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The Impossibility of Intelligent Life

  1. Feb 8, 2015 #1
    I was reading an article the other day discussing the possibility of ever finding intelligent life elsewhere in the universe, and I was wondering about what conditions really do matter for intelligent, technologically advanced life. By technologically advanced, I mean basic Stone Age technology at the very least, not necessarily even modern technology. I've seen a lot of arguments that life might be completely different elsewhere and not even need such as liquid water or even oxygen in meaningful amounts.

    But that concept bugs me a bit. Looking at life here on Earth, it seems to me that all life has evolved on a rather ideal planet, at an ideal distance from an ideal star, within an ideal region of an ideal galaxy, located in an ideal galactic neighborhood in an ideal universe that had the perfect set of parameters to even allow for baryonic matter.

    That's an awful lot of perfect that has to fall into place to allow for not just life, but intelligent life to form.

    The reason the argument for very different types of intelligent life bugs me is the idea that water and oxygen might not be necessary for such life. Granted, there could be lifeforms that are silicon-based or what-have-you, but water is a rather special chemical. I guess my questions are:

    • Is there a chemical analogue for water? Is there anything that could substitute it biologically? And could any such analogue exist under different planetary conditions as a liquid?

    • Is there a possibility for fire without a significant amount of atmospheric oxygen? What else could be an "oxidizer"? I figure fire would be key for a civilization.

    • Is it really feasible for life to form if too close (higher radiation) or too far (less energy) to/from a star? Could the "Goldilocks Zone" have more to it than just enough heat for liquid water?

    • Does the type of water matter? If there were water on a planet that had a much higher concentration of Deuterium, would that biologically matter?

    • If the answer to all of the above were to point to an Earth-like type planet, does that still leave billions of possibilities, or does that really cut out the chance that intelligent life could have formed elsewhere? Could the Earth actually be special?
     
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  3. Feb 8, 2015 #2

    Bystander

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    You might want to take a look at cosmic abundances of elements.
    Earth sized planets with earth-type compositions and chemistries are going to be quite common.
     
  4. Feb 8, 2015 #3
    Intelligent design? ;)

    And more seriously if life is possible one planet per million, then those who live on the lucky planet feel superior. On the remaining 999 999 planets there is no one to be worried about.

    (I agree, there is a problem how to deal with lucky enough laws of physics)


    The guesses are:
    http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry#Non-water_solvents

    (there are solvents that look not bad, the tricky part is whether there is a place to build whole complicated biochemistry)


    It seems (based on evolution on Earth) that carbon based life needs high concentration of oxygen to seriously let multicelular organisms to evolve:
    http://en.wikipedia.org/wiki/Great_Oxygenation_Event

    There are ideas of tidal heating in exomoons.
    http://en.wikipedia.org/wiki/Europa_(moon)#Potential_for_extraterrestrial_life
    Just I fail to imagine aquatic creatures there trying to build a civilization. There might be problems with food storage, not mentioning fire ;)

    (non carbon based life should have different expectations)

    I'd guess that's something what can worked around by evolution, just enzymes would have to have a bit different properties.

    By occasion - lets imagine creatures living on a tidally locked planet, wondering whether intelligent life can evolve in so adverse and changing conditions where there is life/day cycle and seasons. :D
     
  5. Feb 8, 2015 #4

    Bandersnatch

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    This is the old puddle in a hole argument. Of course we're reasonably well-adapted to existence on Earth - we've evolved here. I don't know about the environment being ideal - the extinct 99.99% of species would probably disagree.

    This is a wholly pointless speculation. We've got one sample of life-bearing planet with one sample of species we call intelligent (by which we mean 'exactly like us'). There's too little data available to make sweeping generalisations about the possibility of extraterrestrial life, let alone intelligence.
     
  6. Feb 8, 2015 #5

    SteamKing

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    Well, for all those extinct species, there was a time when the environment was ideal for them ... until it wasn't, which is why they are no longer with us. :L

    We take for granted that what went on yesterday will continue tomorrow, and that's just wishful thinking.

    The dinosaurs thrived and flourished for 150 million years and then were gone in an instant, in geological terms. Yet, even over that vast span, there is no indication that dinosaurs ever evolved any more intelligence or instinct than was needed to survive and produce the next generation.

    It appears that what drove the evolution of what we humans call intelligence was a combination of factors in just the right proportions. The environment of our distant ancestors changed, but not so abruptly or completely that there was insufficient time for survivors to move to better surroundings and adapt to them.

    Even should all the factors on a given planet be conducive to the evolution of intelligent life, it all depends on a number of factors external to that planet. After all, it takes just one asteroid collision to wipe out millions, if not billions, of years of existence. Just ask the dinosaurs. ;)
     
  7. Feb 9, 2015 #6
    What's odd to me is that the only place we know life exists, it exists in a phenomenal number of ways including sentience. It's highly likely no other life exists in the solar system, and if it does its going to be exceptionally hard to find. The fact that this planet was inhabited by life far longer than it was intelligent life, should imply the likelihood of finding simple life greater than that of finding intelligent life, but so far we've not found a single cell of any form of life outside the planet.

    If we fail to find some fossilized evidence of life on mars, then IMO it doesn't bode well for the possibility of ever finding life anywhere. Not impossible, but highly unlikely given the massive distances of space and fact that mars appears the second most habitable place in the solar sytem.
     
  8. Feb 9, 2015 #7
    I guess the main point to raise here is that "intelligence" isn't necessarily the apex of evolution. Asking, "What are the odds of finding intelligent life?" is, to some extent, similar to asking, "What are the odds of finding life-forms which use echo-location?"

    Intelligent life exists here because one of the life forms evolved a higher capacity for forethought (and memory) and communication. There is no intrinsic need for intelligent life, therefore there is no real reason to expect it to be common at all among any inhabited planets out there.
     
  9. Feb 9, 2015 #8

    StatGuy2000

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    Limiting our discussion to the chance of finding life in any form (rather than intelligent life), it may well be the case that the probability that we will encounter such life within our solar system is indeed quite small. However, it is worth keeping in mind that there are many other solar systems other than the one we are in (billions of them). The questions would be the following:

    (1) Are conditions in Earth so exceptional or unusual that the probability of findings planets with similar characteristics in other solar systems is very small?

    (2) Can a slightly different configuration of the plant or solar system affect the probability of the existence of life in other solar systems?

    Question (1) is currently impossible to answer without knowing more about the characteristics of planets in other solar systems. The early indications based on observations from robotic probes is that planets like Earth (i.e. those possessing carbon, and possibly liquid water), may not be all that unusual in other solar systems, so at least there is the possibility that life could emerge there.

    Question (2) is currently also impossible to answer.
     
  10. Feb 9, 2015 #9
    I've just found one more challenge in your question: "finding". What counts as finding? I mean if let's say there is one intelligent civilization per a few galaxies, then finding them would be quite tricky.

    Not wholly - it's possible to make here a summary of what we know, even if this summary would be terribly short.
    Before Wolszczan publication concerning pulsar planets in 1992 whole discussion concerning exoplanets could have been stopped in the same manner.
     
  11. Feb 9, 2015 #10
    Yes I understand that, my point was that the distance of space, in those cases, are so massive that the chance we find life there are very small.

    If it's announced tomorrow that an exo planet of roughly earth size is found to have oxygen in its atmosphere and lie within the goldilocks zone, it still would not prove the existence life there. It would almost require the planet have intelligent life of its own to also detect our planet and we mutually send signals to each other.

    That's just incredibly unlikely to happen.
     
  12. Feb 10, 2015 #11
    Granted, but "finding" isn't important to my questions. I recognize that the universe could teem with life and we'd still never find it. I'm more interested in what it truly takes for a sentient form of life which can form a basic civilization to emerge on a planet.
     
  13. Feb 14, 2015 #12

    Drakkith

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    Unfortunately we only have 1 species to look at, so there's no telling.
     
  14. Feb 14, 2015 #13

    Nathanael

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    What is civilization? We may have ideas of what civilization is, but can we define the word universally? What really makes a civilization a civilization?

    I will explain what I think defines a civilization. To me it seems there is one main difference between the civilized and uncivilized worlds. Prior to civilization, every individual was independent. That is, when we were uncivilized 'hunters and gatherers,' every person was an expert at the entire culture. Every man knew how to hunt, cook, build, make clothes and tools, etc. But when civilization arose, independence was lost and everyone became largely dependent on everyone else. The advantage of this was that individuals became more specialized. Instead of everyone being an expert in everything, some people became experts in some things and others were experts in other things. Independence was traded for specialization. This, as we can clearly see, opened up a lot of potential for development.

    When I try to transcend our familiar human anecdote to define civilization universally, I come to the following general idea: Civilization is where a collection of individuals becomes dependent on each other by splitting up into groups of specialized functions. This enables more potential for growth than if each individual survived independently.
    This is just my perspective on the essence of civilization, so feel free to improve on it, or to propose alternate definitions of what you are looking for.

    One other example jumps out at me from this definition. Cells. Our cells have come together to form our bodies, and different groups of cells perform different functions, but all are dependent on all. (The heart couldn't live without the stomach and vice versa and etc.) So are cells considered a civilization? If not, then what is the requirement which they do not satisfy? (In other words, how do you define civilization?)

    Individual cells are to the human body as individual humans are to (civilized) humanity. The more I think about this analogy, the more aspects of it I find. Look at how much more potential the human body has compared with trillions of cells which survive independently. Look at how much more potential the human species has compared with billions of humans surviving independently. It almost seems like "civilization" is a natural progression of this living world.
     
  15. Feb 14, 2015 #14
    Here is my take on this.
    Firstly, look at how fast our civilization has developed in the last 10000 years. It's insanely fast compared to the lifetime of the universe. And then look at how our technology is advancing. It's advancing at an exponential rate. In the next 10000 years, we will definitely become a multi-planetary species, provided we don't wipe ourselves out. Who knows how advanced we will be.
    Assuming there is life out there, it will be either more intelligent or less intelligent than us.
    In the case that is is more intelligent, using our observation of our advancement of society, wouldn't it be fair to conclude that the intelligent life is extremely intelligent and vastly more advanced than us? 10000 years is a very short span, it is very very unlikely that there is a similar species advancing at the same pace as us. Thus, if it was an extremely intelligent species will it not have probably expanded outwards and displayed observable signs of it's existence?
    In the case that it is less intelligent, there are two scenarios.
    1. It is simple life, which is not the focus of this discussion.
    2. It is "stone age" intelligent. My argument here is the length of the stone age (3.4 million years) is only 0.0002 % of the universe's estimated lifetime. It's only a sample size of 1, but that's all we've got. If intelligent life only takes about 3.4 million years (plus minus tens of millions of years, its still tiny in comparison to the lifetime of the universe) to develop to become a highly intelligent species, there is a very low chance that intelligent life lies in the universe that has not developed into a highly intelligent species.

    Just my 2 cents, feel free to refute.
     
  16. Feb 14, 2015 #15
    That is a quite open ended question I think. You yourself could probably make a list right now of several basic features that you think a species would need to possess in order to at least have the capability to form a civilization. One thing that comes to my mind is cooperation amongst individuals to do tasks towards a set goal. Cooperation implies communication and understanding, and leadership and organization. Setting a goal implies the formulation of ideas. "Producing a civilization" implies that the ideas, tasks, and goals can't be too wacky ( have everyone dig a hole and then fill it up ) as an exercise in futility so as to not give an advantage to the group in one way or another. So I would think there has to be a certain social organization, and there could be a few, that could meet your criteria where a civilization comes about. Perhaps throw in some competition and conflict so that individuals can come up with better ideas, rather than follow around each other like zombies and re-hash the old stuff over and over again.

    Next you might have to look at body structure and features. Opposable thumbs and fingers, and upright stature, are often said to have worked great for human survival, for carrying things and manipulation of objects. But would tentacles work for another life form just as well? Could there really be an octopus alien species technologically adept at sending rockets to their moon?

    That is just form and function, and is complicated enough, without mentioning the necessary evolution and its steps to get to an intelligent life form.

    As you said,
     
  17. Feb 20, 2015 #16
    I really like your definition of civilization, but for the purposes of my question I am using a more basic definition, which would include cave-dwelling hunter-gatherers. I think, for the purposes of my question, I'd stick to a definition of civilization as being a species of sentient beings who have the ability to manipulate nature. The most basic form of that is creating fire, and so I use fire as a sort of "must have" for any civilization. The questions I pose aren't really focused on what kind of civilization really, just that one could emerge. I mean, once you have fire and tool use, there really is no limit to where a civilization can go. It could stay there, or it could evolve into a more technologically advanced society, with agriculture and cities. Either way, it's still a civilization compared to animals.

    And, yes, I think that cells are a form of civilization. I don't think most people realize that they as an organism are actually many organisms working together. Not just the human cells, but also the many microorganisms without which we'd not be able to live. But for this discussion, I am not considering non-sentient life forms as "civilizations". I am using the term to mean the ability to use tools and make fire...or some other manipulations of nature that are analogous.
     
  18. Feb 20, 2015 #17
    You're most likely correct of course, but I think my real question is, what can take the place of water, and what conditions will allow for fire? I figure those two things are absolutely necessary to biology (water or an analogue) and basic civilization (fire).
     
  19. Feb 20, 2015 #18

    Drakkith

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    Now that is a much more interesting question in my opinion. Unfortunately I haven't done much reading into this.
     
  20. Feb 20, 2015 #19
    You bring up some good points, and Stone Age is really all I am gunning for in my inquiry. The level of technology isn't important. The fact that any sort of "technology" can be advanced is all that matters, which is why I use fire as a requirement. That's about as basic as it gets.

    I like that you brought up intelligence. There seems to be an assumption that alien species would be more intelligent, and less popular that they would be less intelligent. I am not sure that is the case. Intelligence is something that is driven purely by evolutionary pressure. Once a species reaches the intelligence level that allowed for sentience, I am not sure that evolutionary pressure really matters anymore. Consider the human race...how does natural selection even enter into the equation with our species anymore? Stupidity isn't selected for naturally anymore, nor are any other traits that have no effect on procreation. I think once a species reaches sentience, there is no longer any evolutionary pressure to make them "smarter".

    Of course, I suppose if there were a planet where a lot of species were quite intelligent, it could cause a selection of higher intelligence to survive over lesser intelligence. But I am not sure it would be an order of magnitude such as the case between humans and the most intelligent animals. It's a sort of gap that once crossed no longer has any momentum to keep advancing.
     
  21. Feb 20, 2015 #20

    Evo

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