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Comment by lachlan_gray | Hacker News Reader

It's fascinating to me that the complexity of life always goes up. Outside extinction events, complex life generally seems to become more favourable over time. It's interesting that (to my knowledge) we don't see an ecosystem lose complexity in its entirety unless it's dying.

Simple organisms make a bedrock for complex organisms, and while the complex organisms have more specific needs, they are better at exploring, gaining, branching out. So they also kind of make a nest for the simple organisms by sprawling into the void and finding habitable niches that simple organisms wouldn't reach on their own.

On the time scale of technology, we began reaching out to other intelligences the second that we could, began trying to make them the second we thought we could know how. It's very reasonable to say that percolation is a defining property of life and intelligence.

I also think a lot of scifi's like hyperion, neuromancer, foundation. In human writing of the future, it seems like the endgame of higher intelligence is to find or create other intelligences, and get closer to them. Then interesting things happen in the wake of that.

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Check out the work of Ilya Prigogine - he won a Nobel prize in the 70's for his work on self-organizing complexity. There is a selection force in the universe for increasing complexity, being driven by the dissipation of energy. When you have systems in non-equilibrium, there is a strong pressure to explore the possibility space to find ever more efficient ways to dissipate energy.

A bacteria the size of a grain of sand dissipates much, much more energy than the grain of sand, and so there is a very strong "preference" for bacteria in this regard.

Is there already a theory for life->greater complexity similar to that of entropy in physics? It seems just as inexorable.

The theory is that they are one in the same, or better to say that entropy is the process that drives life. In that, life grows in complexity in order to dissipate heat (i.e., increase entropy) more efficiently.

Just look at Earth. Life is incredibly complex but is ultimately driving everything towards dust.

>life grows in complexity in order to dissipate heat

This seems silly on the level of the anthropic principle.

It's like claiming a calculator exists to use up electricity.

We're eddies in the flow of energy from high to low entropy because it's free energy.

We create more entropy in capturing energy than we capture because it's impossible not to.

There's no purpose for life there. It's just where life lives.

> It's like claiming a calculator exists to use up electricity.

sighs in bitcoin

There is a minor pedantic point to make that akshually heat dissipation carves channels of energy flow that look to us like life rather than the causality going in the other direction.

> entropy is the process that drives life

Depending on how you look at it, life is driven by the opposite of entropy. Schrödinger in his book, What is Life?, calls it "negative entropy" or even "free energy".

> In the 1944 book What is Life?, Austrian physicist Erwin Schrödinger, who in 1933 had won the Nobel Prize in Physics, theorized that life – contrary to the general tendency dictated by the second law of thermodynamics, which states that the entropy of an isolated system tends to increase – decreases or keeps constant its entropy by feeding on negative entropy.

> The problem of organization in living systems increasing despite the second law is known as the Schrödinger paradox. This, Schrödinger argues, is what differentiates life from other forms of the organization of matter.

> Schrödinger asked the question: "How does the living organism avoid decay?" The obvious answer is: "By eating, drinking, breathing and (in the case of plants) assimilating." While energy from nutrients is necessary to sustain an organism's order, Schrödinger also presciently postulated the existence of other molecules equally necessary for creating the order observed in living organisms:

> "An organism's astonishing gift of concentrating a stream of order on itself and thus escaping the decay into atomic chaos – of drinking orderliness from a suitable environment – seems to be connected with the presence of the aperiodic solids..." We now know that this "aperiodic" crystal is DNA, and that its irregular arrangement is a form of information.

https://en.wikipedia.org/wiki/Entropy_and_life#Negative_entr...

I don't think you understand my point or what Schrodinger wrote. The Wikipedia synopsis of Schrodinger is unlikely to be accurate.

https://www.quantamagazine.org/a-new-thermodynamics-theory-o...

https://www.bbvaopenmind.com/en/science/leading-figures/ilya...

Thank you, I'm familiar with the work of Ilya Prigogine, and the first linked article is one of my favorites that I've read several times. The relationship between life and entropy is a fascinating topic for sure.

It seems we've talked at each other then, haha.

Oh I didn't notice you were getting downvoted up there in the parent comment, it wasn't me! :)

Anyway, I'm now going back to read Prigogine's book, Order Out of Chaos. It's also brought me around to think and study more about self-organization and emergent properties of complex systems.

About "A New Physics Theory of Life", and the idea that life exists because "the law of increasing entropy drives matter to acquire lifelike physical properties".. I see this is what you meant by "entropy is the process that drives life".

> Besides self-replication, greater structural organization is another means by which strongly driven systems ramp up their ability to dissipate energy. Thus, England argues that under certain conditions, matter will spontaneously self-organize.

Re-reading the article, I'm struck by how entropy and organization are, seemingly paradoxically, two sides of the same coin. It feels like there's something profound there, some principle that explains many phenomena at different scales all at once.

You might really like the short book What is Life? by Schrödinger, it delves into exactly that.

The Sun outputs 3.9 x 10^26W, but it weighs ~10^30kg, so that would mean 10^-4W/kg.

Human beings are closer to 1W/kg at rest.

Now do a lump of plutonium.

How did that lump of plutonium become a lump? That part wasn’t natural.

Life is a great entropy accelerator.

compared to a black hole though?

It might be too soon to tell. We might start creating them ourselves.

"How did that lump of plutonium become a lump? That part wasn’t natural."

Allow me to become a little philosophical but since human beings which are product of nature made plutonium, isn't the making of plutonium natural too?

I mean everything that is happening in this universe is natural!

I know the general usage of the words "artificial" for human-made and "natural" for everything else. But when we are talking at the grand scale of life and universe I think a human-made plutonium is as natural as bee-made honey.

Perhaps a better phrase to have used would have been "not prior to a complex system" -- as the lump of plutonium exists only because of a complex system doing its thing, it should be considered a consequence of the complex system rather than an alternative.

To attempt to pedantically clarify, is "exists only because of a complex system doing its thing" not true of basically any pure lump of material that exists?

To me, the actions of stars fusing heavy atoms and then those atoms ending up in lumps of material somewhere sounds like a pretty complex system doing its thing.

I love debating this with people but ultimately it's just playing games with semantics. The notion of artificial x natural is very recent and very localized. Some cultures would differentiate raw from cooked in a similar sense. But it's like talking about what is really green vs what is really blue. Completely circular since it depends on the definitions of the terms.

It's easily extendable to the animal world as well. Is a nest created by a bird or a den created by one of various mammals natural or artificial? Is a nest made by mice in my garage from synthetic fabrics, flexible plastics, and whatever plant matter it can find natural or synthetic?

My wife was recently asked to make a meal for someone who didn't eat "processed" foods. What level of manipulation needs to happen before a food is "processed"? Can beans or rice be dried and put in a bag? Can chicken broth be used if it's homemade, but the chicken came from a commercial farm? Or is extracting broth from a chicken processing it?

I've increasingly noticed many sub-cultures adopting odd definitions and interpretations of commonly used language with the expectation that everyone who interacts with their group understand their dialects. It's not really jargon or vernacular since the words are common to the language, just used to mean something different than the general population would understand. Similarly, artificial is now assumed to mean bad and natural good, when neither ascribe value by definition or in practice.

You could approach the language problem like that as well. Before imperial efforts in recent centuries to normalize languages in certain territories, there was no Standard French or German or Italian. Vocabulary and accents changed slowly across the landscape, following geography - places isolated diverged and places integrated converged. Migration, trade and conquest added layers of complexity to this variation.

But your idea that people are failing to use Standard English and creating language subcultures around peculiar meanings of artificial/processed/chemical vs natural/homemade/organic is itself based on a very artificial distribution of language.

Which isotope? It makes quite a difference, and there's no "naturally occurring" with Pu.

Wow, that's a great way of describing this! Definitely noted for future use.

Really brings up the difference between the energy density of the fusion reaction and the energy density of fusion plus the confinement system to enable the reaction!

Hmm, then the challenge is to find a more efficient confinement for a fusion reaction.

This is enlightening. Has anyone posted some kind of comparison table somewhere?

The sun's power density is approximately the same as compost.

Can you elaborate on that or drop a link that explains more?

Live/fresh compost creates heat as a byproduct of cellular metabolism during decomposition. I assume this is is using thermal output of this compost as a measure of energy.

What more do you want to know.

The rate of fusion in the Suns core is actually very slow and gram for gram it is not producing much energy. But the core of the Sun is well insulated by the vast bulk of itself, so even a slow release of energy builds up to extreme temperatures.

https://en.wikipedia.org/wiki/Sun#Structure_and_fusion

Here's a decent stackexchange discussion: https://physics.stackexchange.com/questions/370899/suns-powe...

So does that mean that making a fusion reactor makes as much sense as building a containment vessel for a compost reactor?

Stars have to have enough mass to have enough gravity to start and sustain a nuclear reaction that constantly blasts energy out in all directions. This limits just how energy-dense they can get. What they lack there, they make up for in size and lifespan.

We can make sustained nuclear reactions in much less space using engineered pressure instead of gravity, so that skews the energy density ratio.

The Sun uses gravity, due to its mass, for fusion containment. Fusion reactors on Earth use electromagnetic containment.

Fusion only happens in the Sun due to incredibly rare quantum tunnelling events. That is why the sun can burn for billions of years. It takes a long time for the energy generated to reach the surface and escape, that is why the sun has a high temperature.

IIRC fusion reactors on earth use magnetic confinement to raise the temperature much higher than the sun's interior for a much higher rate of fusion reactions. I'm sure someone will be along to correct me if I got that wrong. ;0)

The average American also outputs about 125W/kg if you include our technology, and not metabolism.

US Primary energy consumption = 30 Trillion Kwh/ year [1]

30 Trillion Kwh/ year / 8760 hrs = 3.3×10^12 W (watts)

3.3×10^12 W (watts)/ 330million = 10 kW/ person

10 kW/ person / 80kg = 125 W/kg

https://www.eia.gov/energyexplained/us-energy-facts/

So we really are batteries for the Matrix.

Joking aside, this comparison is really beautiful.

So we're all agents of Entropy, spinning our circles until we die all in the service of heat death? I don't like it!

As someone said about thermodynamics: You can't win, you can't break even, and you must play the game. (Source unknown)

I don't understand this view at all. We are what we are. Entropy is a concept in our mind and heat death is a very particular phenomenon that depends on the systems experiencing it being very specifically defined in ways that the Universe cannot be.

We are. Descartes had the right idea. The experience of consciousness is irreducible. To say "we are atoms thinking" and variations thereof is utterly meaningless. All words and concepts used for such word play is dependent on the experience of human consciousness. They don't exist independently. Consciousness is the only thing we can posit that has independent existence. Everything else is just a concept created by a conscious being.

It's like the tree falling in the forest with no one to hear it. A universe without consciousness experiencing it really exists? Existence is a property of consciousness. We can't conceive of things that are not experienced, by definition. Even if we imagine a dead universe with just energy and no consciousness, that is an image that exists inside of a conscious mind.

> Existence is a property of consciousness.

Kant would vehemently disagree. Not that I'm a Kantian, but he makes some pretty good points. So I think there's a lot of work here that needs to be done to make your argument stronger.

I'm not into winning debates. I just find interesting that conscious beings think they can imagine the absence of consciousness. For us consciousness is the fundamental reality.

Furthermore I find the verbosity of German philosophy nearly unbearable, to be honest.

You say: "We can't conceive of things that are not experienced, by definition"

I mean, you probably don't even realize that this view is influenced by Kant. You are giving a very poor retread of 200+ year old German idealism.

For example, from the Wikipedia article on Critique of Pure Reason [1], Kant's major work: In the preface to the first edition, Kant explains that by a "critique of pure reason" he means a critique "of the faculty of reason in general, in respect of all knowledge after which it may strive independently of all experience"

I think it is fair to criticize his prose but it isn't like you don't have access to well over 200 years of commentary and follow-ups to one of the most famous and important philosophers within the Western tradition. For a gentle introduction I suggest this video [2] (42 minutes) where Geoffrey Warnock (at the time the Vice Chancellor at Oxford) provides an overview of Kant's ideas.

It is also fair to disagree with Kant, but it is pretty obvious when you are talking about the subject he dominates while having no experience with his work. The reason he is so famous is that he had very compelling things to say on this very subject.

1. https://en.wikipedia.org/wiki/Critique_of_Pure_Reason

2. https://www.youtube.com/watch?v=wlEMkAkGS1I

It's a fairly narrow view if you think I shouldn't philosophize unless I conform in full to all YOU have read.

I'm not telling you what you should or shouldn't do. I'm pointing out a few facts including that your viewpoint is well over 200 years old, that specifically Kant addressed it and influenced the entire discussion around it, that it is clear you haven't considered his or any other philosophers rebuttal to it.

To give an example, it would be like you were talking about gravity and saying that Newton was right. Then someone mentions Einstein, and you respond that you couldn't be bothered understanding the general theory of relativity because the math is too hard.

I mean, no one is saying you should read Einstein, just that Einstein had some things to add to the ideas of gravity that are worth considering. And if you want any theory of gravity that you have baked up on your own to be taken seriously, you will find that others will expect you to show some familiarity with his theories. And further, there is a wealth of material on his theories that does not require you to engage directly with the esoteric math.

The same is true about Kant (although, to be fair this is philosophy and not physics, so he didn't supplant Descartes in the same way Einstein did Newton). He added explicitly to the question about the bounds of knowledge with respect to experience. So if you are making claims about that subject then it is not unreasonable to expect that you have at least some familiarity with his contribution.

> So I think there's a lot of work here that needs to be done to make your argument stronger.

> You are giving a very poor retread of 200+ year old German idealism.

You kept putting me down because my ideas don't jibe with your readings. Now you're comparing philosophy with physics.

I am trying stay away from such pedantic bibliographic review. You keep appealing to authority to minimize my contributions. This is why I didn't want to go down this road. Thanks for dragging me.

> your viewpoint is well over 200 years old

Hate to break this to you but the ideas I'm talking about are well over 3000 years old. Kant et al are a cul de sac in this tradition.

> Kant et al are a cul de sac in this tradition.

Perhaps, yet how would you know if you refuse to engage with it?

I'm not sure how to respond when someone insists on remaining ignorant of alternative viewpoints and then suggests that any attempt to point out relevant arguments against their position is victimizing them.

So refusing to engage with you and your readings is refusing to engage at all with the subject and insisting on ignorance?

I saw the self importance a mile away and I said I wanted none of it. Like I said, I dislike German philosophers verbosity and I'm getting to dislike its fans' self importance.

edit: you've called my ideas half baked, you've called me ignorant. it's pretty clear to me now you just wanted to play vocabulary ping pong with dead man's ideas to feel smart. I pretty much intuited it, and regretted every engagement with you so far.

> Not that I'm a Kantian, but he makes some pretty good points

It is even debatable what points he really made. As always in philosophy.

I'd say that existence not being a predicate of any object is kind of non-debatable :)

It is, actually. Kant differentiates between "real predicates" and "logical predicates", and only states that existence doesn't belong to the first category, because it "doesn't enhance the concept". The whole distinction is quite unclear, and Kant's claims can be interpreted in multiple ways, as people do in some publications.

Actually this famous slogan that "existence is not a predicate" is closer to proposals of Russell and Quine.

Disclaimer: quoted phrases from Kant may not match exactly what you can find in English translations. I know Kant from Polish translations, so I improvised a bit.

> A universe without consciousness experiencing it really exists?

As long as we don't discover something truly novel this is how reality of this universe looked like before we came since its creation. And it fared just fine.

> since its creation

Interesting turn of phrase about a supposed reality deprived of consciousness. Created.

That is mind blowing! It reminds me of Conway and Wolfram's automata theories although perhaps those models did not emphasize the energy aspect of it.

Very interesting. Do you have an intuition for why there is selection pressure towards energy dissipation?

My current intuition goes something like this:

Energy MUST flow. No matter how energy is captured and stored, there is a pressure for it to continue moving.

The movement of energy means that matter is always moving, and new configurations are always being "discovered."

Some configurations allow for energy to flow more easily, and when one of those configurations is "discovered" the movement of energy keeps that configuration in place. I think it's literally a strange attractor from chaos theory.

Areas of stable energy flow create correlations across space time that allow for more complex correlations to emerge.

Here’s an interesting network-focused view as to why that might be: https://royalsocietypublishing.org/doi/10.1098/rspb.2012.286...

Sorry if this question is answered elsewhere in this post's replies, but would you say that matter can be viewed as 'captured' energy, or energy at rest?

> matter can be viewed as 'captured' energy, or energy at rest?

No, matter isn't 'captured' energy any more than it's 'captured' mass or momentum. Energy is a quantity, not a substance.

Energy is a behavior, or alternatively a probability.

Tweak your intuition: energy IS motion. When things are not moving, there is no energy. When there is energy, things are moving.

Then energy is relative? An object is 'stationary' in space, a comet comes along and hits it. The comet has energy.

OR the comet is just sitting there, 'stationary', the object hits it. Not the object has energy.

There's no total energy to a system, except calculated from some point of view?

energy is a term we use that describes the probability for some unit of matter to be in a different state at time T' than it was at time T.

if you consider the state to include position - relative to a frame of view - then energy describes (at least in part) the likelihood that the position at time T' is different than at time T

How would you describe a rock sitting on the top of a mountain? It is not moving relative to the matter around it, but it certainly contains quite a bit of energy, in a variety of different forms.

I am trying to recognize that even in that rock, energy is dissipating in multiple ways, and any number of different events can lead to it dissipating in different ways.

I suppose you can say that the individual atoms composing the rock are moving, but are those movements connected to the potential energy it has by virtue of being far from the relative minimum in a gravity well?

That rock could fall down the mountain mostly intact - a highly energetic event, compared to being eroded away chemically by rain over millennia.

potential energy is. IMO, largely a pedagogical tool. it's an explanatory position, rather than a thing.

the rock, does, obviously "contain" energy thanks to e=mc2. but the notion that the rock is energetically in a different state as it sits on top of the mountain that when it sits at the bottom never sat well with me in high school, and it still doesn't, 45 years later.

It takes energy to move a rock to the top of a mountain, and you can get some of that energy back (minus friction etc) if you let it roll down. So it's got something.

I mean any type of energy is just as intangible as potential energy, so I don't see that the energy stored by doing work (i.e. interacting with one four forces) is that different to the idea of energy stored by being in motion. You never measure "energy" directly after all, but it's a useful abstraction - after all, everything in science is an explanatory position.

Yes, everything in an explanatory position. That's precisely the point I was trying to get to.

I just happen to consider the explanation that a rock sitting on top of a mountain having "potential energy" to be relatively content free.

There's always a tension in physics (or has been for a couple of centuries or so) between force-based explanation and energy-based explanation.The force-based explanation (gravity) of why the rock might move downhill makes vastly more sense to me than the notion that it has "potential energy". However, the force-based explanation is not always clearly the right one either.

Also, I wasn't referring to "the idea of energy stored by being in motion". This is precisely the hangup that trips up so many. An object doesn't have energy because it is moving. And it doesn't move because it has energy. The motion and the energy are the same thing, just two different ways of talking about the same thing. The distinction matters because the way we've developed the semantics of "motion" and "energy" in physics means that, for example, "motion" is not something that is transferred between objects, but "energy" is.

A static point mass in a gravitational field is already at its lowest energy state (a literal ground state if you will). It can only really do one thing, which is to stay. The logarithm of the number of states then is zero. So in some sense it cannot encode information at all. In fact I think more generally speaking, things that are at a global minimum of energy level cannot really be used to encode information (unless you have a mechanism to add entropy w/o increasing energy), because they have one state, and the log of the number of states then gives you zero bits. Probably another way to look at the idea that gravitational potential path-independence means memorylessness means devoid of bits of information.

The rock is continuously applying pressure to the mountain. That's why we have round planets and not huge random looking rocks. On an atomic level, the atoms themselves are full of action, though that will take a really long time to see the consequences of that.

ps: I subscribe to the heat death theory.

That rock is moving though, at c through time.

I love it. Was susskind inspired by this at all with his complexity=action (duality) [1] hypothesis?

Theres a bunch of lectures of him on YouTube going off about how complexity increases asymptotically greater than entropy in a black hole, but I need to refresh myself on the lecture. Disclosure: I'm an idiot, and may be spewing nonsense

[1] https://en.m.wikipedia.org/wiki/CA-duality

You forgot to mention that Prigogine's model includes a system boundary. Within the system, the 2nd law of thermodynamics no longer holds - the system does not tend towards entropy, as the system ingests energy and exports entropy.

Put in Prigogine's terms: the system is not at, and does not reach, equilibrium (the state that most other chemical science tends to assume).

I absolutely adore the simplicity behind this: Energy must balance, so it flows from high concentrations to lower concentrations. Things that help that flow are selected for.

From that springs everything we are. Utterly amazing to me that from a gradient plus some random chemicals plus time equals humans, sex, violence, loss, birth, love, games, music, and so much more.

All just to help the earth cool down a little bit faster.

Absolutely none of this follows

It doesn't help the earth cool down faster, it actually traps energy for longer in metabolic processes. But it does red shift it. The film of muck on the surface that we call life lowers the planet's albedo and the radiation that shines out of it is of a longer wavelength than if it were just reflected.

> Things that help that flow are selected for.

I don't get this part, why does this follow?

Why would life that transfers heat faster get selected for? This seems backwards to me: in reality it seems like life that is more capable or more adapted reproduces more, and that results in more heat moving around most of the time.

But progress can go backwards, if there were a nuclear war this would reduce heat transfer.

So where's the bacteria outcompeting moon dust?

Theories which make life inevitable are inherently shaky because we have 1 sample.

You can't have theories without life to conceive of them, so in fact life is inevitable under any theory.

That's just antrophic principle, no need for any selection pressure or any particular theory at all. That's why all of them are shaky.

Where are the conditions for life on the Moon? You can't have something if the conditions to form it are missing. Your question is equivalent to asking why stars don't form outside dust clouds.

There are ways for the matter on the moon to dissipate energy faster than moon dust. We could build a moon base for example. It doesn't do it.

In fact as far as we know - most of the space in the universe is doing the dissipation in a very inefficient way.

Which means the theory that it will do it simply because of the "selection pressure" is empirically wrong.

Let's say a huge asteroid sterilized Earth 100 years ago. What could the life do to outcompete that? Was it the result of this "selection pressure" that it didn't or was it simply result of starting conditions and gravity?

This theory seems to provide almost no predictive value it just takes a thing that happened once and makes a story about how it had to happen.

> Which means the theory that it will do it simply because of the "selection pressure" is empirically wrong.

Again, this is not true. We have empirical evidence that life on Earth began as soon as it could. And the universe doesn't spontaneously do things as you're wishing it to do to support your argument.

> Let's say a huge asteroid sterilized Earth 100 years ago. What could the life do to outcompete that?

That doesn't negate anything. Entropy increases over time. Given the various conditions available in the universe, its processes follow that directive relevant to their conditions.

> And the universe doesn't spontaneously do things as you're wishing it to do to support your argument.

That's the whole point. The theory reduces to "if conditions are right life will happen" which moves the whole predictive power to the "conditions are right" and leaves the theory with 0 value added.

> It's fascinating to me that the complexity of life always goes up.

This isn't true- many things evolved to be simpler over time. For example, some viruses are beleived to have evolved from parasitic bacteria, which themselves evolved from free living bacteria. Many other parasites have simplified and lost the ability to survive without a host. You also have examples like many cave and underground animals losing eye sight and pigmentation. Also consider things like marine mammals losing limbs land mammals had, and many sedentary/fixed marine invertebrates evolving from free swimming ones.

There are costs to complexity, and so organisms evolve it when needed, and lose it quickly when it isn't giving an advantage... there is not an "arrow of complexity" that only moves one direction.

A great example is tunicates. They're a subgroup of chordates, and so are closely related to us, but they've been brutally simplified over time.

> It's fascinating to me that the complexity of life always goes up.

Sounds like observer bias.

In terms of number of individuals, the vast vast majority of life on this planet is single cell prokaryotes, and always has been. And in terms of total bio-mass only plants exceed them but that's just because of how plants work (cover the surface with bio-solar-panels)

Both bacteria and archaea haven't substantially changed in 3.5-4 billion years. They swap genes as needed, and drop them when they're too costly and unneeded. And they're dominant, and everywhere

They were here since just a few hundred million years (or less) after the earth formed. And when conditions on the planet become more hostile again, in the long run it could be the case that eukaryotes are just a historical blip (and a fluke, to boot).

And if there's something we recognize as life out there beyond earth... it's likely to look like prokaryotes. The galaxy might be swimming in that kind of thing.

There is a strong philosophical/ideological bias in our culture to see the world in terms of "progress"; a teleological bias, seeing the universe as proceeding in stages towards some order. It just so happens we almost always seem to define this progress as "inevitably" leading to ... us, or "beyond" us into whatever fantasy for the future is laying dormant in the present. It feels remarkably pre-Copernican.

I don't understand what you're balking at. I didn't see anyone imply that the complexity of life going up leads to "us". The complexity of life does trend up. Nothing you mentioned refutes that.

> It's fascinating to me that the complexity of life always goes up.

A lot of lifeforms evolve to be more simple, not more complex -- I think what you have is sort of a distribution of complexity, and as life continues to evolve, the upper bound keeps getting pushed up as some organisms push the boundary of complexity, but I don't think it's at all true that in general life involves to be more complex.

Single-celled organisms are almost infinitely more complex than, say a self-replicating RNA molecule. That again is vastly more complex than a protein or an amino acid. Similarly, a human is nearly infinitely more complex than a single-celled organism.

Evolution causes organisms to fill an ecological niche. Simple niches for simple organisms will always exist, and simple life will always exist, even as the upper bounds of organic complexity trend unerringly upward.

Life tends toward complexity, but that doesn't obviate the need for simple organisms.

Arguably, viruses exist by shedding as much complexity as possible. Trim their genome to the absolute minimum which can still propagate.

Which has some analogy to computer viruses (specially in simulated environments where they are generated through optimization algorithms, rather than being engineered by an human software developer)

As others have noted, it is more about the maximum complexity increasing than mean or median. Simple structures keep existing as long as they have their niche, and a human's niche is not (yet) that of viruses.

This also reminds of Gall's law that complex systems evolve from simpler ones.

You can also see it in neural nets, where larger ones have a higher spatiotemporal resolution and can do more complex things.

More model capacity allows to model the environment and self more accurately which allows to outperform other structures in negentropy consumption often at the cost of the other structures (zero sum).

This exerts selection pressure toward increasing complexity.

That also largely explains group and country disparities.

I am not sure that non-evolving things really fit into the same pattern. A burning fire does not necessarily displace inert matter, nor did it arise from competition.

Physics and chemistry are more fractal-like possibly the result of enumeration of all computational structures (see Tegmark's mathematical universe hypothesis or Wolfram's ideas on the computational universe). Not fractal-like in terms of self-similarity (although there is some at different scales), but fractal-like in terms of chaotic complexity like a pseudorandom number generator but with more rule-like structures in between. Wolfram also classified such computational patterns.

> It's fascinating to me that the complexity of life always goes up. Outside extinction events, complex life generally seems to become more favourable over time. It's interesting that (to my knowledge) we don't see an ecosystem lose complexity in its entirety unless it's dying.

I think that's a biased take. Complex life may be better at exploiting a more table environment, but too much disruption can kill it. "Less complex" life seems able to adapt more quickly to more extreme changes (e.g. the much greater diversity of bacterial metabolism). Extinction events are inevitable, and environmental disruption will inevitably become more and more challenging until everything dies (though it may take a billion years), and during that time I think the trend will be for complexity to decrease.

So ultimately, I think you're overgeneralizing one phase.

Nit-pick:

> It's fascinating to me that the complexity of life always goes up

Depending (heavily) on how we define complexity, this is not always true. If we define complexity as the number of genes an organism has (a big if there), then we see that evolutionary pressure will often get rid of genes to improve fitness. This is somewhat common in bacteria and other 'small' organisms that are in 'stable' environments, but can happen even in 'higher' lifeforms (Sorry, I can't seem to remember the paper on this, but I vaguely recall it had something to do with jellyfish. Again, sorry!)

Stephen Gould wrote a whole book disputing this idea that the complexity of life increases: "Full House: The Spread of Excellence from Plato to Darwin." The basic argument is that almost all life on Earth is still prokaryotic...the rest of us are just a rounding error. He wrote several books about how evolution was not directional, notably "Wonderful Life" and "Time's Arrow". I'm not completely convinced by any of these, but worth reading.

Effectively, we've been out-competed in all the low complexity niche; life adds complexity to take advantage of novel niche where there is less competition.

Another cool perspective is that simple organisms evolved to coordinate with each other to build complex organisms that could protect the simple organisms in hostile environments they might not / would take longer to explore. Think about all the gut bacteria that survives in humanity during reproduction and viruses and bacteria that invade and hitch rides. You can view humans as the life form or you can view the bacteria within us as the life form and humans are the organic machine they’ve constructed and control (eg look at how the gut/brain connection can effect your mood and decision making without you even being conscious to it)

I think that is a far more fun way of looking at it!

But the bacteria aren't the whole story - we also have our own cells, all doing their thing and all participating (even if bacteria in us are -also- participating). We're just groups of trillions of cells all working together to keep themselves alive and reproducing.

And then we go work together with other blobs of trillions of cells, just to further that goal: survival of the cells.

These groups of cells that started working together many, many billions of generations ago, are now looking at space exploration, colonising other planets, and wondering if there are other big groups of cells on other planets.

There's no way they'd have gotten there if they'd kept living alone as single-celled organisms.

That's fun to think about.

So each of us is basically an AGI for the tiny cells

The maximum complexity increases, but the average complexity? Bacteria outnumber us.

It's more that it diffuses evenly rather than having a specific direction.

My first reaction was: wat? Isn't that only from the perspective of a relatively complex organism? Life constantly explores in all the directions it can, so it's no wonder that one frontier of that exploration is towards increasing complexity. And there are natural limits to decreasing complexity. (Though those limits are beyond what we would call "life". You don't need to be capable of reproduction if you can borrow a host's capability. We're all just host mechanisms for the parasitic reproduction of Pollan's corn, Adams's digital watches, and bad analogies.)

Maybe that's what the abstract referred to as "the Theory of the Adjacent Possible"? I've only read the abstract.

But your argument of ecosystem complexity is totally valid. Though I guess if an ecosystem decreases in complexity, then it has to end up in a different type of simplicity than it was the last time it was there, because otherwise you already know that it evolves out of that spot (assuming some amount of determinism).

Temporarily, though, this can and does happen. Invasive species often obliterate a lot of complexity, presumably until either their weaknesses are discovered through the very changing conditions that allowed the natives to flourish in the first place, or until they evolve complexity of their own.

There's another way to derive increasing complexity from a small number of laws, though. There are multiple resources and multiple ways to access them. Optimizing for any one of those results in overspecializing and becoming less fit for accessing most of the others. There's no one best answer that works for everything. You always have a delicate balance between overgeneralizing and overspecializing, and the area between those provides a lot of different ecological niches, and even more if you look at the battle stretched out over time. (The configurations are unstable; you could have a thousand species optimized for particular resources that get clobbered by a generalist that poisons the specialists, then the energy required by the poisoners makes them lose out to generalist nonpoisoners, which enables specialization again, not to mention evolved immunity... the wheel goes round and round, picking up crud as it rolls.)

I would say we have a complex organism bias though, really the most successful life is simple, more than 90% of earth's biomass is plants, ants, fungi, bacteria (obviously some of those are more complex than others, but none of them are posting on HN quite).

Sounds like the complexity of life follows a power law distribution, where most of it is simple to moderately complex, but a few species are orders of magnitude more complex than the vast majority. Eg, the vast majority of complexity among living organisms derives from just a few species.

> It's fascinating to me that the complexity of life always goes up.

I feel this is only the case because the ecosystem keeps receiving useful/low-entropy energy inputs from the Sun.

As entropy goes up in the universe complexity first increases and then decreases. And life is probably a consequence of this.

Sean Carroll explains it quite well in his book The Big Picture and also in this video series from minute physics

https://m.youtube.com/playlist?list=PLoaVOjvkzQtyZF-2VpJrxPz...

I think you're describing the maximum complexity of life over time, which is an interesting thing to think about: the life forms that stand out among the rest for "how far" they evolve.

In terms of other measures (total biomass, long-term survival, short-term adaptability), the life forms that stand out, historically, are very different. Ants, roaches, sharks, bacteria.

I think it was a Greg Bear novel, but a line from it struck me as insightful... paraphrased badly, "even evolution is evolving".

I think the trend towards complexity is more just due to more complex things being built out of less complex ones - complexity creates/supports greater complexity, so it's a natural progression.

For higher level animals complexity may also be more inherently favorable since it supports a more customized environmental "fit", and helps in the predator-prey arms race.

Yeah this is it. It's very unlikely to see something which cannot be decomposed into similar parts come into existence. Something highly complex and irreducible.

But simple things are likely to come into existence. So given that we see complicated things, we should assume that they are reducible, and that they came from simpler things. This creates the appearance of a "trend" as you say. But it's really that the complicated things couldn't exist before and now they can.

Another effect is that it's possible to be more fit (in the Darwinian sense) when you are more complicated. The fittest system with complexity n is <= the fitness of a system with complexity >n. The rate at which things are destroyed is inversely proportional to their fitness (definitionally). So more complicated things can be better at staying around.

> complex life generally seems to become more favourable over time.

Talk more about this, as I'm not sure how you are arriving at this conclusion... it feels a bit like when people talk about evolution being in some way directed as opposed to just being.

Evolution is "directed" towards the exploitation of free energy, inevitably producing increasingly complex niche methods of obtaining and dissipating energy.

I've long believed that as the overall entropy of the universe increases, life forms evolve greater information processing capabilities to adapt and thrive in increasingly disordered environments.

https://en.wikipedia.org/wiki/Anthropic_principle

In Count to the Eschaton the "grand project" is "the sophistication of all matter" and it's been going on since the beginning.

> The Count to the Eschaton Sequence is a six-novel series written by John C. Wright.

There are some excellent if controversial theoretical explanations for this in Assembly Theory

Hey this dude comes to mind. Anyone remember him? Whatever came of his theories?

I found them to be implausible due to the implications they’d have on the Drake equation

https://www.quantamagazine.org/a-new-thermodynamics-theory-o...

https://xkcd.com/384/

Two reliable effects predict runaway complexity for any initially simple life form in a non-trivial environment.

1) BOOT STRAPPING COMPLEXITY: Non-trivial static environment: Something simple is rarely the global efficiency optimum in a non-trivial environment. There is nothing trivial about chemistry and the myriad of terrains created by physics in the non-living world. So simple living things, in competition, quickly get more complex.

2) ACCELERATING COMPLEXITY: Dynamic environment: In a competitive ecosystem of continually diversifying life forms, the ecosystem gets more complex, so competing in the ecosystem both enables and requires more complexity.

The exponential increase in complexity produces qualitatively new modes of complexity leveraging beyond initial resources: such as specialization, food chains, parasitical strategies, mutual or cyclical symbioses, discarded products that become new resources, colonization of new environments and energy sources, flexible behaviors based on conditions, greater utilization of existing environments and resources, cooperation within multi-cell colonies, specialization and reproductive coordination within cell colonies (creatures), communication and coordination between similar and different life forms, tool use, tool creation, environment shaping, anticipation and planning, curiosity driven learning, aggregation and recombination of knowledge, resource trading systems, systems to promote positive sum interactions, and suppress negative sum interactions, engineering, invention, science, automation, etc.

TLDR: Non-trivial environments provide initial opportunities for complexity to improve efficiency. Complexity feedback in ecosystems exponentially accelerates further complexity. Exponential growth of life's complexity on Earth shows no signs of relenting.

Qualitatively new forms of complexity keep appearing. Conscious intelligence, culture, technology and automation are more continuations than breaks from this trend.

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