I'm starting to think that given enough time and space any context in which self replicating structures can occur will give rise to some form of life (as a statistical inevitability).
(I've probably been reading too much sci-fi.)
Alien life does not need to be restricted to matter as we know it; if space itself can give rise to self replicating structures, then it too could be alive.
Beyond that, life could occur in any medium and at any scale (in either space or time).
Even regarding terrestrial life, how long did it take for us to notice microbes (as something other than a curse from god)?
There could even be macroscopic lifeforms moving so quickly that we are unable to see them.
So the answer, as far as I can tell, is really that it depends on the kind of life we're referring too.
And if it's too far outside the human context of understanding or perception, then the answer is no.
By looking at what happened in earth judging it is a normal likelihood for a cell to form within billion year and evolve to us within 4 billion years, is nuts.
Scientists thinks this way because they have no idea about what statistical possibility of this to happen in such time.
What happened and happening in Earth even if not a miracle to one then it is result of a luck statistically impossible to find anywhere in cosmos.
It is worth to mention that all living beings in earth are descendants of same cell. Even in earth there is no sign of multiple different cell formation which shows how lucky we were.
You’re confusing the odds of a specific lottery ticket hitting the jackpot with any ticket winning. Someone will win fairly regularly.
So yea, the odds of life evolving to something genetically compatible with humanity when we did might be tiny, but we aren’t the only possible form of intelligent multicellular tool using life and it could have happened +/- a few billion years. Given earth starting 5 billion years ago the odds of some intelligent civilization eventually showing up might actually be fairly high, we just don’t have enough data to know.
I think you totally missed my point. I am literally saying there are Aliens only if GOD created them and it seems like there aren't.
Even though i tried to be very indirect for obvious reasons. I think it was clear enough.
Sure, that belief isn’t backed up by existing evidence but it’s hardly worth rehashing again.
Anyway something more interesting you said was the belief that all life came from a single cell. It’s unclear if all life ever to exist on earth had cells or if they evolved later. Also, we can’t tell if life showed up independently fairly frequently but was out competed or just once.
This is somewhat dependent on how life is defined. Prions replicate, but aren’t generally considered alive, yet being fairly simple they should have shown up quite frequently due to random chance. The more complex self replicating matter must be to be considered alive the higher the hurdle for life to have formed randomly but the more likely for simpler self replicating matter to evolve into life. Yet, saying evolution of non living mater results in life seems to twist the meaning around unpleasantly.
PS: Perhaps we should have a new definition between dead matter and living matter which is self catalyzing in the right environment. With viruses or prions siting at the complex side and crystals at the simple end.
Just once for the initial self-replicators would be my guess.
Not in a cell, but in porous rock around the hydrothermal vents (at the bottom of the ocean).
Given the exponentialish 'population' growth of chemical soup, coupled with the fact that the very low likelyhood of a localised self-replicator forming, by the time second place came about the game would already be over.
Far more likely is preserved 'mutations' to chemical replicators leading to divergent forms of demi-life.
> by the time second place came about the game would already be over.
That’s presumably true, but it means there could have been a very large number of losers not just 1. Aka if extremely primitive life showed up once on earth then it might be a rare event, if it happened 100 trillion times then most planets with the right conditions will have some form of life.
Even if it doesn't define life obviously replication is the thing here. Without capability of replication there is no continuation and even if some matter is alive it has limited time to obtain this ability. Which is actually seems like slightly more possible than impossible to me. Not saying straightforward impossible just because we exist.
Any non infinitessimal probability leads to certainty given enough time.
Consider it in terms of reactions per second - take the likelyhood of non-formation of replicators (call it 99.999999999% - because it actually does not matter), to the power of the number of reactors, to the power of the number of seconds since the universe began.
The likelyhood that no self-replicators form rapidly plummets to a vanishing value.
Not who you responded to, but I thought you described your case elegantly neutral to the God question. I suspected you were coming from that perspective, but your argument stood on its own.
Now that said, if we did find alien life, how would your feelings about God change?
I don't base existence of GOD on this. Simply GOD is only thing that does not need anything to be based on so it is possible to explain existence.
I was trying to point that evolution is statistically close to impossible (from my understanding) and GOD made it possible. Thus aliens are unlikely.
And it seems like there is no sign of aliens in holly books. If there was aliens and it was conflicting with holly books then it would mean that holly books i believe are fake however i am not saying that existence of Aliens would conflict with Holly books either (I am not sure about that).
The explanation of this existence to you is what GOD means to you. And you need to define some element to explain this existence. And what would you define eventually means GOD to you.
I don't believe you have read your "holly" books. There are plenty of alien beings described in detail in that book.
I also reject your out-of-hand assertion that whatever one thinks about the world's existence has the same meaning to someone as your mythical being has to you.
How blown would your mind be if I posited to you that what you call "GOD" is the universe? Your holly book says he is everywhere and everything all at once, does it not? That "He is within all of us", and yet we are the universe observing itself. He came about out of nowhere with no trace of origin? We don't know what caused the big bang, it just happened.
If aliens exist, it's because the universe "allowed" it to happen (aka the statistical probability is high enough for it to occur or we would not be alive having this conversation) not some conscious divine being.
Which logically means your definition of GOD would include a non sentient physical processes that lacks a free will etc. At that point why label it GOD rather than say space time or whatever?
Existence of universe has nothing to do with something about universe. Or at leas not have to. You cannot explain existence of space time with space time
That’s one model, but we really don’t know what happened before the Big Bang.
Still labeling pre Big Bang as SpaceTimeTime or calling that Space Time and relabeling what we experience as local space time doesn’t really matter here. The point is our Big Bang could be happening infinite times in a multiverse without beginning or end. That’s one possibility where there isn’t anything conscious to point to as a GOD just the same kind of things which make up physical reality.
A chemical soup and enough porous rocks down at the bottom of the ocean to operate as reactors powering endothermic reactions.
These are spread across the entire surface of the earth.
If, by chance, some set of reactions occur forming molecules (or groups of molecules) that catalyse their own formation, then you have constrained self-replication.
Once you have this - and you only need it once, there's an exponential (s-curve really) boom in the prevalence of the chemicals in question.
Any changes to these molecules that preserve the self-replicating nature of the soup will be preserved to an extent and those changes that improve self-replication will not only be preserved but will begin to outpace the parents.
If, for example, I stick a little hydrogen on the front of a structure it'll develop the ability to trace along ion lines.
A chemical soup that hunts its own food.
Of course, these mutations can lead to divergence - which eventually leads to a pseudo-competition.
Step by step, piece by piece, complexity builds up.
Structures integrate and develop the ability to funnel 'food' to where it needs to go for transformation.
And if it is possible for this to happen, then given enough time and enough distinct reactors, it is not simply possible - it is absolutely inevitable.
I'd note that nothing in this statement is particularly compelling one way or the other. Sure, things are inevitable given enough space and enough time. But we had a finite amount of space and a finite amount of time. Both were pretty big numbers. But do we have evidence to say that the timelines of life on Earth were inevitable? Probably not. Maybe, but I would guess no.
Yet all living beings in earth are descendants of same cell, as far as we know. So if the above can happen once -- even if only "needs" to happen once, why would it not occur more than once, and lead to different "lines" of life, so to speak?
I suspect that the less evolved and less efficient replicators would not fare well against older and more robust forms - especially once those forms develop the ability to hunt and direct their food.
Basically, in an emergent adversarial environment running late to the party gets you eaten.
I don't know much but i think you are jumping too much. I don't think it is possible for a self-catalysing molecule to achieve enough complexity to begin with. When you jump to structure obviously it becomes pretty much irrelevent.
> It is worth to mention that all living beings in earth are descendants of same cell. Even in earth there is no sign of multiple different cell formation which shows how lucky we were.
I don't see why this has to be the case. If unlikely conditions are correct for something unlikely to occur, then it's not longer unlikely to occur multiple times.
E.g. if you play around with chemical reactions and you hit the right conditions, it usually happens all over the place, and not just one molecule combining.
We don't even really have an agreed-upon definition of life, so the question is basically non-sensical. Alive are the things we say are alive, which is mostly stuff like us: some type of metabolism, growth, response to stimuli. By that definition we would certainly recognize it, at least up close.
If we're willing to expand the definition of life, e.g. to accept some type of self-aware computer as alive, then we'd have to tweak the definition, such as it is, and then we're no longer talking about "life" as we think of the word today.
I guess people often wonder about other biochemistries. As far as I know, from a semester of undergrad astrobiology, we don't currently consider those very likely. Silicate chemistries were speculated for decades, but the chemical dynamics just don't tend to work out. The other main idea was ammonia as solvent, but that'd be hardly exotic, and the current thinking is that biochemistry would be entirely too slow at the temperatures where ammonia is liquid.
The wilder ideas, like high energy chemistries on the surface of neutron stars only ever appear in science fiction. (Excepting the odd paper from the seventies, but that was a strange time.)
Maybe people will accuse me of a lack of imagination, but I think it's telling that these threads are almost always mainly the home of comments shouting the word "quantum" like it means something, or getting their information from Mass Effect.
I do think it's an interesting question whether we'd be able to recognize other types of intelligence, but I am pretty sure we'd be able to recognize other types of life.
(By the way, the article seems to be mostly about whether we'd recognize alien life seen through a telescope, but that hasn't deterred speculation about other kinds of life in the thread.)
Source: I actually studied this in college, for a bit.
> We don't even really have an agreed-upon definition of life, so the question is basically non-sensical.
...
> I am pretty sure we'd be able to recognize other types of life.
...
> Source: I actually studied this in college, for a bit.
So, let me summarize. You find the question non-sensical, then you are sure you know the answer, and finally you appeal to authority (your own) to elevate your opinion over those of us mere common-sense mortals.
Sorry, I'd have liked to give more weight to your angle, but you kinda made that hard.
Yeah, I didn't express myself very clearly, sorry.
Let me try again: I think our various definitions of life are not the actual definition that most astronomers have in their head. I think the actual definition people believe is "I know it when I see it." Two illustrative examples:
Let's say we find a system of chemical reactions going on somewhere that meets most definitions: self-regulating, initial chemical seeds as a basis for heredity, some chain of triggers that causes it to look like it's responding to a stimulus.... This is isn't far-fetched, reactions like this exist in a lab. I don't think we'd call that thing alive - we don't currently. There would be arguments, but most people would probably agree it's a technicality.
Now let's say we find something totally way out there crazy from a science fiction book, like a naturally occurring "computer" running an alien civilization on it. It doesn't have homeostasis - would we call it alive? Most people probably would.
I guess I am prposing that the prevailing actual definition of life that lives in our heads is probably closer to "would I feel bad about killing it?" By both this and the more technical definition, we'd almost certainly recognize it, at least when studied up close. (But probably not through a telescope.)
Is that more sensible?
> you appeal to authority (your own) to elevate your opinion over those of us mere common-sense mortals.
I mean, I'm actually kind of arguing in favor of a common-sense definition, and it's a comment on the internet, which would take me three times as long to type if I sourced it. I would do that for a blog post, but I don't even know if anyone is going to read this :)
But, in fact, this is all so abstract that I wouldn't know what to cite. I still think having an idea of biochemistries, the energy scales, etc. makes someone in the field more qualified to speculate than completely uninformed internet comments.
>We don't even really have an agreed-upon definition of life, so the question is basically non-sensical.
I disagree. The most common definition used by working astrobiologists goes along the line of "chemical system that can self-sustain and can undergo darwinian evolution". Our definition of life is intricately tied with our theories about life's origins, and the counter-examples to that definition are fictional and their premise falls apart on closer examination.
Let's take the self-aware computer you mentioned. How would such a computer come to being, exactly? It could have been built by something that does satisfy the above definition (in which case you could consider the computer not alive, but a biosignature). Or it could have been built through some darwinian process, and you're still firmly within the above definition.
Steve Benner has a nice paper about this. DOI: 10.1089/ast.2010.0524
The article doesn't actually address the problems with the 'evolutionary definition', probably because it would mean trying to chip away at a theory that a lot of people spent a lot of time trying to disprove.
> Alive are the things we say are alive, which is mostly stuff like us: some type of metabolism, growth, response to stimuli. By that definition we would certainly recognize it, at least up close.
I don't think I expressed myself very clearly, but I actually agree with you on most counts. The definition you listed is also the one I mentioned + evolution.
> What about fire?
I actually rambled about fire, and then deleted the paragraph because the comment was already all over the place. Fire, to me, is a good example of the "good definition" problem I mentioned. I guess we'd all agree it doesn't respond to stimuli, and a necessary property of having a metabolism would be some kind of homeostasis. It also doesn't undergo evolution.
But rejecting it on those grounds doesn't feel complete. Let's say we find some chemical reaction that does self-regulate. This exists in a lab or computer modeling (e.g. https://doi.org/10.1073/pnas.2022987118). Let's say its properties are determined by some initial chemical markers: a basis for heredity. Would we now call it alive?
I don't think we would. I think our definition of life is "I know it when I see it" and the more formal definitions we've tried on in astrobiology are basically just retrofitted to the examples we know or can think of.
> we don't even really have an agreed-upon definition of life
Regulated metabolism. Homeostasis. I think that's close to capturing the idea we're after. A self-aware computer still has to store its bits somewhere, and get energy and material to do that, presuming it wants to stay alive. That process might as well be called metabolism. Unless it is just totally alien (heh) physics, there would be some kind of metabolism, and localized regions which create an environment suitable for that metabolism to place. That would, if nothing else, produce heat and unusual compounds.
Are viruses alive? They aren't commonly considered to be. They don't have a regulated metabolism without parasitising on the cells of other organisms.
But then again, I doubt humans would have homeostasis for long without their microflora. How is that different? Isn't a virus just a more extreme case of symbiosis? What about less extreme obligate parasites?
Life defies categorization. At best you can find common markers (in addition to the ones you've mentioned, the traits required for natural selection to occur - i.e. reproduction, variation in trait, and variance in offspring - may also be of interest), but in the end it boils down to the anthropocentric notion of "things like us", which isn't very useful outside earth.
It's possible a life-like system might have parts that, on their own, don't seem like-life. Human economic activity would fall under the category of "metabolism" that I used, for example. Cars are not alive either; but they, are, in the loosest sense, part of a living system. Fossil fuels for shipping food around are a part of the larger system of metabolism, ultimately enabling viruses to replicate in their human hosts. Viruses are dependent on metabolism, too; even if they can't do it themselves.
This was a good write up as it contained criteria and points for "defining life", it was nice to have a refresher on the meaning of "entropic" life as well.
I've often thought if complex extraterrestrial beings were discovered they may not "look" much different than anything found on earth, since the spectrum is so vast on this planet (bacteria, plants, mammals, cephalopods, etc.) - considering the universal confines of physics and locomotion.
Isn't there something special about crab/spider anatomy as well and it being very "evolutionarily stable" or something? Cannot recall any papers or information on specifics here at the moment.
Meanwhile, I always laugh watching old Twilight Zone episodes and how they have regular humans playing aliens - they don't even bother to differentiate them as a species (likely because of available technology) but think this can work well in a way.
He talks about why certain things simply make sense. Like how wings evolved six times, why communication via sound is simple and communication via some sort of telepathy is not, and why it makes sense for a large animal to be symmetric. From that he reasons why alien life probably wouldn't look all that different.
Communication through sound is just vibrating your inner organs at a pattern of frequencies, causing the air to vibrate at the same frequency, and resulting in someone else's ear drums vibrating at the same frequency. This causes thoughts to spontaneously appear in your partner's head. How is this different from telepathy?
The takeaway is not how speaking is like telepathy, but that telepathy wouldn't be that different than speaking. It would presumably have some different characteristics, like speed-of-light propagation, but it would still be just a sense organ.
"Dammit, Joe's thinking at me again. I'm going to ignore him while I watch TV."
Who is to say that is a universal phenomenon? May have something to do with our level of gravity, life cycle of the blastocyst, metabolic requirements from respiration, other fauna competition, etc. Which is not to say there is a better alternative on the table, but I would hesitate to say that we should expect crabs on other planets.
Edit: Kicking myself over the missed opportunity to say "space crabs" or a Zoidberg reference
The fact that there are a large number of crab-like land and water dwelling organisms, and in a range of sizes and regions, suggests there's a pretty big range of environments that crabs thrive in. That's still far from universal, but it's also not very limited either.
Earth has been through similar changes too. Life started in water, a "low gravity" environment, then moved onto land. Similarly, the atmosphere was initially very oxygen saturated, causing animals to be very big. Declining oxygen rates in the atmosphere caused animals to converge to a smaller size. But, we don't see extreme differences when you compare animals from millions of years ago to today despite that the ecological parameters have changed significantly.
But those are all coming from the same progenitor life form. Initially selected components are relatively fixed from that point onwards. For example, mitochondria having their own genome and replication machinery feels like a poor solution, but it is "technical debt" that can never be corrected. A different set of circumstances could have favored all organisms having skeletons instead of exoskeletons, a singular orifice for ingestion and excretion, etc.
The existence even of mitochondria is insane though. A cell happened to eat another cell and instead of just digesting it, the prey cell fused with the predator and became mitochondria. Bananas. Similar story with plant cells.
The spectrum on this planet really isn't all that vast. Sure, to you looking at an organism's morphology it looks vastly different, but so do dog breeds from eachother yet they are all dogs. You have a lot in common with all forms of life in terms of how your cell biology works, because we all share a common ancestor.
Life on another planet might originate from an ancestor that functions dramatically different than the last common ancestor for all life on Earth, and that might have huge implications for what a potential multicellular organism with this evolutionary trajectory would look like (if such life even utilized multicellularity, or cells at all)
Remember when most of the known exoplanets were hot Jupiter-like worlds, so it looked for a moment that perhaps those were the dominant type of planet, but then it became clear that this type of planet was commonly detected just because they were the only type of planet our techniques were capable of detecting?
Same, but for life. We’re probably only going to find the kind of life that has the characteristics and behaviors that we currently recognize as life, and is in a place we think of pointing our telescopes at, and our telescopes are a fine enough sieve to see.
At some point, if you stretch the definition of life too far, what's the point? Like, what's the point of saying a rock is alive? We've got them everywhere, we know they exist everywhere but we can't really do anything with that info.
Knowing something is alive gives us a basis for interacting with it. Saying we found life on Mars isn't important because we found life there. It's important because it challenges or confirms our expectations about so many other things.
It's kind of like shooting hoops. The hoop stays in the same place and we try and throw the ball into it from different angles. Each angle we can throw it in from teaches us something new. If you took that hoop and just decided that you get a point by moving the hoop to the ball instead, what does that actually help us with?
Another way of saying it. If everyone is a superhero, then nobody is.
Disappointed to see there is no mention of Lem's Solaris, whose devoted large paragraphs to this very question.
For a very enlightening, very poetic short story from a little known author, I would encourage sci-fi fans to search for "La porcelaine de l'univers" from Bruno Vizerie.
One interesting research group tackling this question is ex-computer engineer, currently biologist Prof. Micahel Levine's group.
They built xenobots (biological robots) from frog cells which are not evolutionarily programmed to do tasks which they accomplished. Their research in part deals with emergence of agency at multi-cellular level. And they want to get at the fundamental signatures of what makes some collection of agents into a new single agent at an higher level.
When I got my teaching credential, I had to take a biology class because I hadn’t taken any biology as an undergrad (I also had to take government and P.E. as well for the same reason—having aced the AP American History exam 17 years earlier in high school spared me from having to take an American History class). One of the things that sticks with me still is the somewhat inevitability about the formation of cell membranes given the characteristics of the atoms that compose the molecules that compose the membrane. I was left thinking that life like as we know it on earth might, in fact, be very much a likely outcome of any planet of suitable size, location and composition.
Nowhere in nature (that we know of) does any organism make a membrane from scratch. All membranes are extended from an existing membrane, and then pinched off. Possibly, all life and all its existing membranes were extended from a primordial membrane.
Arguably, DNA, RNA, and the proteinome are just the universal membrane's way of making more membrane more efficiently.
I’m surprised there isn’t more discussion of life as a kind of information processing. This would put life on a spectrum from viruses (very little or arguably no intrinsic information processing) to humans, which can process even abstract information. But it would also include the kind of life we might potentially find in Jupiter’s clouds, or in the layers of the sun.
Discussing life in terms of Darwinian evolution or chemical complexity seems to miss the point. I’d be happy to consider an AI or a cloud “alive”, even if (like a virus) it requires help to replicate.
But we are... the product of code, read by machines, processing input to produce decisions.
How are not information processors ? Do you think computers are not a natural extension of us ?
There is absolutely discussion of life as information processing, for instance Stanislas Dehaene is super interesting but I ve heard conferences in biochemistry explaining why all amino acid would work to code information, but the 4 DNA uses have chemical properties that help persist and clone it better and the like.
Sorry, I meant that the article doesn’t talk about life as information processing. Perhaps I should have said, “I’m surprised there wasn’t”. Although I got about ¾ of the way through it so maybe I missed it. But at the time of posting, nothing in these threads either.
I firmly believe that life on Earth was triggered by spores meeting water and developing mycelium networks breaking down minerals into nutrients and slowly taking advantage of photosynthesis to develop more complex life forms. Spores can easily resist the vacuum of space, and pass any form of great filter. They do help create enzymes and uptake nutrients, they do help break down minerals, they do communicate with entire ecosystems, and so much more we barely understand. This would mean that fungi are of alien origin.
Are you suggesting that these eucaryote spores were the only source of life on earth? That would require them to have evolved into procaryotes which seems unlikely. It also doesn't really solve the question of how the alien life arose in the first place, so it lacks explanatory power.
This is actually a fairly reasonable theory given the information we currently have access to - not "spores" per se but rather by amino acids entering our atmosphere. Check out the "panspermia theory" as well as the "Murchison meteorite", I believe there may have been amino acids found on other meteorite samples since and perhaps one within the past 5 years or so.
It's possible though our planet is very "ripe" for harboring life and there are multiple avenues through which it has evolved over time.
What advantage does this theory have over the more common (?) assumption that the amino acids came to existence on earth itself? Serious question, I'd like to know.
For example, this theory sti doesn't answer the question how they came into existence in the first place. It's certainly not obviously better than assuming they suddenly appeared on another planet and then transported to earth..
>For example, this theory sti doesn't answer the question how they came into existence in the first place. It's certainly not obviously better than assuming they suddenly appeared on another planet and then transported to earth..
Not sure what you're getting at WRT amino acids. Amino acids form due to the particular chemistry of carbon (what we call "organic chemistry"[1]), and they do so wherever both energy and the building blocks of amino acids exist. No planet required.
This was shown pretty well by the Miller-Urey experiments[2] as well as the discovery of amino acids in interstellar molecular clouds[0].
So...Amino acids can (and do) form wherever the raw materials and energy exist. That's the "how".
planet is an amalgam of rocks and minerals, heat is provided by the sun, water could have been of extraterrestrial origin, and then enters fungi using heat and humidity to develop mycelium, mycelium turns minerals into compost with enzymes, space dust introduces bacteria which evolves through thermal vents a/biogenesis, and voila, you have life. We do know that before vegetation, Earth had fungi structures made of half rock, half fungi flesh, and they probably evolved into actual trees. At the same time, lichen spread from underwater to the surface of the Earth. Fungi released CO2, creating an atmosphere for plants to develop. The rest is evolution.
I'm not so sure it offers an "advantage" but it's rather just something we seem to have evidence for - indeed it does not answer any questions rather raising more possibly
It doesn't though. It only requires for life to have evolved on another planet, reached space and then potentially traveled lightyears through space to reach earth.
Space is really fucking empty. Seems less likely than throwing a rock out of a rocket on the way to mars and hitting a random bucket, without looking. Add to that that it would require life having evolved while the universe was younger and different to the only state of the universe that we know to support life.
Is it impossible. No. But at that point the theory has as much explanatory power as creationism, i.e. none.
This made me laugh, yes I agree in a way. Maybe some day we will discover amino acid constituents on earth or another planet and it will fill in more of the blanks. It's the definition of chicken and egg though
Thanks for the link and for the reminder, did learn about this experiment actually in organic chemistry years ago. Suppose it's a bit nonsensical to look for amino acid "constituents" then. Not a fan of the snark though
The interesting implication of panspermia is that is yes, we would recognize alien life. I find this optimistic. Anthropocentric perhaps? Like a version of living in a slightly more sophisticated sci-fi show.
Thats assuming there is one single common origin for all panspermia. There could be multiple events and independent lineages. These are not mutually exclusive hypothesis because even with panspermia, life would have to originate somewhere to be seeded elsewhere.
Is your belief based on any kind of evidence in which case I'd love to hear your best arguments, or is it a religios belief (like in Jesus) in which case there is not much to discuss?
Sure. But stating a belief without any reason why this would be true, or more precisely, why this hypothesis would be preferable over the currently accepted hypothesis which does have supporting evidence, is just not very convincing.
Says who? They do present properties of thinkers when they regulated entire ecosystems via their networks of mycelium. They even communicated with micro electric impulses. Start thinking outside of the box, not within boundaries of definitions.
What we consider life are just mechanisms that are complex enough to feel mysterious, also grow and develop fast enough for us to notice.
I don't think looking for life makes much sense. Looking for intelligence (anything you can communicate with to reach meaningful results, insects are also intelligent, pocket calculators also are and that would be cool if they had emerged without the humans building them) and consciousness (no good definition existing to the date) is what is interesting.
For every Boltzmann brain that doesn't know it is one, an infinite number do know, and are horrified. Another infinite number of them are not. Yet, there are an equal number of all three.
Not only would we likely not recognize it, we are probably staring at one or more forms of life right now that we are failing to recognize. Likewise, sentience in them or even in the familiar form.
As a hot take I’m not incentivized to respond seriously, but I will say that Carbon-based life as we know it on Earth is seriously antifragile. We’ve found life in the most inhospitable places we can imagine and the kicker is it’s all self-replicating and self-healing.
Yes, we’re meat sacks that pop when poked — that’s a very conserved trait of life on Earth — but for the most part, especially with a holistic view like at a species level, we’re ridiculously hardy.
> We’ve found life in the most inhospitable places we can imagine
...on Earth. Take away something as simple as the magnetic field of the planet and suddenly resilient life narrows down to a couple of bacteria, Archaea, or Tardigrades [0] which still die with enough exposure.
Anything above 120 degrees C will also cook our goose and every other form of life, again short of a few Archaea [1] which still die a few degrees later.
And then there's the most basic of all: water without which some life doesn't die but doesn't exactly "live" either. A handful of spores, spore-like forms, or completely dried forms of bacteria for example can go for eons without water but they're not functioning.
And the higher level and complex the organism (thus possibly easier to recognize as life), the higher the chances one of the "subsystems" is more fragile and its failure kills the organism.
I don't think life can be evaluated as a snapshot in a moment of time. Life is a process, and it affects a population. I think even the most conservative definitions may agree on that.
Antifragility plays well with this definition: it doesn't describe the state, but the potential and the ability to change. Taking into account the huge populations, and the fact that only a couple individuals must survive hardship in order for life to prevail, I can see the antifragility.
That "we can imagine" is doing a lot of the work, there. We humans are pretty limited in experience, operating parameters and yes, imagination. On but one dimension, consider the range of all possible temperatures and how narrow the band in which the lifeforms of which we have knowledge can survive. Consider the same along all other dimensions like radiation, gravity, pressure, particulate density, magnetic field intensity, perhaps others we have not even discovered yet.
Carbon life that we know about is "robust" only considering the relatively narrow ranges on our own planet.
The range of all possible temperatures is theoretically infinite. Life as we know it — without protection — can survive at everything from 0K to 386K (113C). As humans we have harnessed temperatures in the 100s of millions of degrees (fusion) safely and can build machines that reliably extend our operating parameters far beyond their normal bounds.
It’s easy to be dismissive, but the reality is that life as we know it is pretty freaking incredible.
enkid's people have had a remote outpost near the center for some time now. They have not reported finding any life so far there but can we really trust them after the Saturn 3 disaster?
I actually agree with 'QM/EM based life'. My current thinking goes as following..
- Intelligent life develops superfast AI
- - then develops even more advanced quantum version of it.
- Life slowly starts augmenting its meatspace with advanced replicable machinery
- Eventually everything starts becoming very predictable so it start absorbing the advanced AI in our minds, which slowly becomes our essence (assuming consciousness is 'computable' ie.. not some penrose-esq orchestrated reduction)
- It then builds a hypercomputer operating at very close to max efficiency and start harvesting all matter/stars to sustain it & migrates to it.
there is another path where just like light currently exists as an EM wave packet we discover other stable forms and migrate to that.
of course this does not means the pervious iterations of life do not continue to exist, just that they become increasingly irrelevant.
Actually a valid theory that angels are just friendly aliens and demons are the bad ones. If they can visit earth they probably have godlike technology.
I think there was an episode of the Outer Limits like this where some scientist made contact via wormhole with aliens and they looked suspiciously like demons with the horns and everything. The aliens of course said “we have a bad rep but we’re actually good guys!”, then proceeded to do something like drain the oceans or boil them for terraforming or something apocalyptic after convincing the scientist to let them teleport through.
(I've probably been reading too much sci-fi.)
Alien life does not need to be restricted to matter as we know it; if space itself can give rise to self replicating structures, then it too could be alive.
Beyond that, life could occur in any medium and at any scale (in either space or time).
Even regarding terrestrial life, how long did it take for us to notice microbes (as something other than a curse from god)?
There could even be macroscopic lifeforms moving so quickly that we are unable to see them.
So the answer, as far as I can tell, is really that it depends on the kind of life we're referring too.
And if it's too far outside the human context of understanding or perception, then the answer is no.