4 ms·

Thermite or alkaline metals will burn just fine under water. As long as you have an oxidizer, some combustible and a source of energy to kickstart the reaction,

by Elv13 9y ago

Thermite or alkaline metals will burn just fine under water. As long as you have an oxidizer, some combustible and a source of energy to kickstart the reaction, it will burn. Also, I don't see why fire is so important. It was important for us to better digest food, that's a concidence, nothing else. And so does electricity. If the water isn't saline (why would it be), then it is as good as air from an isolation PoV. I did put a motherboard in mineral oil at some point and it did work until the fan died. Other fluids that could make life possible are also good at being non conductive. Even in salt water, a circuit just has to be bigger or better isolated to work. electricity takes the path of least resistance. Vast distances in salt water vs a good conductor, at some point the good conductor will still win. We have undersea cables since centuries and they work. Then, about smelting and complex chemistry, hydrothermal vents provides both a source of energy and of complex chemicals.

pavel_lishin 9y ago
Salt isn't the only thing that makes water a conductor, is it? It's any ionic compound, and I imagine life isn't going to have a very easy start in pure water...
dogma1138 9y ago
And how would you refine aluminium for thermite under water or refine highly reactive alkaline metals? People here come at it from the wrong point of view which is the application of advanced technologies, expertise and knowledge applied to overcome environmental challenges. You need to look at it from an evolutionary point of view (both biological and technical). Show me a feasible technological evolutionary path to our current level of technology for a life form that is limited to living in a solvent this can be water, ammonia, liquid hydrocarbons or anything else similar. When I say technological life is likely to be very similar to us is not due to lack of imagination, and this isn't just my own opinion. Here are several other factors to account for the evolutionary path to a technological society. Gravity, no direct bounds on lower gravity other than the fact that low mass planets will have trouble holding an atmosphere. Limits on the upper bound are both biological very high gravity would restrict the development of fine appendages which would restrict tool making, and in general when a fall from any relatively small height could kill you it would likely force evolutionary paths that could likely be against the development of complex technical intelligence. This limit can be somewhat mitigated by atmospheric density that would provide buoyancy some what countering some of the direct affects of gravity but that's both limited and can impose limiting factors on it's own. Gravity also would impose a limit on the feasibility of rockets, chemistry is universal and the rocket equation combined with the available energy in chemical fuels would impose a limit on how massive a planet can be from which you could use rockets to go into space. Biological attributes, fine motor skills are pretty much a must for fine tool making which is a critical part of technical and biological advancements in intelligence. Sight is also likely a critical factor, while other types of sight than non light, and non visible light might be present coverage of most of the visible spectrum is likely going to be very common if not mandatory. The amount of information you can gain from the and near visible spectrum is much higher than any other forms of vision such as echo location. That information is both needed for inference of underlying properties of "things" as well as would serve as a catalyst for development of higher brain functions. And those are just a few examples, if you start looking at what conditions are either mandatory, beneficial or detrimental to the evolution of a technologically advanced species from both a biological and then technical/societal aspect you would end up with a much more limited spectrum of possible life forms and planets on which a species that can reach our own level of technology can evolve. Don't get me wrong a super intelligent organism spanning an entire planet that you could debate the meaning of life with until the cold death of the universe is possible, so is any other type of conscious or "philosophical" intelligence, but these types of life forms won't be building rockets or iPhones.
- Elv13 9y ago
  > And how would you refine aluminium for thermite under water or refine highly reactive alkaline metals? Refining aluminium is either done with the chemical baths process or electrolysis. Electrolysis works equally well in dielectric gas or liquid. Electricity can be generated under water, we do so on earth, it ain't hard. The chemical baths process does not require an atmosphere, so it has no impact if it's executed under water or above it. Remember, we use plenty of gas based chemical processes and we live in a gas. There is no reasons it cannot happen in liquid. > Gravity: low gravity Totally unrelated, waterworlds tend to have higher gravity. Buoyancy is also unrelated to cognitive capacity. The average cognitive capacity is marine mammals species is higher than the terrestrial one. > Gravity: appendages Octopuses appendages are better suited to manipulate objects while clinging on to hard surfaces than our gravity based limbs. Their body is soft yet capable of some level of rigidity on demand. It is perfectly adapted to low-G interaction. > Gravity also would impose a limit on the feasibility of rockets You are trying to force various things into your "technological species". I am limiting my argumentation to species capable of industrial scale civilizations (type 1). But assuming I ignore that and bite your sofism (as I did for fire, which was an equally invalid proposition). For highly horizontal lunches, you need to accelerate to reach the escape velocity delta-v, not fight gravity. It's harder, but not impossible, to do so in thick atmospheres with high gravity and heavy liquid payloads. Also, if the hypothetical planet had a thick molecular oxygen free atmosphere, a direct cycle nuke engines would work very, very well. You could accelerate to ~12km/s in high atmosphere is an ablative shield before starting the chemical rocket (necessary only for the [orbital] plane correction. That's half of what you need to reach Uranus or Neptune escape velocity. So it would reach EV in any waterworlds (higher gravity cause high pressure chiemicals to form instead of water, we know nothing about this type of chemistry beside "diamonds exists", we have no clue if life can develop in >= 1GPa). And before you say 12km/s is impossible, no, it's totally possible if your direct cycle run at a few hundreds thoundsand degrees. We are not crazy enough to try because such radiation kills us. Assuming the organism is better suited to cope with it and the fact that water would shield against most radiation anyway, it becomes a very viable way to reach extreme speeds. > Biological attributes, fine motor skills are pretty much a must for fine tool making which is a critical part of technical and biological advancements in intelligence. Yes, they also happen to evolve in any fluid, not just gases. Even Lobsters can be considered to have fine motor skills. Cephalopods have exceptional ones even compared to us. > Sight Sight is unrelated to the viscosity of the fluid. Different wavelenghts have different absorption rates when crossing matter. We are transparent to a wide range of the EM spectrum and air is opaque to an equally large one. The "best sight on earth" prize is awarded to some deep water shrimp species. Also, hearing, sight and smell can be combined in a "introspecting close environment without contact" category. We use hundreds of different type of sensors to perform that task, it is not limited to those 3. The animal kingdom evolved about a dozen such senses. Sonars/Lidars/Radars/Masdars and electrical field organs can replace sights and smell respectively. So all that to prove that the attributes you attach to intelligence have absolutely no relation with either intelligence itself or the viscosity or air. edit: s/MPa/GPa/

by Elv13 9y ago

pavel_lishin 9y ago

Salt isn't the only thing that makes water a conductor, is it? It's any ionic compound, and I imagine life isn't going to have a very easy start in pure water...

dogma1138 9y ago

And how would you refine aluminium for thermite under water or refine highly reactive alkaline metals? People here come at it from the wrong point of view which is the application of advanced technologies, expertise and knowledge applied to overcome environmental challenges. You need to look at it from an evolutionary point of view (both biological and technical). Show me a feasible technological evolutionary path to our current level of technology for a life form that is limited to living in a solvent this can be water, ammonia, liquid hydrocarbons or anything else similar. When I say technological life is likely to be very similar to us is not due to lack of imagination, and this isn't just my own opinion. Here are several other factors to account for the evolutionary path to a technological society. Gravity, no direct bounds on lower gravity other than the fact that low mass planets will have trouble holding an atmosphere. Limits on the upper bound are both biological very high gravity would restrict the development of fine appendages which would restrict tool making, and in general when a fall from any relatively small height could kill you it would likely force evolutionary paths that could likely be against the development of complex technical intelligence. This limit can be somewhat mitigated by atmospheric density that would provide buoyancy some what countering some of the direct affects of gravity but that's both limited and can impose limiting factors on it's own. Gravity also would impose a limit on the feasibility of rockets, chemistry is universal and the rocket equation combined with the available energy in chemical fuels would impose a limit on how massive a planet can be from which you could use rockets to go into space. Biological attributes, fine motor skills are pretty much a must for fine tool making which is a critical part of technical and biological advancements in intelligence. Sight is also likely a critical factor, while other types of sight than non light, and non visible light might be present coverage of most of the visible spectrum is likely going to be very common if not mandatory. The amount of information you can gain from the and near visible spectrum is much higher than any other forms of vision such as echo location. That information is both needed for inference of underlying properties of "things" as well as would serve as a catalyst for development of higher brain functions. And those are just a few examples, if you start looking at what conditions are either mandatory, beneficial or detrimental to the evolution of a technologically advanced species from both a biological and then technical/societal aspect you would end up with a much more limited spectrum of possible life forms and planets on which a species that can reach our own level of technology can evolve. Don't get me wrong a super intelligent organism spanning an entire planet that you could debate the meaning of life with until the cold death of the universe is possible, so is any other type of conscious or "philosophical" intelligence, but these types of life forms won't be building rockets or iPhones.

Elv13 9y ago
> And how would you refine aluminium for thermite under water or refine highly reactive alkaline metals? Refining aluminium is either done with the chemical baths process or electrolysis. Electrolysis works equally well in dielectric gas or liquid. Electricity can be generated under water, we do so on earth, it ain't hard. The chemical baths process does not require an atmosphere, so it has no impact if it's executed under water or above it. Remember, we use plenty of gas based chemical processes and we live in a gas. There is no reasons it cannot happen in liquid. > Gravity: low gravity Totally unrelated, waterworlds tend to have higher gravity. Buoyancy is also unrelated to cognitive capacity. The average cognitive capacity is marine mammals species is higher than the terrestrial one. > Gravity: appendages Octopuses appendages are better suited to manipulate objects while clinging on to hard surfaces than our gravity based limbs. Their body is soft yet capable of some level of rigidity on demand. It is perfectly adapted to low-G interaction. > Gravity also would impose a limit on the feasibility of rockets You are trying to force various things into your "technological species". I am limiting my argumentation to species capable of industrial scale civilizations (type 1). But assuming I ignore that and bite your sofism (as I did for fire, which was an equally invalid proposition). For highly horizontal lunches, you need to accelerate to reach the escape velocity delta-v, not fight gravity. It's harder, but not impossible, to do so in thick atmospheres with high gravity and heavy liquid payloads. Also, if the hypothetical planet had a thick molecular oxygen free atmosphere, a direct cycle nuke engines would work very, very well. You could accelerate to ~12km/s in high atmosphere is an ablative shield before starting the chemical rocket (necessary only for the [orbital] plane correction. That's half of what you need to reach Uranus or Neptune escape velocity. So it would reach EV in any waterworlds (higher gravity cause high pressure chiemicals to form instead of water, we know nothing about this type of chemistry beside "diamonds exists", we have no clue if life can develop in >= 1GPa). And before you say 12km/s is impossible, no, it's totally possible if your direct cycle run at a few hundreds thoundsand degrees. We are not crazy enough to try because such radiation kills us. Assuming the organism is better suited to cope with it and the fact that water would shield against most radiation anyway, it becomes a very viable way to reach extreme speeds. > Biological attributes, fine motor skills are pretty much a must for fine tool making which is a critical part of technical and biological advancements in intelligence. Yes, they also happen to evolve in any fluid, not just gases. Even Lobsters can be considered to have fine motor skills. Cephalopods have exceptional ones even compared to us. > Sight Sight is unrelated to the viscosity of the fluid. Different wavelenghts have different absorption rates when crossing matter. We are transparent to a wide range of the EM spectrum and air is opaque to an equally large one. The "best sight on earth" prize is awarded to some deep water shrimp species. Also, hearing, sight and smell can be combined in a "introspecting close environment without contact" category. We use hundreds of different type of sensors to perform that task, it is not limited to those 3. The animal kingdom evolved about a dozen such senses. Sonars/Lidars/Radars/Masdars and electrical field organs can replace sights and smell respectively. So all that to prove that the attributes you attach to intelligence have absolutely no relation with either intelligence itself or the viscosity or air. edit: s/MPa/GPa/