That, or the window of technological development that we can detect and are capable of recognizing as intelligent is very small. It's possible that superintelligence is all over the place, but we're unable to perceive or comprehend it, in the same way that a nematode is completely oblivious to human society. Once a society creates superintelligence, they might even "clean up" after themselves, so that traces of previous stages of their civilization aren't available for us to observe.
I don't think that's likely. Earth is billions of years old but we have just been around for a few thousand. If we an alien world had evolved just a few thousand years earlier, it could have colonized the galaxy by now. We can't possibly be synced that perfectly. All sorts of random events, like asteroid collisions, had a huge impact on the timing of our evolution.
>we're unable to perceive or comprehend it
That doesn't seem likely either. An advanced civilization could easily build many kinds of megastructures that would be detectable to us, like dyson spheres. I also think it's very unlikely they wouldn't interact with us. Either to help us if they were moral, or to exterminate us if they were not.
The fact the circumstances for intelligent beings took so long may have been random circumstance. There's no guarantee it would take that long on other planets to go from general life -> intelligent beings. The environments could easily be more welcoming to it, they may have had fewer extinction events restarting growth, etc, etc.
If it's as easy to make a nuclear-class weapon as it is to make a microwave, for example. That would probably be the end of us.
We're already kind of doing this with drugs and digital simulations...
Maybe it's not atypical that life-bearing planets don't end up producing a technologically advanced one. The Earth is an example of how a planet can have complex animal life for hundreds of millions of years without any of them being able to invent cake, and habitability is relatively temporary.
While possibly there aren’t that many restrictions on where life can evolve and even where can different levels of intelligence can evolve there are likely quite a bit of restrictions on where and how technological intelligence can evolve.
Which puts some restrictions or bias towards both biological/evolutionary traits and as well as environmental ones.
While I think we’ll find life in very strange places eventually and life that will be very strange any technological species we might encounter would be something much more similar to us than to anything else.
It would seem to me that techniques like hydraulics would emerge quickly, and large pressure and temperature differentials over small distances are considerably more common and easier to harness underwater than above. Fabrication is certainly harder, but not impossibly so. Some weapons like thrusting spears might be easier to make and more advantageous in the water than on land, and those developed pretty early for us.
Chemistry is virtually impossible underwater, were not talking about an octopus using a stick even some birds use tools that's not exactly what we would call a technological intelligence.
No fire, no smelting no metalworking, no complex materials.
Intelligence might also take different forms, so an ocean-sized equivalent of a termite colony comprised of specialised molluscs that were collectively intelligent and had selectively bred themselves into specialised roles for millennia could achieve a great deal?
Humans can do experiments in space because we have the technology to do so, show me an evolutionary path to technology capable of overcoming environmental barriers without fire and chemistry.
Your proposed alternative is to play "what if" until either I come up with an imaginary scenario that strikes your fancy or, more likely, you reject out of hand anything brought to you and claim to be right by default. Well, that's hogwash too. It's certainly no way to advance a scientific claim, let alone three of them.
I'm particularly skeptical of the claim that you could not develop chemistry underwater; it seems equally as implausible as saying that you could not develop chemistry in air for exactly the same reasons.
what? you think its possible to develop fire under water? chemistry? have you done any chemistry? what about electricity? (a huge but impossible one to do under water)? I am trying really hard not to say something mean
Electricity is far from impossible either to develop or use underwater, and in fact nature has already done so in the form of the electric eel. More to the point, many aquatic species have specially developed sense organs for electricity, increasing the odds of it being developed for communication.
Similarly, although it doesn't look much like your childhood campfire underwater lava flows can be stable and useful sources of heat great enough for refining ores and similar. Further shaping using hydraulic pressure (equivalent to waterjet cutting or forming) would hardly be unimaginable.
And please feel free to say your mean things-- it certainly can't damage my view of the evidence you've put forth so far.
sure, you can play lawyerball and say its possible.
yes, AFTER 40 THOUSAND YEARS, we humans have figured a lot of this stuff out in an easy environment. Sure, we can take the knowledge we have gained over the last 40k years, and do some stuff under water, because we have already figured it out.
i also hate your type of person. your the type of person that says: give me evidence, you are wrong until you give me evidence. but you provide none of your own.
But we've already had one such event-- the development of human intelligence. So if the random emergence of sentience from undirected physical processes is your bar for impossible, I'd say you need a new bar.
Regarding human technology, 40 thousand years is not a lot of time in the grand scheme of things. But even having said that, none of the claims I make rest on having human tech: the electric eel is not a human invention, nor are lorenzini organs. Use of a lava flow for heat is natural to many aquatic ecosystems, and requires no more intelligence than the ability to win at "hotter or colder". Many aquatic life forms already make use of simple hydraulic effects to move along the sea floor, anchor themselves into tidepools, or hunt prey. The preponderance of evidence we have for life on Earth suggests that that these skills will develop over time. Proposing that there is some reason that advancement inevitably stops under the sea is a bold and surprising claim, and yes-- requires evidence.
Regarding hating my type of person, that's on you. I think your position is narrow-minded and in error, but I'm pretty sure you're not Hitler.
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.
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.
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/
2. Different type of oxidation.
3. Work with air bubbles; people fished and dived since time immemorial not being able to survive underwater.
4. No one said the ocean has to be a water ocean, how about ammonia?
5. The first space launches of the hypothetical aquatic species may involve air-breathing animals, or it may be delayed until the automation reached a sufficiently high level.
The technological path is not linear. For example, the Aztecs had advanced societies and infrastructure but no utilitarian wheel: http://www.zoesaadia.com/real-smart-folks-but-no-wheel/.
So that would just move the same math down one more step. Twice the number of planets which have life (whether you adjust "can have life" or just the percent of the above which do), but that cancels out with half as many either being intelligent or releasing signals.
I don't understand why the aliens would waste power beaming directed and powerful signals into space.
Do you think the BBC bothers broadcasting enough signal for the Martians to listen to their radio? I don't think that's a very profitable business model.
> Octlantis is not in any sense a city. It is not a cooperatively built and maintained structure, designed to allow many individuals to live in close quarters. It is an unusually dense collection of individual dens, most of them dug into a bed of scallop shells.
does a hermit crab count?
Personally, I've always assumed less than 100% of life-bearing planets will have intelligent life. Earth would have failed less than 1M years ago, and our species may not be around for long.
The interesting question, to me, is how often does life arise? If we find two origins in our solar system... that would change everything.
Earth has an incredibly complex entropic ecosystem - sunlight, wind, rain/flowing water, lightning, tectonic plates recycling material, radioactive material, and lots of interesting molecules... it seems inevitable that life would evolve.
The Moon? Solar radiation, and maybe some chemical reactions driven by solar radiation. No life. Mercury? Too much solar radiation, destroys anything depending on small energy deltas. Mars? Above-average entropy channels in the past, but it's pretty dead now
I suspect it may be fairly common for life to occur in the forms of single celled organisms - just like extremophiles are rare but not unheard of on Earth.
OTOH I suspect it's incredibly rare for complex life (insects, small mammals etc) to form.
http://www.latimes.com/science/la-sci-earth-like-planets-201...
https://en.wikipedia.org/wiki/List_of_potentially_habitable_...
https://www.universetoday.com/49605/how-common-are-solar-sys...
This article says we're definitely weirder, but points out that the detection technology matters, and we may not have the full picture yet: https://planetplanet.net/2016/07/12/exactly-how-unusual-is-o...
Until we start getting probes out to solar systems or have some way to detect orbits of planets that aren't perpendicular to our own we won't have much of an idea how weird we truly are or aren't.