Thank you for your comment! And yes, that is a correct summary of Assembly Theory's definition of life. What's interesting is that the number 15 is an empirical threshold derived from experimental data and from theoretical modeling using Earth life. AT doesn't say it will always be 15, maybe there's another lineage of Life where the threshold is higher or slightly lower. Depending on the background abiotic noise, there is always some number where the universe shifts from randomness to selection. If we were to find an alien system where the abiotic noise is higher, maybe the threshold is 18 instead of 15. But the underlying logic is the same. This makes AT truly agnostic for finding life elsewhere.
Every once in a while, I happen across a piece of writing that changes the paradigm. It's why I am here on Substack to begin with. This is one of those pieces, and thank you to Venkatesh Ranjan for writing it!
You illustrate an age-old conundrum that we face when trying to differentiate matter from life: it escapes all attempts to define it via a characteristics approach. I noted this in an easier essay as well, where I wrote:
"A mule, for example, cannot reproduce, yet nobody would doubt that it’s alive. A virus, on the other hand, can reproduce, but most biologists consider it to be non-living because it depends on other species to do so. We wouldn’t argue that a crystal is alive, yet it grows. On the other hand, some bacteria go through dormant periods where they do not grow or metabolize at all, yet we still consider them alive."
The delineation here is fuzzy, so I concluded that life is merely a special type of matter better suited to dissipating energy in accordance with the second law of thermodynamics. I suggest that our brains, to make sense of the universe, had drawn an arbitrary line between what is living and non-living.
If I am understanding correctly, however, Assembly Theory claims that this line is not arbitrary at all; any objects that require more than 15 steps to produce on the Assembly Theory Index and are duplicated, necessarily require a biotic origin because they are otherwise too improbable to have a chemical origin.
This ties right into the "knowledge" aspect of human progress: That the universe is looking for ways to accelerate energy dispersion and that life contains knowledge that compresses the time required to do so. Human industrial and technological actions, which require higher levels of knowledge, are merely extensions of this same process.
The implications here, however, are interesting, for it would also hold that our creations, including things like a Mars rover, are also "life" by this same definition; an extension of living processes. Mind-blowing.
I will be editing and revising my essay on this topic soon to include a discussion of assembly theory.
Thank you for the explanation. Walker's book is on my reading list for this year. I still have ton of problems with AT. For example, we are not continuous object on molecular scale but more of a stationary pattern: we exchange water and gases with the environment continuously. The lego castle is bunch of plastic blocks with the same chemical composition if we look close enough, while a salt precipitates from the hot spring can be considered complex if we look from far enough and give it a long time. There are just too many arbitrary choices here.
In response to your larger point about Assembly Theory making arbitrary choices, I think that any new theory trying to develop a new explanatory framework will make choices that seem arbitrary in the moment, but then may go on to seem obvious in retrospect. For example, the choice to treat energy as a quantized property to explain away the ultraviolet paradox in the early days of quantum mechanics. AT is barely fifteen years old, and is still finding its ground. There are debates to be had about what all of this means if AT is 'true,' in the sense that it has explanatory power.
For stationary pattern vs object comparison, I agree that we are a flow of matter. But AT doesn't care about the individual atoms. AT is about the Construction Path required to hold that pattern together. So, for example, even if we swap every water molecule in our body, the instructions and machinery to keep those molecules in a ‘Human-shaped’ configuration remain high-assembly ( i.e., DNA, proteins, cellular structures etc). AT provides a way to measure the complexity of the template.
As for salt being precipitated, no matter how long you wait or from how far you look, a salt crystal is just a simple repetition of a 1- or 2-step unit (i.e., NaCl, say). It has a high copy number, but a very low Assembly Index. A history of selection is not needed to make a salt crystal. Basic physics/chemistry is enough.
And for the LEGO castle example, the castle itself is an “object” as per AT. You will never find two identical 1,000-piece Lego castles in the desert by accident, no matter how much time passes. The blocks are just plastic, sure, but the arrangement of those blocks into a specific castle requires a Constructor (a human or a machine).
Finally, I would love to hear your thoughts on Walker’s book when you get a chance to read it. Please do write about it!
In case of the salt crystal, I was talking about the whole formation as an object: carbonates, chlorides, etc, precipitating in order, forming a pattern in time and space. Robert Hazel claims that some modern minerals require an entire Earth geological history to appear, and then there is a question about a supernova explosion needed to create Na and Cl atoms :) I think, because I am trained as experimental chemist, sometimes I might miss the nuances, but also, the ultimate answer to the question of the origin of life is still the chemical sequence of the events reproduced in the lab.
Thank you for your comment! And yes, that is a correct summary of Assembly Theory's definition of life. What's interesting is that the number 15 is an empirical threshold derived from experimental data and from theoretical modeling using Earth life. AT doesn't say it will always be 15, maybe there's another lineage of Life where the threshold is higher or slightly lower. Depending on the background abiotic noise, there is always some number where the universe shifts from randomness to selection. If we were to find an alien system where the abiotic noise is higher, maybe the threshold is 18 instead of 15. But the underlying logic is the same. This makes AT truly agnostic for finding life elsewhere.
This seems like total sudo science. I don’t understand the premise.
Every once in a while, I happen across a piece of writing that changes the paradigm. It's why I am here on Substack to begin with. This is one of those pieces, and thank you to Venkatesh Ranjan for writing it!
You illustrate an age-old conundrum that we face when trying to differentiate matter from life: it escapes all attempts to define it via a characteristics approach. I noted this in an easier essay as well, where I wrote:
"A mule, for example, cannot reproduce, yet nobody would doubt that it’s alive. A virus, on the other hand, can reproduce, but most biologists consider it to be non-living because it depends on other species to do so. We wouldn’t argue that a crystal is alive, yet it grows. On the other hand, some bacteria go through dormant periods where they do not grow or metabolize at all, yet we still consider them alive."
https://risknprogress.substack.com/p/a-fortuitous-planet-part-2?r=8frpw
The delineation here is fuzzy, so I concluded that life is merely a special type of matter better suited to dissipating energy in accordance with the second law of thermodynamics. I suggest that our brains, to make sense of the universe, had drawn an arbitrary line between what is living and non-living.
If I am understanding correctly, however, Assembly Theory claims that this line is not arbitrary at all; any objects that require more than 15 steps to produce on the Assembly Theory Index and are duplicated, necessarily require a biotic origin because they are otherwise too improbable to have a chemical origin.
This ties right into the "knowledge" aspect of human progress: That the universe is looking for ways to accelerate energy dispersion and that life contains knowledge that compresses the time required to do so. Human industrial and technological actions, which require higher levels of knowledge, are merely extensions of this same process.
The implications here, however, are interesting, for it would also hold that our creations, including things like a Mars rover, are also "life" by this same definition; an extension of living processes. Mind-blowing.
I will be editing and revising my essay on this topic soon to include a discussion of assembly theory.
Thank you for the explanation. Walker's book is on my reading list for this year. I still have ton of problems with AT. For example, we are not continuous object on molecular scale but more of a stationary pattern: we exchange water and gases with the environment continuously. The lego castle is bunch of plastic blocks with the same chemical composition if we look close enough, while a salt precipitates from the hot spring can be considered complex if we look from far enough and give it a long time. There are just too many arbitrary choices here.
Thank you for the comment!
In response to your larger point about Assembly Theory making arbitrary choices, I think that any new theory trying to develop a new explanatory framework will make choices that seem arbitrary in the moment, but then may go on to seem obvious in retrospect. For example, the choice to treat energy as a quantized property to explain away the ultraviolet paradox in the early days of quantum mechanics. AT is barely fifteen years old, and is still finding its ground. There are debates to be had about what all of this means if AT is 'true,' in the sense that it has explanatory power.
For stationary pattern vs object comparison, I agree that we are a flow of matter. But AT doesn't care about the individual atoms. AT is about the Construction Path required to hold that pattern together. So, for example, even if we swap every water molecule in our body, the instructions and machinery to keep those molecules in a ‘Human-shaped’ configuration remain high-assembly ( i.e., DNA, proteins, cellular structures etc). AT provides a way to measure the complexity of the template.
As for salt being precipitated, no matter how long you wait or from how far you look, a salt crystal is just a simple repetition of a 1- or 2-step unit (i.e., NaCl, say). It has a high copy number, but a very low Assembly Index. A history of selection is not needed to make a salt crystal. Basic physics/chemistry is enough.
And for the LEGO castle example, the castle itself is an “object” as per AT. You will never find two identical 1,000-piece Lego castles in the desert by accident, no matter how much time passes. The blocks are just plastic, sure, but the arrangement of those blocks into a specific castle requires a Constructor (a human or a machine).
Finally, I would love to hear your thoughts on Walker’s book when you get a chance to read it. Please do write about it!
In case of the salt crystal, I was talking about the whole formation as an object: carbonates, chlorides, etc, precipitating in order, forming a pattern in time and space. Robert Hazel claims that some modern minerals require an entire Earth geological history to appear, and then there is a question about a supernova explosion needed to create Na and Cl atoms :) I think, because I am trained as experimental chemist, sometimes I might miss the nuances, but also, the ultimate answer to the question of the origin of life is still the chemical sequence of the events reproduced in the lab.