brainstorm said:
Life is a really interesting notion considering how many organisms and organism states/functions get recognized as life. Why are non-living thinks categorized as such? Does it have to do with something about the processes, ingredients, or resemblance to other things classified as living? "Organic" material seems to refer to both living and non-living materials produced by life processes, but can artificially created tissues, fertilizers, etc. be consider artificial organics?
You are again already looking for the explanation in terms of substance. What is it about a molecule that makes it living or non-living, organic or inorganic?
A systems approach sees reality as the interaction of local substance and global form. So the stress is on process (the interaction). And thermodynamics probably gives us our best "physical foundation" for framing these kinds of questions. You have entropy/information as our generalised (and dichotomous!) notion of substance. Then you have the second law of thermodynamics and its subsidiary laws (such as maximum entropy production principle or MEPP) that are our generalised notion of form.
So this then allows you to talk in general terms about dissipative structures and self-organised criticality and other scientific models of developmental process.
All structured activity in the natural world is bound by the second law. Whether we are talking living or non-living, if it is a system, it is a dissipative structure. A tornado or dust-devil are non-living examples of things that are born, develop and die as they dissipate entropy gradients.
Life clearly adds something to what is going on. The best way to describe it (following Howard Pattee) is that life involves the rate independent control over rate dependent processes. A tornado or other un-controlled developmental process just burns itself out at whatever rate is natural given the context - the slope of the entropy gradient it happens to find itself upon.
But life has memory mechanisms like DNA which can encode information (negentropy) in a rate independent fashion. A tornado encodes information only in its moment-to-moment structure (the order that is vortical motion). But life is about finding a place to put structural information to one side of a developmental process and so opening up the new possibility of controlling it, harnessing the action.
DNA does this rather directly by tossing in enzymes. Metabolic pathways are self-organising dissipative structures which simply express a natural rate. But enzymes can change the rate at which a process goes to equilibrium - burns itself out.
I'm sure you actually know all the basic biology. But the point is that we cannot see anything to distinguish the organic from the inorganic if we are just focused on the notion of material substance.
We have to take a systems view that deals in both substance and form. The most basic or physical version of systems thinking these days is thermodynamics. It has invented a notion of substance which is itself dichotomistic - signal~noise, or information~entropy. And it has framed some absolute laws, although this is still a work in progress as debate about the status of MEPP and dissipative structure theory shows.
Note how the laws of thermodynamics - the general model of form - are also dichotomous. We have the laws for closed systems (or isolated ones if we are being strict) and laws for open ones. This distinction does not actually work that well and is likely to be replaced eventually by a more basic division between equilbrium structures (or processes) that are changing/expanding and ones that are static/unchanging.
There is a curious thing going on. People are naturally obsessed by what is fundamental. And they take that to mean "the very small", "the irreducible substances of existence". So they are looking for ultimate answers in terms of particles. Yet as soon as you talk about atoms, you need their antithesis too - the void. So we end up with dichotomous substance (the vacuum as a condensate of virtual particles). And a striving for a final ToE, a quantum field theory that includes even an atomised gravity (the shape of spacetime).
Yet thermodynamics is creeping around behind all this search for the ultimate eternal stuff. It has reframed substance as information~entropy. It is working towards broad laws of form. It has already become the heart of cosmology (event horizons, black holes, inflationary phase transitions). And cosmology is of course the systems-scale view of what is fundamental.
So the answer to the OP is that again, focusing on substance as the answer to all questions is not even "physics" anymore.
But perhaps the situation is not so surprising when you consider that thermodynamics in its modern sense is still so new and unfamiliar. QM and relativity have been around nearly a century. Yet people still seem to find them disturbing and seek refuge in the comfort of 300 year old mechanics, atomism and determinism of classical physics.
Thermodynamics - of the paradigm shifting kind I'm talking about - is a revolution perhaps barely 30 years old. I am thinking of the advances of condensed matter physics, chaos theory, complexity theory, infodynamics, dissipative structure theory, event horizon cosmology, non-extensive entropy - a whole bunch of inter-related stuff that is still really clicking into place as a new broad view of reality.
Once more, why aren't people more aware of what is happening right now? I guess relativity and QM were obviously revolutions as they directly predicted new observations about the very small and very large. They quickly showed we could not extrapolate from the world we thought we knew to the extremes of scale.
Thermodynamics does not offer that same level of immediate shock to our preconceptions. We already knew the world was more complex, more of a developmental process, and thermodynamics has quietly been confirming that.
I would say we way over-reacted to the surprises of QM and are way under-reacting to deeper truths of thermodynamics. Interesting times.