of 'armour' can be explained (with a slight stretch of the imagination) by the fact that their contact with lava is typically momentary, the surrounding water would cool lava quite rapidly once these creatures have passed through the lava/steam/water interface, and their internal cryogenics would dissipate any residual heat in a relatively short time.
Next question, please.
Interesting ideas. I'll add them to the first post.
Not anymore (they were apparently used for stalkers for a while).
Oh well. That could've been an explanation for how they regulate body temperature, taking "cold soaks" outside of the lava zone, but that's out the window. Dang.
Ah, you are making one assumption here: That the artificial lights and the spectra of 4546 are similar to those on earth!
Granted, but it's a likely assumption. We really don't have much of a need to change our visual spectrum; we have equipment to sense non-visible wavelengths, so it's a lot simpler to use a device rather than genetically re-engineer our retinas. Occam's Razor, you know.
Honestly, that's a good answer. Some micronutrient it derives from the environment around lava pools.
Actually...now that I think on it, it makes sense. Let's assume the lava lizard started out fairly small. As successive generational mutations increased in size, it needs correspondingly increasing levels of calories and other nutrients. Some micronutrient in its system, which was in adequate supply in the general environment when it was smaller, became a limiting factor as the species grew. This nutrient is available in higher quantities in lava pools, hence why it gravitates toward them. Almost like a grazing area.
Nice idea!
Another possibility just occurred to me. If the lizard has less-effective enzymes - or lacks them for the most part - it needs more free energy to fuel metabolic reactions. Enzymes are used to decrease the necessary activation energy for biochemical reactions to "manageable" levels. Without them, organisms would need exponentially more free energy to perform those reactions. If the lizard really is thermotropic, then it's possible that it actually needs high temperatures not just for energy production (such as ATP synthesis) but also to make up for enzyme deficiency. Its biochemistry operates at a temperature an order of magnitude above Earth normal. It would also help to explain why it would carry a cooling lava carapace; it's essentially a thermal battery.
Ah, but the viscosity issue! Is there any way to make molten rock less viscous (without creating conditions for cooling enough to develop a crust)? Then I'd say we'd dealt with it.
P.S. I wonder if the fireball attack of the sea dragon is actually a way to bait lava lizards? Kind of like an angler fish?
Sure; up the temperature. Magma/lava viscosity decreases as temperature increases. But maybe we can modify the density without changing the lava itself.
Watching the lizard's behavior during a lava dive, there's a distinct dark "smoke plume" above the lava where the lizard is "swimming." Now this is pure spitballing, but if the lizard were to take in a large amount of water prior to diving into the lava, then constantly "exhale" this water while in the lava, it could be producing a lava/water mixture to swim through. The dust cloud we can see is potentially composed of particles of cooled lava ejected by the pressure created by the water, exhaled by the lizard, expanding as it heats, but because of the lava's immense thermal reserve, the bulk of it doesn't cool enough to harden. It's functionally similar to air entrainment, which is used to reduce the density of a lot of products, most commonly ice creams. By entraining air in the mixture (commonly called "churning" even though it really isn't), the overall density is reduced, making the ice cream easier to scoop and eat. The lizard could be working on a similar process to enable it to swim in lava; it's creating a channel of less-dense, slightly cooler lava through which to swim.
P.S. Maybe, especially if the lizard sees mostly in the IR section of the spectrum. IR penetration in seawater sucks, but if they're sensitive to it (in order to find viable lava sources), it's certainly possible!
the pressure and temperature rise; if the atmospheric pressure is higher than 1 atm, the pressure and temperature rise still further. If gravity is higher than 1G (definitely possible), pressure and temperature could soar as the previous two variables combine with high gravity to spike the pressure at depth. Average lava on Earth is about 700 degrees C, but can vary due to composition. Assuming relatively "thin" lava (low concentrations of basalt and silica), the effective temperature of the lava falls, potentially to the point where its temperature does not pass the vapor pressure at depth.
Wrong.
There is a thing called "critical point" on pressure-temperature diagram. After certain temperature, no matter how you raise the pressure liquid will become a gas. For earth ocean water this point is around 400 degrees C.
My suggestion was that the liquid at the bottom of the Subnautica ocean is not a water but something else entirely. We need an inorganic chemist here to point out what this liquid could be.
As for lava colour, it is caused by thermal radiation. So it doesn't matter what lava composition will be, to glow red anything must be about 700 C.
There is a thing called "critical point" on pressure-temperature diagram. After certain temperature, no matter how you raise the pressure liquid will become a gas. For earth ocean water this point is around 400 degrees C.
My suggestion was that the liquid at the bottom of the Subnautica ocean is not a water but something else entirely. We need an inorganic chemist here to point out what this liquid could be.
As for lava colour, it is caused by thermal radiation. So it doesn't matter what lava composition will be, to glow red anything must be about 700 C.
Not exactly, sorry. Beyond the critical point, the material in question doesn't become a gas; it becomes a supercritical fluid. In that state, its behaviors become very strange compared to the states of matter we're largely comfortable with, but is really a combination of liquid and gas behaviors. Its diffusion rates reach those of the vapor state, while molecular collision and tendency to dissolve solutes are those of the liquid state.
Black smokers are believed to be natural sources of supercritical water here on Earth, although we don't have equipment robust enough to verify that (yet). Supercritical water is also used in destroying particularly troublesome toxic wastes, like PCBs. The water, despite pressure and heat placing it beyond the critical point, is still behaving essentially as a liquid under those conditions. (Black smoker "smoke" is mineral precipitate.)
Not exactly, sorry. Beyond the critical point, the material in question doesn't become a gas; it becomes a supercritical fluid. In that state, its behaviors become very strange compared to the states of matter we're largely comfortable with, but is really a combination of liquid and gas behaviors. Its diffusion rates reach those of the vapor state, while molecular collision and tendency to dissolve solutes are those of the liquid state.
As far as I remember thermodynamics course (that was damn long time ago I must admit) at supercritical state substance behave more like a gas than a fluid.
And its definitely not what we see in lava zones in Subnautica
I mean we never see that water behave somehow different.
As far as I remember thermodynamics course (that was damn long time ago I must admit) at supercritical state substance behave more like a gas than a fluid.
I mean we never see that water behave somehow different.
I think we found the snag, Mr. Endar! "Fluid" and "liquid" aren't interchangeable terms. Fluids are any substances that continually deform while under shear stress. Consequently, gases, liquids, plasmas...all are fluids. Even so, you're remembering well; insofar as diffusion is concerned, a supercritical fluid has diffusion rates highly reminiscent of the material's vaporous/gaseous state. But its molecular activity - molecular collision rates, inertial energies - are more like the material's liquid state. Supercritical water still behaves like water...unless you ease off the pressure too far. Then it explosively vaporizes and, well, nobody's having a good day at that point.
As far as I remember thermodynamics course (that was damn long time ago I must admit) at supercritical state substance behave more like a gas than a fluid.
I mean we never see that water behave somehow different.
I think we found the snag, Mr. Endar! "Fluid" and "liquid" aren't interchangeable terms. Fluids are any substances that continually deform while under shear stress. Consequently, gases, liquids, plasmas...all are fluids. Even so, you're remembering well; insofar as diffusion is concerned, a supercritical fluid has diffusion rates highly reminiscent of the material's vaporous/gaseous state. But its molecular activity - molecular collision rates, inertial energies - are more like the material's liquid state. Supercritical water still behaves like water...unless you ease off the pressure too far. Then it explosively vaporizes and, well, nobody's having a good day at that point.
In my native language (that happens to be the language I received my education in) both liquid and fluid are the same thing=) but point taken anyway, thanks.
So you are saying that from point of view of diver it would be no difference between regular and supercritical water?
btw I was always under impression that water in supercritical state will be less dense than regular water (under slightly lower temperature), so it won't stay at the bottom. Am I wrong?
So you are saying that from point of view of diver it would be no difference between regular and supercritical water?
btw I was always under impression that water in supercritical state will be less dense than regular water (under slightly lower temperature), so it won't stay at the bottom. Am I wrong?
No; you're quite right. Instead of just rising like normal hot water, though, it'll diffuse and cool (relatively speaking) as it blends with the ambient water.
In its supercritical state, water still looks like water so visually there wouldn't be any indication...although being parboiled alive might give the diver a clue that something's going on. At over 374C and a pressure north of 218 atmospheres, there should definitely be a "NO SWIMMING" sign somewhere.
Not anymore (they were apparently used for stalkers for a while).
Oh well. That could've been an explanation for how they regulate body temperature, taking "cold soaks" outside of the lava zone, but that's out the window. Dang.
Actually, given the ability of water to absorb heat, at the depths involved most of the surrounding water should be 3-4 degrees - so any dark corner would allow a 'cold soak'.
Ah, you are making one assumption here: That the artificial lights and the spectra of 4546 are similar to those on earth!
Granted, but it's a likely assumption. We really don't have much of a need to change our visual spectrum; we have equipment to sense non-visible wavelengths, so it's a lot simpler to use a device rather than genetically re-engineer our retinas. Occam's Razor, you know.
But given that they have the technology to do it extremely easily - perhaps they have engineered people to have a different baseline for practical or compatibility reasons. You'd then use technology to see better in 'normal' wavelengths. Imagine, for instance, if you could engineer everyone to have superior vision (including in the IR, and UV range, along with seeing polarisation, and have quadrochromatic vision?) but at the cost of everyone being short-sighted and needing glasses to see at medium-long range. If a lot of your life is on a ship or in merky waters then this might not be a bad tradeoff.
Another possibility just occurred to me. If the lizard has less-effective enzymes - or lacks them for the most part - it needs more free energy to fuel metabolic reactions. Enzymes are used to decrease the necessary activation energy for biochemical reactions to "manageable" levels. Without them, organisms would need exponentially more free energy to perform those reactions. If the lizard really is thermotropic, then it's possible that it actually needs high temperatures not just for energy production (such as ATP synthesis) but also to make up for enzyme deficiency. Its biochemistry operates at a temperature an order of magnitude above Earth normal. It would also help to explain why it would carry a cooling lava carapace; it's essentially a thermal battery.
That might work somewhat. The big problem with high body temperatures is that enzymes break down (including those used in ATP processing). I forget the exact ratios but Ostriches have to replace their enzymes at several times the rate for each degree of body temperature increase during the day. I think in the hottest weather some enzymes are being completely replaced several times per day (which takes a lot of energy).
Ah, but the viscosity issue! Is there any way to make molten rock less viscous (without creating conditions for cooling enough to develop a crust)? Then I'd say we'd dealt with it.
P.S. I wonder if the fireball attack of the sea dragon is actually a way to bait lava lizards? Kind of like an angler fish?
Sure; up the temperature. Magma/lava viscosity decreases as temperature increases. But maybe we can modify the density without changing the lava itself.
Watching the lizard's behavior during a lava dive, there's a distinct dark "smoke plume" above the lava where the lizard is "swimming." Now this is pure spitballing, but if the lizard were to take in a large amount of water prior to diving into the lava, then constantly "exhale" this water while in the lava, it could be producing a lava/water mixture to swim through. The dust cloud we can see is potentially composed of particles of cooled lava ejected by the pressure created by the water, exhaled by the lizard, expanding as it heats, but because of the lava's immense thermal reserve, the bulk of it doesn't cool enough to harden. It's functionally similar to air entrainment, which is used to reduce the density of a lot of products, most commonly ice creams. By entraining air in the mixture (commonly called "churning" even though it really isn't), the overall density is reduced, making the ice cream easier to scoop and eat. The lizard could be working on a similar process to enable it to swim in lava; it's creating a channel of less-dense, slightly cooler lava through which to swim.
P.S. Maybe, especially if the lizard sees mostly in the IR section of the spectrum. IR penetration in seawater sucks, but if they're sensitive to it (in order to find viable lava sources), it's certainly possible![/quote]
Indeed.
I've also been watching a bunch of dives and they seem to just skate on the surface (unlike the Sandshark) - so viscosity might be of limited relevance.
Comments
My reaction exactly
I'm not smart enough for all this deep thinking.
1. Convenience. Since available evidence points to the planet being at least pretty close to what the Precursors needed for comfortable living themselves, it makes more sense to plant the base on the planet. Maintaining a space habitat is pricey - and not just in the monetary sense. You need to drag everything up there with you - air, water, food, fuel - the only thing you can get on-site is power, and that's assuming you have efficient solar cells. Put the base on the planet, though, and you have most of those problems handled right off. On top of that, it's clear the Precursors needed test subjects. Hauling a Reaper Leviathan up to orbit would be no small order, to say nothing of keeping it alive once you got it there.
2. Apathy. Okay, yes, the planet is teeming with life and is practically an unspoiled aquatic environment. ...so what? Since the Precursors built their base on the planet, we can tell that their desire for convenience overrode concerns about the environment. Consequently, the Precursor bases - and subsequent carar contamination - are an ultimate example of NIMBY. The NIMBY Principle, short for Not In My Back(Y)ard, states that most people really don't care about dirty industry, prisons, sewage treatment, or, yes, disease research facilities - so long as those things aren't right where those people live. Put them anywhere else, though, and those people cease caring about them. Those facilities aren't any safer, their deleterious qualities haven't gone away, but since they're out of sight, they're out of mind. (The more personal version of NIMBY is "as long as I don't crap in my own yard, I don't care where it lands.") So 4546B could be irreparably destroyed if carar got out. Who cares? We don't live there. We'll just quarantine it and write it off as a loss.
3. Contamination was the plan all along. Consider the planet by its qualities. Remote, uninhabited, effectively quarantined with relative ease, not hostile to the carar lifeform. If the controlled experiments to destroy carar failed, maybe the Precursors were willing to take the nuclear option: let it loose. See if natural selection can take care of it. Maybe something in this ecosystem is carar resistant and the controlled experiments missed it. Let carar run wild and see which organisms don't die. That tells us where to look. Thus, the accidental escape of carar isn't exactly a huge setback; it's not what the Precursors were planning at that point, but it's only a minor inconvenience. As a result, 4546B is a planetary petri dish, and the experiment is still running. The Precursors could well be planning on returning - taking appropriate protective measures - to see if any of the native life on the planet had managed to beat carar. If so, then a cure might be forthcoming. If not, eh, let it cook some more.
I couldn't resist...
Any time! This is fun.
A careful examination of the model suggests:
- The eyes could actually be retracted and the eyelids sealed. There is more then enough space in the socket/lid arrangement for such a mechanism. Note also that the seal could be quite thick (using surface area to achieve tightness rather than perfectly closing).
- The fins could be made out of a fire resistant material and secreted from cells buried deeper in the tissues behind the skin
Two problems remain though:
- Lava will be about three times denser than water. Is it possible for the creature to force its way into it before popping back out? Probably. However, it is also incredibly viscous - so we'd need to find a lava which is molten at 500 degrees centigrade (or so) and which is very low in viscosity.
- The animal's mouth isn't protected (and it is spitting balls of rock)... so we need to rationalise that as well as the sea dragon. Perhaps the balls it spits are undergoing some kind of chemical reaction in the context of sea water? I don't know.
Sure you are, @Skope. Nobody's born knowing any of this. We ask questions and get answers...and if the answers don't make sense, we keep asking questions until they do. You're smart enough to learn anything you want to learn. Not saying it'll be easy or quick, necessarily, but you can if you want to.
If the eyelids were sufficiently thick and highly vascularized, such that bloodflow could act as a coolant for the eye's surface, then maybe. Nice catch.
The fins, though, pose their own problem. They have high surface area and low volume, making catastrophic heating extremely likely. Even Nomex melts at 350*C. Kevlar melts around 500*C. But there's another hitch...
While there is a single example of lava on Earth that's 500*C at time of surfacing, it doesn't look like lava as we're used to it - or as seen in game. It's not luminous; it looks more like mud or crude oil. Another problem comes up when we factor in lava's behavior as it cools: it becomes far more viscous. Taken together, it makes lava diving less and less believable.
As for spitting lava balls...that's a "maybe" with a bunch of caveats. Perhaps the mouth lining is protected, at least in part, by the Leidenfrost effect. Maybe the lizard keeps new water circulating into its mouth to keep down the water temperature in its mouth, avoiding burns, until it can spit the ball out. But if we're going to accept any of that, we'll have to accept that the temperature in that thing's mouth is going to be extremely high. This leads us to two unavoidable results:
1. Its skull, or at least its palate, is made from refractory materials to keep heat penetration into the body at a minimum.
2. Its brain isn't in its head. If it were, unless that skull is outstanding as a heat shield, it's going to cook its own brain.
Unfortunately, the lava lizard makes nearly no sense from a biological standpoint. Evolution tends toward more efficient, effective use of energy, because organisms that can better harness the energy they take in and expend less of it to do what it needs to in order to live will be more likely to survive to reproduce. What selection pressure is there for a lava-diving, lava-spitting lizard? Granted, it's not going to have a lot of predators, but such a developmentally-complex large body is a liability. Frankly, if the lava lizard were the size of, say, a tardigrade (a.k.a. "water bear," about 1.2mm at absolute most) and similarly constructed, I'd find it much more believable.
As it is, we already had a lava-spitting reptile: his name was Bowser, and he kept kidnapping Princess Peach.
Ah, yes - I thought so too. So I looked up pictures of the volcano at night (and it glows). I also read up on incandescence: It turns out that light emitted from bodies more than 500C in temperature moves from the infra-red range into the deep red range.
In an otherwise dark cave lava that would look dull be daylight should be quite visibly glowing. It should be a darker red - but maybe our diver has genetically engineered or evolved eyes? Easy to explain.
Viscosity on the other hand appears more serious problem - even at fairly high temperatures lava tends to be viscous enough that the ability of a creature to get more than a few centimetres in seems highly questionable!
It might be possibly to temporarily insulate the brain by having a void within the skull and heat sinks - it probably wouldn't be that hard for a few seconds.
Interesting to hear about the Leidenfrost effect - I didn't know its name (although I sometimes wet my hand before handling hot objects - so I clearly use it!)
Perhaps it evolved from a smaller creature and somehow is able to harvest energy during the cooling process? That would solve the calorie issue?
@Avimimus I have to give you a lot of respect for the attempt, but I'm afraid I just can't buy it. When we look at objects aboard the Aurora, everything seems to be human-normal spectra. Which means that the lava we see is naturally a bright, lava-y yellow-orange...which means it's a lot hotter than 500C.
As for the color of low-temperature lava, yes, it's a "dull red," but that's a lot darker than the name implies. Incandescence is a fascinating subject (which is also very lengthy, so I won't bore you with it here), but "dull red" around 500C is visible in twilight or so as a very faint glow. Enough to see the material that's emitting the light, but definitely not enough to see your surroundings by, even in full dark. (Fun fact, in blacksmithing, there are fourteen distinct types of metal glow, each marking a specific temperature range. An experienced smith knows the temperature of iron or steel at a glance just by the color.)
Hmm...if the skull were very thick across the palate, and the palate was separated from the brain by voids filled with cerebrospinal fluid, and the CSF were kept in constant motion like a coolant (possibly by ciliary action?) then that would stretch the brain survival time. Quite possibly by enough to keep it alive even with a lava loogie in its mouth.
There was a hypothesis advanced by Anthonie Muller in 1983 that thermosynthesis could be a means for an organism to harvest free energy to drive its metabolism. Essentially, he posited a biological heat engine. Now, insofar as we know, there are no thermosynthetic organisms on Earth, but that doesn't mean that there can't be any. After all, we found chemosynthesis a hard concept to swallow before we discovered black smoker ecosystems - even though it'd been proposed in 1890, we didn't actually discover it until 1977. Hell, we've found fungi that are radiosynthetic, deriving their metabolic energy from high-intensity gamma radiation. (True story. They're three fungi found inside the Chernobyl NPP in 1991. Lethal levels of radiation, and the fungi use it for food. Cryptococcus neoformans, Cladosporium sphaerospermum, and Wangiella dermatitidis, I think were the species.) So there's no way I'd rule out a thermosynthetic organism. Life is just way too tricky.
The only hitch is that an organism that is thermosynthetic wouldn't need to hunt; all of its metabolic energy is derived passively from its environment. It doesn't need to eat. So, unless it's highly territorial, it wouldn't need to attack, and since it's not in competition with anything for its diet, it shouldn't be that territorial. Oh...unless it's territorial about its breeding grounds. And if it's thermosynthetic and an egg-layer, then that would give it a reason to be territorial about its lava patch - to keep would-be predators away from its eggs.
While I'm still not on board with it swimming in lava, I'd say we've tied up the majority of the loose ends.
Suspending one's disbelief for the purpose of being entertained isn't exactly a huge ask. Allow your minds to 'give' a little.
*gleefully sprinkling Handwavium dust over the sheer implausibility of nearly everything in Subnautica*
My off-the-cuff hypothesis is that the Lava Lizards possess a biological mechanism that generates a cryogenic effect internally. The outer dermal layers of Lava Lizards have acquired high concentrations of aluminium oxide during the course of their evolution, coating their bodies with a flexible refractory layer that offers excellent thermal resistance. Bearing this in mind, their habit of diving into lava to form an additional coating of 'armour' can be explained (with a slight stretch of the imagination) by the fact that their contact with lava is typically momentary, the surrounding water would cool lava quite rapidly once these creatures have passed through the lava/steam/water interface, and their internal cryogenics would dissipate any residual heat in a relatively short time.
Next question, please.
http://www.azom.com/properties.aspx?ArticleID=52
You're completely missing the point. This isn't nitpicking the game or trying to find holes in the narrative. It's about trying to come up with answers for questions, or at least plausible scientific explanations for in-game phenomena. The treknobabble "handwavium" answer is exactly what this academic exercise is meant to avoid - we're trying to apply real science to a fictional world and having a good deal of success (and no small amount of fun) at it.
Plus, if you read the posts so far, you'll see that "sheer implausibility" is seriously off-target; there are plausible explanations for most of the in-game items we've discussed.
It's fine if this isn't your cup of tea, but you don't need to run down those of us who are following the spirit of the question. Just don't play.
Afraid not, @Enderguy059. A cold-blooded organism isn't "cold," per se. It just can't regulate its body temperature independent of its environment. If the environment is cold, the creature is cold. If it's swimming around in searing hot water...it's going to be searing hot, too, unless it can shed that heat in some way.
You do bring up an interesting point, though. Do we ever see the lizards outside of the Active Lava Zone?
Not anymore (they were apparently used for stalkers for a while).
Ah, you are making one assumption here: That the artificial lights and the spectra of 4546 are similar to those on earth!
Vitamins?
Ah, but the viscosity issue! Is there any way to make molten rock less viscous (without creating conditions for cooling enough to develop a crust)? Then I'd say we'd dealt with it.
P.S. I wonder if the fireball attack of the sea dragon is actually a way to bait lava lizards? Kind of like an angler fish?
Interesting ideas. I'll add them to the first post.
Oh well. That could've been an explanation for how they regulate body temperature, taking "cold soaks" outside of the lava zone, but that's out the window. Dang.
Granted, but it's a likely assumption. We really don't have much of a need to change our visual spectrum; we have equipment to sense non-visible wavelengths, so it's a lot simpler to use a device rather than genetically re-engineer our retinas. Occam's Razor, you know.
Honestly, that's a good answer. Some micronutrient it derives from the environment around lava pools.
Actually...now that I think on it, it makes sense. Let's assume the lava lizard started out fairly small. As successive generational mutations increased in size, it needs correspondingly increasing levels of calories and other nutrients. Some micronutrient in its system, which was in adequate supply in the general environment when it was smaller, became a limiting factor as the species grew. This nutrient is available in higher quantities in lava pools, hence why it gravitates toward them. Almost like a grazing area.
Nice idea!
Another possibility just occurred to me. If the lizard has less-effective enzymes - or lacks them for the most part - it needs more free energy to fuel metabolic reactions. Enzymes are used to decrease the necessary activation energy for biochemical reactions to "manageable" levels. Without them, organisms would need exponentially more free energy to perform those reactions. If the lizard really is thermotropic, then it's possible that it actually needs high temperatures not just for energy production (such as ATP synthesis) but also to make up for enzyme deficiency. Its biochemistry operates at a temperature an order of magnitude above Earth normal. It would also help to explain why it would carry a cooling lava carapace; it's essentially a thermal battery.
Sure; up the temperature. Magma/lava viscosity decreases as temperature increases. But maybe we can modify the density without changing the lava itself.
Watching the lizard's behavior during a lava dive, there's a distinct dark "smoke plume" above the lava where the lizard is "swimming." Now this is pure spitballing, but if the lizard were to take in a large amount of water prior to diving into the lava, then constantly "exhale" this water while in the lava, it could be producing a lava/water mixture to swim through. The dust cloud we can see is potentially composed of particles of cooled lava ejected by the pressure created by the water, exhaled by the lizard, expanding as it heats, but because of the lava's immense thermal reserve, the bulk of it doesn't cool enough to harden. It's functionally similar to air entrainment, which is used to reduce the density of a lot of products, most commonly ice creams. By entraining air in the mixture (commonly called "churning" even though it really isn't), the overall density is reduced, making the ice cream easier to scoop and eat. The lizard could be working on a similar process to enable it to swim in lava; it's creating a channel of less-dense, slightly cooler lava through which to swim.
P.S. Maybe, especially if the lizard sees mostly in the IR section of the spectrum. IR penetration in seawater sucks, but if they're sensitive to it (in order to find viable lava sources), it's certainly possible!
There is a thing called "critical point" on pressure-temperature diagram. After certain temperature, no matter how you raise the pressure liquid will become a gas. For earth ocean water this point is around 400 degrees C.
My suggestion was that the liquid at the bottom of the Subnautica ocean is not a water but something else entirely. We need an inorganic chemist here to point out what this liquid could be.
As for lava colour, it is caused by thermal radiation. So it doesn't matter what lava composition will be, to glow red anything must be about 700 C.
Not exactly, sorry. Beyond the critical point, the material in question doesn't become a gas; it becomes a supercritical fluid. In that state, its behaviors become very strange compared to the states of matter we're largely comfortable with, but is really a combination of liquid and gas behaviors. Its diffusion rates reach those of the vapor state, while molecular collision and tendency to dissolve solutes are those of the liquid state.
Black smokers are believed to be natural sources of supercritical water here on Earth, although we don't have equipment robust enough to verify that (yet). Supercritical water is also used in destroying particularly troublesome toxic wastes, like PCBs. The water, despite pressure and heat placing it beyond the critical point, is still behaving essentially as a liquid under those conditions. (Black smoker "smoke" is mineral precipitate.)
And its definitely not what we see in lava zones in Subnautica
I mean we never see that water behave somehow different.
I think we found the snag, Mr. Endar!
So you are saying that from point of view of diver it would be no difference between regular and supercritical water?
btw I was always under impression that water in supercritical state will be less dense than regular water (under slightly lower temperature), so it won't stay at the bottom. Am I wrong?
No; you're quite right.
In its supercritical state, water still looks like water so visually there wouldn't be any indication...although being parboiled alive might give the diver a clue that something's going on. At over 374C and a pressure north of 218 atmospheres, there should definitely be a "NO SWIMMING" sign somewhere.
Actually, given the ability of water to absorb heat, at the depths involved most of the surrounding water should be 3-4 degrees - so any dark corner would allow a 'cold soak'.
But given that they have the technology to do it extremely easily - perhaps they have engineered people to have a different baseline for practical or compatibility reasons. You'd then use technology to see better in 'normal' wavelengths. Imagine, for instance, if you could engineer everyone to have superior vision (including in the IR, and UV range, along with seeing polarisation, and have quadrochromatic vision?) but at the cost of everyone being short-sighted and needing glasses to see at medium-long range. If a lot of your life is on a ship or in merky waters then this might not be a bad tradeoff.
That might work somewhat. The big problem with high body temperatures is that enzymes break down (including those used in ATP processing). I forget the exact ratios but Ostriches have to replace their enzymes at several times the rate for each degree of body temperature increase during the day. I think in the hottest weather some enzymes are being completely replaced several times per day (which takes a lot of energy).
Sure; up the temperature. Magma/lava viscosity decreases as temperature increases. But maybe we can modify the density without changing the lava itself.
Watching the lizard's behavior during a lava dive, there's a distinct dark "smoke plume" above the lava where the lizard is "swimming." Now this is pure spitballing, but if the lizard were to take in a large amount of water prior to diving into the lava, then constantly "exhale" this water while in the lava, it could be producing a lava/water mixture to swim through. The dust cloud we can see is potentially composed of particles of cooled lava ejected by the pressure created by the water, exhaled by the lizard, expanding as it heats, but because of the lava's immense thermal reserve, the bulk of it doesn't cool enough to harden. It's functionally similar to air entrainment, which is used to reduce the density of a lot of products, most commonly ice creams. By entraining air in the mixture (commonly called "churning" even though it really isn't), the overall density is reduced, making the ice cream easier to scoop and eat. The lizard could be working on a similar process to enable it to swim in lava; it's creating a channel of less-dense, slightly cooler lava through which to swim.
P.S. Maybe, especially if the lizard sees mostly in the IR section of the spectrum. IR penetration in seawater sucks, but if they're sensitive to it (in order to find viable lava sources), it's certainly possible![/quote]
Indeed.
I've also been watching a bunch of dives and they seem to just skate on the surface (unlike the Sandshark) - so viscosity might be of limited relevance.