5 ms·

context: https://en.wikipedia.org/wiki/What_Is_Life%3F https://en.wikipedia.org/wiki/What_Is_Life%3F more: "A New Physics Theory of Life" https://www.quantam

by pella 9y ago

context: https://en.wikipedia.org/wiki/What_Is_Life%3F https://en.wikipedia.org/wiki/What_Is_Life%3F more: "A New Physics Theory of Life" https://www.quantamagazine.org/a-new-thermodynamics-theory-of-the-origin-of-life-20140122 https://www.quantamagazine.org/a-new-thermodynamics-theory-o... HN: https://news.ycombinator.com/item?id=13103215 https://news.ycombinator.com/item?id=13103215 "An MIT physicist has proposed the provocative idea that life exists because the law of increasing entropy drives matter to acquire lifelike physical properties." "Life does not violate the second law of thermodynamics, but until recently, physicists were unable to use thermodynamics to explain why it should arise in the first place. In Schrödinger’s day, they could solve the equations of thermodynamics only for closed systems in equilibrium. In the 1960s, the Belgian physicist Ilya Prigogine made progress on predicting the behavior of open systems weakly driven by external energy sources (for which he won the 1977 Nobel Prize in chemistry). But the behavior of systems that are far from equilibrium, which are connected to the outside environment and strongly driven by external sources of energy, could not be predicted." or: http://nautil.us/issue/34/adaptation/how-do-you-say-life-in-physics http://nautil.us/issue/34/adaptation/how-do-you-say-life-in-...

westoncb 9y ago
After reading the Nautilus article, my understanding of England's 'dissipation-driven adaptation' is: a physical account of why life-like structures would likely occur (and persist) even at levels far more basic than what we would call organisms. The basic structure (of his system) follows that of natural selection and evolution in that there is an element of randomness constructing forms, and something environmental which determines fitness of competing forms—but it differs in what constitutes fitness. In England's theory, we should expect irreversible, dissipative systems to persist simply because of their irreversibility; if they could be reversed, they would return to an indistinguishable part of the background from which they emerged. If his theory is true, there is a natural 'inclination' at a more basic material level for life-like structures to emerge, so the probability of life evolving 'randomly' is more likely than we had reason to believe before. Furthermore, it gives us more general criteria for attempting to manually 'evolve' life-like systems, since we mimic life a more basic level than genetics (aiming to produce things with high likelihood of being irreversible). (I'd appreciate any correction on parts I may have gotten wrong!)
- danielvf 9y ago
  I've not studied this, but doesn't that theory seems to conflate "likely to persist" with "likely to emerge"? For example, the US prison population tends to be far more violent than you would expect - in my state's prisons more than one out of four prisoners are there for either homicide or rape. This is because the longer sentences for those crimes. Because of their "persistence", there are sixty times more people in prison for thirty year crimes than for six month crimes, compared to the relative conviction rate for those crimes. However(!), this persistence tells us nothing about the base occurance rate. There aren't sixty times more murders and rapes than six month sentence crimes. So it also seems that the persistence of life does not affect the probability of life's arising in the first place. Or am I missing something?
  - westoncb 9y ago
    I think it follows the same basic pattern as biological evolution: there is a semi-random process that introduces new forms, but when you see a preponderance of some particular form (or attribute) it's simply due to the fact it wasn't eliminated like competing forms/attributes were. I think what's missing from my description though was an account of how the dissipative efficacy of the non-reversible formations compounds in time. I re-checked the article and it is IMO vague on the subject aside from saying that that does in fact happen. In any case here's a relevant quote by Jeremy England given in the article: While any given change in shape for the system is mostly random, the most durable and irreversible of these shifts in configuration occur when the system happens to be momentarily better at absorbing and dissipating work. With the passage of time, the “memory” of these less erasable changes accumulates preferentially, and the system increasingly adopts shapes that resemble those in its history where dissipation occurred. Looking backward at the likely history of a product of this non-equilibrium process, the structure will appear to us like it has self-organized into a state that is “well adapted” to the environmental conditions. This is the phenomenon of dissipative adaptation.
    - danielvf 9y ago
      Doesn't that just say roughly that "a new form that is more likely to persist in a given environment came from a previous form that was more likely to persist in that given environment"? That almost boils down the same thing as before. The persistence of life still seems entirely orthogonal to the odds of a self replicating life arising in the first place, right?
george_ciobanu 9y ago
I flirted with this idea for a long time after hearing it and wanted to like it but in hindsight it's pretty easy to prove it wrong. Yes entropy creates pressure on life and has a hand in pretty much everything, but Earth has an abundance of free (Gibbs) energy that insulates it and creates a new kind of environment and conditions. It's like saying that hunger drives social complexity. It's part of it but it doesn't drive it. Yes you could apply Newtonian physics to everyday social encounters and structures but they're way too broad and generic to derive meaning conclusions at the interpersonal level.
starchild3001 9y ago
I've long thought "life is inevitable". Why? In a universe where every possibility plays out, some outcomes are bound to lead to life. [Diverse] Chaos => universal turing machines occurring somewhere + random codes being executed + sufficient computation => life. I'd love to see these notions made rigorous. Somehow they appear obvious to me. Order (i.e. life) is necessary to reach the ultimate unordered state (i.e. a cosmic soup of energy)? Now that's a pretty non-trivial statement. Video by the author: https://www.youtube.com/watch?v=e91D5UAz-f4 https://www.youtube.com/watch?v=e91D5UAz-f4
- jamesrcole 9y ago
  > In a universe where every possibility plays out I think that's an assumption.
- root_axis 9y ago
  > In a universe where every possibility plays out Why would we assume this is the case? Certainly an infinite number of possibilities have already been ruled out, like the possibility that the entire universe would be totally devoid of all matter.
- xelxebar 9y ago
  This is a beautiful, romantic view, though I don't see how it can me made all that physically rigorous interpretation. Here are some thoughts on the philosophy of what you say. > Life is inevitable On one level, this is a tautology: the physics of the universe are such that life has formed therefore life occurs with 100% frequency in all known universes. On a different level, it's not too hard to build "physics" that are too trivial to even encode Peano Arithmetic much less "life" as we would identify it. Thus life isn't obviously inevitable in all physical models of the universe, so we can take the emergence of life as an "experimental constraint". On a personal level, I too feel the importance of life. However, I don't think any of that special feeling is compromised by taking life to not be somehow "universally fundamental" in some way. > Life is a fractal The mathematician in me kind of flinches at this a bit. :p Fractals are super cool though! But, heck, the eastern coast of Cambodia exhibits fractal-like qualities too. As do coupled-pendulum setups and the x86 execution pipeline. This line of thinking feels to me like putting The Mysterious into some spiritually special place in our thinking. For myself, when I think something is "obviously true" I usually find that I just don't know enough to appreciate the intricacy of what's really going on. Dunning-Kruger and all that. Anyway, just some 2 cents.

by pella 9y ago

westoncb 9y ago

After reading the Nautilus article, my understanding of England's 'dissipation-driven adaptation' is: a physical account of why life-like structures would likely occur (and persist) even at levels far more basic than what we would call organisms. The basic structure (of his system) follows that of natural selection and evolution in that there is an element of randomness constructing forms, and something environmental which determines fitness of competing forms—but it differs in what constitutes fitness. In England's theory, we should expect irreversible, dissipative systems to persist simply because of their irreversibility; if they could be reversed, they would return to an indistinguishable part of the background from which they emerged. If his theory is true, there is a natural 'inclination' at a more basic material level for life-like structures to emerge, so the probability of life evolving 'randomly' is more likely than we had reason to believe before. Furthermore, it gives us more general criteria for attempting to manually 'evolve' life-like systems, since we mimic life a more basic level than genetics (aiming to produce things with high likelihood of being irreversible). (I'd appreciate any correction on parts I may have gotten wrong!)

danielvf 9y ago
I've not studied this, but doesn't that theory seems to conflate "likely to persist" with "likely to emerge"? For example, the US prison population tends to be far more violent than you would expect - in my state's prisons more than one out of four prisoners are there for either homicide or rape. This is because the longer sentences for those crimes. Because of their "persistence", there are sixty times more people in prison for thirty year crimes than for six month crimes, compared to the relative conviction rate for those crimes. However(!), this persistence tells us nothing about the base occurance rate. There aren't sixty times more murders and rapes than six month sentence crimes. So it also seems that the persistence of life does not affect the probability of life's arising in the first place. Or am I missing something?
- westoncb 9y ago
  I think it follows the same basic pattern as biological evolution: there is a semi-random process that introduces new forms, but when you see a preponderance of some particular form (or attribute) it's simply due to the fact it wasn't eliminated like competing forms/attributes were. I think what's missing from my description though was an account of how the dissipative efficacy of the non-reversible formations compounds in time. I re-checked the article and it is IMO vague on the subject aside from saying that that does in fact happen. In any case here's a relevant quote by Jeremy England given in the article: While any given change in shape for the system is mostly random, the most durable and irreversible of these shifts in configuration occur when the system happens to be momentarily better at absorbing and dissipating work. With the passage of time, the “memory” of these less erasable changes accumulates preferentially, and the system increasingly adopts shapes that resemble those in its history where dissipation occurred. Looking backward at the likely history of a product of this non-equilibrium process, the structure will appear to us like it has self-organized into a state that is “well adapted” to the environmental conditions. This is the phenomenon of dissipative adaptation.
  - danielvf 9y ago
    Doesn't that just say roughly that "a new form that is more likely to persist in a given environment came from a previous form that was more likely to persist in that given environment"? That almost boils down the same thing as before. The persistence of life still seems entirely orthogonal to the odds of a self replicating life arising in the first place, right?

george_ciobanu 9y ago

I flirted with this idea for a long time after hearing it and wanted to like it but in hindsight it's pretty easy to prove it wrong. Yes entropy creates pressure on life and has a hand in pretty much everything, but Earth has an abundance of free (Gibbs) energy that insulates it and creates a new kind of environment and conditions. It's like saying that hunger drives social complexity. It's part of it but it doesn't drive it. Yes you could apply Newtonian physics to everyday social encounters and structures but they're way too broad and generic to derive meaning conclusions at the interpersonal level.

starchild3001 9y ago

I've long thought "life is inevitable". Why? In a universe where every possibility plays out, some outcomes are bound to lead to life. [Diverse] Chaos => universal turing machines occurring somewhere + random codes being executed + sufficient computation => life. I'd love to see these notions made rigorous. Somehow they appear obvious to me. Order (i.e. life) is necessary to reach the ultimate unordered state (i.e. a cosmic soup of energy)? Now that's a pretty non-trivial statement. Video by the author: https://www.youtube.com/watch?v=e91D5UAz-f4 https://www.youtube.com/watch?v=e91D5UAz-f4

jamesrcole 9y ago
> In a universe where every possibility plays out I think that's an assumption.
root_axis 9y ago
> In a universe where every possibility plays out Why would we assume this is the case? Certainly an infinite number of possibilities have already been ruled out, like the possibility that the entire universe would be totally devoid of all matter.
xelxebar 9y ago
This is a beautiful, romantic view, though I don't see how it can me made all that physically rigorous interpretation. Here are some thoughts on the philosophy of what you say. > Life is inevitable On one level, this is a tautology: the physics of the universe are such that life has formed therefore life occurs with 100% frequency in all known universes. On a different level, it's not too hard to build "physics" that are too trivial to even encode Peano Arithmetic much less "life" as we would identify it. Thus life isn't obviously inevitable in all physical models of the universe, so we can take the emergence of life as an "experimental constraint". On a personal level, I too feel the importance of life. However, I don't think any of that special feeling is compromised by taking life to not be somehow "universally fundamental" in some way. > Life is a fractal The mathematician in me kind of flinches at this a bit. :p Fractals are super cool though! But, heck, the eastern coast of Cambodia exhibits fractal-like qualities too. As do coupled-pendulum setups and the x86 execution pipeline. This line of thinking feels to me like putting The Mysterious into some spiritually special place in our thinking. For myself, when I think something is "obviously true" I usually find that I just don't know enough to appreciate the intricacy of what's really going on. Dunning-Kruger and all that. Anyway, just some 2 cents.