Self-organisation (is a candle flame a living being...? :-)

Is a candle flame a living being when the 6 criteria of life are compared to it…?

  • Yes
  • No
0 voters

One of the most remarkable features of Nature is (at least in my opinion) that spontanous “order” can arise when a system is subjected to an external force. Obviously, this is not a violation of the Second Law, as the decrease in the entropy of the system is more than compensated by the corresponding increase in the surroundings.

A simple and well-known example are Bernoulli cells:

You’re looking at a thin layer of fluid which is heated uniformly from below. The applied external force, in this case, is the temperature difference between the bottom of the fluid layer and its surface. At low values, heat is being transported by means of radiation and thermal motion. After a certain treshold has been reached, the system swiftly and spontaneously undergoes a transition to a more efficient form of heat transport: hexagonal convection cells. The hot fluid flows upwards in the middle of the cells, cools off and then flows down again at the border. The entropy of the system has decreased (bringing order), but that of the universe has increased. As long as the temperature difference is maintained, the system will stay in this ordered state (assuming the fluid doesn’t evaporate).

Another example, though less obvious, is a candle flame.

That flame can be regarded as a system. The applied external force is the difference in chemical energy between the candle wax and the various combustion products. The flame is highly structured, with several distict areas differing in temperature and chemical composition (the image doesn’t quite tell the whole story). As long as wax and oxygen are supplied, the flame will persist (assuming it is not disturbed). As an anecdote: back in the days when I taught biology, I used to drive students nuts with this flame. I used to challenge them to present convincing biological arguments that the flame is not alive, using the established criteria for life (i.e. respiration, movement, sensory input, feeding, reproduction and growth). None passed the challenge.

An animal is obviously much more complex than a candle flame, but is comparable to it at a fundamental level - at least in my opinion. It can exist thanks to the same external force, the chemical energy of food replacing the wax. The problem with the analogy is how these ordered systems originated, because putting a match to a stack of grain does not produce a mouse, putting it to a candle will produce a flame. Once they’re there, the physical principle is the same.

There are many examples out there of even more complex physical systems that originate spontaneously, once an external force (which is always a spatial difference in energy) grows beyond a certain treshold. A tornado is large-scale example. A star such as our Sun is a fantasic manifestation as well.

I’d like to point out the unique position of plants in the above picture. Plants are not only unique in that the applied external force is the energy content of sunlight (which they convert into chemically energetic compounds), but also in that they make explicit use of the fact that Sunlight is low-entropic. Hence absorbing it and converting its energy also drastically increases the entropy of the universe, while that of the system (the plant!) decreases. This is an essential point, as photo-autotropic organisms were the first to emerge. And photosythesis not only yields food, but also materials with which an organism can reach macroscopic proportions (cellulose, starch, lignin, etc, all of which are carbohydrates).

The question is how one comes from a convection cell or a flame to, say, an animal. I happen to support the theory of evolution (which, I might add, is much broader these days than Darwin’s original work). That said, I refuse to discuss evolution on the internet. I respect the beliefs of Creationists, but such a debate is (in my opinion) pointless. As a final note, my support for the theory of evolution does not imply that I think every question has been answered. It hasn’t - and gladly so (I’d be bored to death).

Recommended reading:

Ball’s book is available as a paperback, is non-technical and will leave you scratching your head in wonder for weeks. It has the remarkable feature that a sense of wonder pervades everyone who reads it (or merely studies the many beautiful images), regardless of whether they believe in God or not. Great book! As for Penrose’s 1200 page masterpiece: I’m halfway through, it’s highly technical, the pace is very high and he makes me sweat on every page. I need to work harder on this book than any book I’ve studied before, but I’ve also learned more.

Well, those six criteria for life are obviously too simplistic if they can’t distingiush between fire and a mouse.

Your own post hold the seeds of the counter-arguement. Life, as you’ve described, increases the entropy of its surroundings to create a decrease of entropy within itself (hence the growth). For example, our bodies oxidize sugars (among other things) and use some of the energy released to synthesize proteins. Froma chemical standpoint, life is a collection of coupled reactions, an exothermic reaction paired with or “driving” one or more endothermic reactions. However, fire is only an exothermic reaction. Both life and fire create an overall increase in entropy in the system. The difference is, fire does not create any local decrease in entropy.

Perhaps. Perhaps not. They´ve been in use for a long time. And they were thought up by some very clever people. I agree with you, however, when you say that they are too simplistic, but for a different reason.

I agree with your last sentence in this quote. However, the terms endothermal and exothermal merely indicate if energy is being released during a process or not. They do not include entropy effects. When entropy is included, the free energy is commonly used.

For a candle flame such as the pictured in my first post, this is untrue. That flame is very organised, various reactions only occurring in specific regions. There are very delicate concentration gradients involved as well as temperature differences. That said, the entropy decrase associated with a candle flame is less than that of, say, a mouse.

You’re right…I was refering to the free energy. Usually, with biological reactions though, a release of energy acompanies an increase in system entropy because most such reactioons release a lot of heat.

In any case, “order” is not created in a candle flame. There are many times more equivalent thermal states of a gas than a solid. It is more ordered than a homogeneous mixture of the end products, but far less ordered than the original candlestick.

You are, in any case, missing my fundamental point. To illustrate…you are saying that there are many reactions which occur in series in specific regions of the flame, like so:

OH-(CH3)_X + O2–> State A → B → C …–> H_2_0 + CO_2, in somethign of a series. there are different pathways, but each path is essentially a series of breakdowns leading to the lowest energy state. Never do you have a molecule in any step that is longer or more complex than the original molecules of wax.

A mouse, on the other hand, will have a reaction setup mroe like this:

Glucose + oxygen + ADP -(breakdown cycles) + amino acids → CO2 + H2O + ATP. Then, you get ATP + amino acids + mRNA + tRNA’s → Proteins + ADP + RNA bits.

In other words, to satisfy the “growth” requirement, there must be catabolic processes. Fire, if it was a biological process, would be purely anabolic. Thus, even though fire can increase in size, it can never “grow” in the biological senses, and is therefore not alive.

And please don’t pick apart the balancing on my chemical equations. I never intended them as anything other than example of the larger point.

The problem as tmminionman2 pointed out lies in the definition of life. The more you try to get at it, the harder it becomes. I would guess that most people would choose a biochemical/genetic definition from those listed below, but they each have their problems.

The following definitions of life have been taken from a 1973 edition of the Encyclopedia Britannica:
with the exception of the prion* example which I inserted.

[i]Physiological: eating, metabolizing, breathing, moving, growing, reproducing, and responsive to external stimuli. A problem is that some machines can be thought of as examples.

Metabolic: boundary, continually exchanging its materials with its surroundings without altering its general properties over some period of time. Exceptions are seeds and spores that can be dormant over 100’s or even 1000’s of years. A flame in a closed room can also be thought of as a life form.

Biochemical: contain reproductive hereditary information within nucleic molecules. Exceptions include prions* & implies that theatrical organisms on different models could not be defined as living.

Genetic: Large molecules carry multiple genes sufficient to reproduce succeeding generations. These genes are responsible for various traits and can change over time. This emphasizes replication but there are many examples of living organisms such as hybrids that do no replicate.

Thermodynamic: Living systems can be defined as localized regions where there is a continuous increase in order. Counter examples have not been provided.[/i]

Personally I think that even these definitions are too limited. As an example consider a business entity as a living organism.

Could you explain sensory input. I can grasp the others (even reproduction of a sort) but unless I am mistaken, a candle flame lacks any kind of receptors from which input might be taken.

Determining whether a flame is or is not a “true” living organism isn’t my main goal. The discussion about it, however, is. It shows that the dictums laid out by scientists that have been generally accepted (i.e. the 6 criteria for life) provide merely a definition, a way of ordering things. Nature just isn’t that black or white. Anyway, here goes.

Just like organisms, the flame consumes oxygen and “food” and releases both carbon dioxide and water: respiration and feeding.

A plant senses where the light is (by means of a very simple photo-chemical reaction, by the way) and grows (i.e. moves) towards it. A flame senses where “its food” is and moves towards that (as in a fuse or a rapid fire): movement. A flame also adapts to circumstances: not enough oxygen causes it to get smaller and more yellow, yielding smoke: sensory input. It does not just “die” when the oxygen levels get less than ideal; it adapts in order to survice for as long as possible. As do human muscle cells which, under those circumstances, switch to another metabolic mode which yields less energy and lactate (an acidic substance that crystallizes inside the tissue and cause muscle aches), but they do keep going. Very similar in principle, though not in complexity.

Many organisms reproduce simply by division and each part then grows into a separate, new organism. One bacterium can cause a person to get seriously ill in this way, but it will only reproduce effectively when there’s ample food. One tiny spark can cause a dry forest to burn down; fires can grow, spread and separate. Growth and reproduction. A fire behaves like a colony of bacteria in that respect: give 'em food and oxygen, and they are unstoppable.

A virus, by the way, exhibits just one of the 6 criteria for life (reproduction), and even for that it depends 100% on the presence of a suitable host. It’s just a bundle of DNA (or, in some cases, RNA) encapsulated in protein (or, in some cases, not even that). It doesn’t qualify as a living organism itself, but uses other living organisms for reproduction. This is an interesting notion: a reproducing lifeless entity.

About the degree of order inside the flame. You shouldn’t just look at the molecular structure of the wax - structure can also be a sustained spatial distribution of matter (opposing diffusion) or energy. Plus, in the flame the reactants are brought together (i.e. the molecules are positioned in a particular way) so as to allow the process. That’s why a flame is an example of a reaction-diffusion system. The entropy of the wax is higher than that of the flame, but the combustion process raises overall entropy of the universe significantly.

The spontaneous emergence of ordered systems such as the Sun might bother Creationists because it seemingly reeks of evolution, but it doesn’t. There’s not even a hint of randomness or coincidence in the emergence of these structures, as they ALWAYS appear under the same circumstances. Evolution might (or might not) explain how one gets from a bacterium to a mouse, not how the bacterium got there in the first place.

What might bother a Creationist, however, is that a candle flame (and the Sun, and a bacterium, and possibly even you) might be merely an intermediate stage between wax and waste that happens to try and conserve itself. In other words, a self-sustaining process, here to convert food into waste. I’m not advocating this viewpoint, but it is an intriguing idea.

The notion that an applied force can lead to spontaneous complexity is, in my opinion, a very enriching one. Once you’re aware of it, you start to see forces and corresponding order everywhere.

Where the force always is a spatial difference in energy, the order is always a transport phenomenon (including the flame, although this might not be immediately obvious).

Force: difference in air pressure.
Order: tornado (serving to diminish the pressure difference).

Force: difference in temperature.
Order: hexagonal Bénard cells (serving to diminish the temperature difference). Other examples related to temperature differences are plenty: look for them :wink: !

Force: think about it!
Order: a vortex.

Force: difference in electric charge (a voltage)
Order: a flash of lightning (serving to diminish the voltage difference).

Other examples are foams, chemical systems such as the Belousov-Zhabotinskii reaction (see image below with the petri dishes). The structures are everywhere. I hope y’all will spot them while taking a hike and enjoy them as much as I do.

Again…if you were to read my explanation of growth, you would see the difference between a fire expanding, and an organism synthesizing new molecules

I’m glad you don’t teach thermodynamics. Wax at room temperature has a much lower entropy than its vapor, or any combustion product. the “order” you are describing is insignificant compared to the disorder due to the reactions occuring in the flame. At each step, the temperature increases, the molecules get smaller, and they expand to occupy more volume. This all means MORE entropy, and more disorder.

So…fire exhibits feeding/respiration, sensory input (fire exhibits a form of taxis toward fuel), and movement. The senroy input is arguable either way, but i’llc all it close enough.

Saying fire reproduces is debateable simply because there is no unit of fire we can count. you can start with one bacterium, and it divides, making 2…hence reproduction. With fire, expanding in size and reproduction are hard to distinguish. but, since fire can be divided into 2 smaller fires, we could call it reproduction.

HOWEVER…if you consult my little reaction chain, you will see that our biological definition of growth (at least the way it should be defined, as molecular catabolism) cannot be applied to fire. Everything we call “alive” performs soem kind of catabolism…fire does not, and therefore is not.

very cool posts towander, except one thing. can you please never again post any images that are bigger than the screen ? makes the thread virtually unreadable. im sure anything should fit in 640x320 or something like that.

about your question on life : the concept does not exist in any strong sense. just like the definition of a hamburger, or soup, the definition of life is something entirely arbitrary, and reflects alot more about the traditions and biases of the person/group doing the defining than of anything external to them. accourding to the 6 criteria deffinition, a candleflame is alive. but that only says something about the definition.

and i am rather persuaded that everything is just a temporary intermediary state between two extremes.

I used to. No-one ever complained :smiley: .

I agree with that. I am not comparing the entropy of the reactants and the products, but if I were then obviously the balance would be positive. You’re looking at it from a black-box perspective: add wax and oxygen, collect carbondioxide and water. Entropy and enthalpy are state functions, so what happens in the box is irrelevant for the net balance; only the difference between reactants and products counts. I agree with all that - but I’m looking inside that black box to determine how the process works. Consider, if you will, the enzymatic combustion of, say, glucose inside the body. This happens without fire and is rather slow. Enzymes provide us with a means to do so. Glucose is gripped by an enzyme, in this case hexokinase, together with a molecule of ATP. Both reactant molecules are brought into the right spatial position relative to one another and an active enzyme-substrate complex is formed. Now I’m not just looking at the outcome of the process, but rather at the METHOD used to achieve that result. And my statement is, that the absolute entropy of the enzyme-substrate complex is less than that of the glucose alone. In the same way, I’m claiming that the entropy of the flame itself (i.e. the means used to convert wax into waste), a delicate and very complex reaction-diffusion system, is less than that of the wax itself and can be regarded as an ordered system.

How about a virus…?

Sorry 'bout that. I didn’t upload the pics myself, I merely copied the URL’s suitable pics into my post.

Agreed. But the discussion doesn’t get any less interesting because of this.

This is a rather cryptic sentence. If you mean between the Big Bang and either thermal death or the Big Crunch, then I’d have to agree.

Ok, now we’re getting somewhere. In that instance, when everything is bound together, then it does seem like there is a lower entropy. However, I would be hesitant to make any such conclusions about a transition state of the reaction, beacuse entropy and free energy and other such properties are usually defined only in the “black box” sense. You look at the beggining and the end of a reaction to determine changes in those properties. looking at the transition state doesn’t tell you anything.

You can, however, make the black box smaller, and only look at individual steps in the chain of reactions. Even so, the products will all have higher entropy than the reactants. This is just saying that all of the reactions are decomposition reactions of a sort…the decrease of free energy of the products does produce a (smaller) increase of free energy somewhere else, only a dissipation of heat. a fire burning in the open is the equivalent of a 0% efficient organism, in which no useful energy is extracted from the reaction. Fire by itself drives no catabolism of any kind, so it is not alive.

Viruses aren’t alive because they can’t reproduce themselves or perform any kind of molecular synthesis. Living cells with reproduction machinery have to do the work for them.

An analogy…If a lving organism (a cell, say) is a complete computer, then a virus is just a floppy disk with instructions to make more floppy disks. Fire would be the power supply.

it’s a loose analogy, i know…computers aren’t alive…but the relationship is what’s important.

I’m not interested in the wax. Nor in the carbondioxide and water. What fascinates me, and why I started this discussion in the first place, is that far from equilibrium order can spontaneously emerge locally. In other words: I’m interested in the flame :unamused: ! The combustion of the wax is a non-equilibrium process that allows a highly complex reaction-diffusion system to emerge and sustain. It is a specific example of a general principle: apply an external force, and local order may emerge. In this case, the external force is the difference in chemical potential between the wax and the combustion products. With a tornado, it is the difference in air pressure. With Bénard cells, it is the difference in temperature. The examples are plenty.

Let’s do some numbers to illustrate the low entropy of the flame. Let’s define the entropy of the wax, which is about to be transformed into carbon dioxide and water, to be 100. Assume that the entropy of the products is 200. Regardless of HOW the wax is transformed, the net entropy increase of the universe will always be 200 - 100 = 100. I claim that the flame itself (or, in the case of enzymatic combustion, the enzyme-substrate complex) has an entropy of, say, 80. Schematically:

wax + oxygen —> FLAME (net entropy change -20)
FLAME —> carbondioxide + water (net entropy change +120)

wax + oxygen —> carbondioxide + water (net entropy change +100)

This shows the flame to be a low-entropic intermediate between wax and waste, which, upon closer examination, turns out to be a very complex reaction-diffusion system which can only “survive” for as long as the combustion of the wax continues.

In the specific case of the flame, an added “bonus” is that one might have an interesting discussion about the principles of life. As this thread has demonstrated, our current definition of what lives and what doesn’t may not be appropriate. Some may feel it is too broad, because it doesn’t rigorously exclude that flame. Others may feel that it is too narrow, because it doesn’t explicitly include viruses or, say, candle flames.

Now, you speak of the ability to reproduce or perform any kind of molecular synthesis as being an essential ingredient of life. This is an interesting point. Let’s consider a (biological) virus. There are 6 criteria of life. A virus passes only one, and even for that one it depends utterly on a suitable biological host. A virus does not eat, grow, move, sense or respirate. It is just some DNA or RNA, with or without some protein around it. Using the enzymatic machinery of the host, its DNA or RNA is being decoded and copied. In most cases a new protein encapsulation is made using the host cell’s ribosomes. Eventually, the cell dies and ruptures, so the new virus particles are released, starting the process all over in a new cell. You can isolate macroscopic quantities of the virus, dry them and put them in a flask. It will look like white powder and, provided it does not come into contact with a host, is as lifeless as salt. Reproduction? Not by itself. Molecular synthesis? Forget about it - it only consists of encoded instructions for such synthesis. Metabolism? Nope. So: is it alive? Personally, I am very much in doubt about this question. A virus has one other thing in common with truly living organisms, apart from reproduction: it mutates (which is why there is no cure for the common cold or influenza). Mutation implies adaptation to a changed surrounding and is very characteristic of life. I would say that the omission of mutation is one the biggest flaws in the 6 criteria, but that’s just my opinion.

So, tmminionman, how do you feel about viruses?

Are you just guessing that the entropy of the transition states is lower, or do you have data to back this up? because so far, you’ve decided that macroscopic order is proportional to entropy, which isn’t true. A colored gas with a rainbow pattern has more entropy than a solid with random dots of color.

Ok, we know every reaction step involves a vapor (the wax must boil off first to burn). So, these wax molecules slowly combine with oxygen in a long chain of reactions ending with CO2 and H2O. As the reactions progress, the molecules get smaller and hotter as energy is released. No reaction step creates larger molecules, or absorbs energy. Therefore, all of these steps INCREASE the entropy as the reactants make their way through the flame. In no part of the flame, no matter how long or complex the breakdown process, does entropy decrease.

See, entropy is a measure of thermodynamically equivalent states of a system. in other words, how many different initial arrangements of atoms will do the same thing? If energy is perfectly homogeneous, then there is no free energy, and nothign will happen. from an energy standpoint, ALL states are equivalent. On the other hand, if you have energy stored in a chemical bonds, such tas the C-C and C-H bonds of candle wax, then there are fewer arrangements of atoms that will have the same energy concentrations. Having fewer eqivalent states means there is a lower entropy.

For instance, imagine a drawer full of red and blue balls. if they are arranged randomly, then you know that the concentration of red balls or blue balls per square foot is constant. Any random distribution of colored balls is thus equivalent, because they will all be (roughly) homogenous. However, if the blue balls are on one side, and the reds on the other, than only those arrangements of balls in which the colors are totally seperated are equivalent.

obviously you two have different deffinitions of entropy.

the crux of the matter is that while tmionman goes microscopically about it, thinking of particles and their sizes and energies, towander goes macroscopically about it, looking for patterns and order. the two are in fact reconcilable, or so i gather from modern math, but it takes an absolute heckload of math to do it. maybe you could both consider accepting the same approach so as to save the hassle ?

maybe the easiest way to do it would be dropping all discussion about entropy/entalpy and just focusing on the fact that order seems to be generated as a by-product of energy dissipation.

now let me ask you this, towander. is a vibrating chord alive ? presuming i keep feeding it energy. is iron dust on a working electric engine alive ? simply because something is ordered, or because it has periodicity does not make them alive does it ?

further more, is a black hole alive ? is an oil drop on water alive ? is a computer virus alive ? is traffic load on the internet alive ? (these questions are all serious, im not just flooding)

yea, the difference is mine is the correct one.

I would say those things are not alive…spontaneous formation of order is not enough to say something is alive. each of those things fails one or more of the 6 qualifications for life.

Indeed they are.


As you said, both approaches are equivalent. I won’t be drawn into an Is! Is not! kind of discussion. Therefore, a proof is required.

The concept of a local decrease in entropy in dissipative systems isn’t new at all. Prigogine received the 1977 Nobel Prize for his work in this area. None of this is new. A dissipative system arises to diminish an externally applied force and is thus a “transition state”. Both the classical (macroscopic) description and the statistical (microscopic) description of entropy are in line with these ideas, though as zenofeller said, this can be tough to prove. The theory of dissipative systems has been generally accepted, but it is “just” a theory. So I cannot prove to you, in a Platonic sense, that it is “true”. You’ll have to decide for yourself.

I propose to leave the flame alone and to focus, instead, on the enzymatic combustion of foodstuffs within the cell. In this case, it might look like this:

foodstuff + oxygen —> ENZYME-SUBSTRATE COMPLEX (net entropy change -20)
ENZYME-SUBSTRATE COMPLEX —> carbondioxide + water (net entropy change +120)

foodstuff + oxygen —> carbondioxide + water (net entropy change +100)

(This is, of course, simplistic because the enzymatic combustion consists of very many of such steps which are sequenced into metabolic pathways.)

I think none of these examples qualify as being “alive”.

I’m not sure if a virus is alive or not.

I think a candle flame is not alive.

I think that the currently accepted criteria for life are too limited, which allowed me to play the Devil’s Advocate in this discussion.

the enzyme example is a bad one for this discussion, because we are dealing with transition states of reactions that are not very well understood, and that occur over very short periods. The sorts of spontaneous order you are talking about are in much larger, much slower systems such as a flame or a convection current.

In any case, this is kindof a stupid arguement at this point. There are exothermic reactions which result in lower local entropy. I’m simply pointing out that in a candle flame, the molecules are getting smaller and hotter as the reaction progresses, leading to an increase in local entropy.

It’s a different arguement from my main point, that fire performs no moloecular catabolism. THAT is the real reason fire is not alive. The other debate is just clarifying the concept of entropy (between our “common” definition of entropy=disorder and the thermodynamic definition).

This discussion is very fascinating, but the argument over the definition of entropy is hindering our intellectual discussion.
I want to return to the main point of towander:

Maybe it is possible that the laws of nature wishes to move towards some end. By creating a “more efficient” manner converting energy, it may be able to ‘get more work done per unit time’ (efficiency). In essence, this would cause entropy to go up faster; however, a quicker transition to disorder allows a greater time for lack of action. Could the laws of our universe possibly wish to find some sort of stability in all this transition of entropy?

Could it be possible, that the reason for an increase in disorder is because our universe is expanding and our matter/energy is limited? And, ordered processes to produce disorder is merely natures mechanism to move towards its goal - the equivalent of using machinery to cut down trees rather than axes? -I gotta go read that book you recommended, the more I think about it the greater it stirs my curiosity.

Personally, I do not believe that a law “wishes” anything, nor that there is anything out there that “wishes” a particular outcome.

My personal motivation for my life-long study is to continue to be amazed at the richness and beauty of the many stunning phenomena in Nature. I have accepted the fact that I will never fully understand how Nature works. All I can do is to think about it, and to learn what others think, which in the long run makes me appreciate it all the more. I am an atheist, by the way.

A law is something thought up by humans in their quest for understanding. A law might have a “real”, “true” Platonic existance, but I don’t think we’ll ever get to the point where our theories, no matter how accurately they describe Nature as we see it, will ever be elevated to the the status of “Platonic truth”.

I do not know if the Second Law exists in the Platonic sense (i.e. discovery vs. invention). Us humans perceive a direction of time, this direction apparently being coincident with an increase of what we label to be “entropy”. I do not know why the Universe has entropy. I do not know why it increases. Those are descriptive properties: they describe, but do not explain. Explaining why the universe is the way it is, seems to be beyond us. Anthropic principle? Perhaps. That’s philisophy, isn’t it, and I don’t know enough about that to contribute to it.

Bénard cells, tornados and other non-chemical systems do not convert energy - they dissipate it. Such structures are a more efficient way to diminish the applied external forces. A chemical dissipitative system (usually a reaction-diffusion system) does convert energy: from work to other kinds of work, plus heat. A chemical system dimishes the chemical potential difference (i.e. the difference in chemical energy between reactants and products), which is the applied external force in this case.

As said, I do not know. It’s there, and I like to study its behaviour and how it relates to other processes that are there. The efforts made by science to understand the true origin of irreversibility (i.e. the arrow of time) are rooted so deep in quantum statistical mechanics that only a minute fraction of humanity has the ability to grasp what’s going on. And the issue is far from resolved - the jury’s still out there.

I’m very pleased that this discussion stirred your enthousiasm :smiley: ! That’s my main reason for writing about these things! That said, don’t spend money on a book until you know for sure that it has to offer what you’re looking for. Ball’s book describes many fascinating patterns that arise in Nature and offers equally fascinating explanations about how those patterns may arise. They range from beehives to the arrangement of spots on a leopard’s fur. This book does NOT, however, offer a detailed treatise on the origins of entropy. The book is also non-technical (no math). If you want to understand entropy better, then I recommend to start with Peter Atkins’ “The Second Law”.

Then, Ilya Prigogine’s “From Being To Becoming” (which is rather technical and out of print, BTW, but you might find it libraries) would be a good one. Another one, written at an undergraduate chemistry level, is the book Prigogine wrote with Kondepudi a few years back, shortly before he died: “Modern Thermodynamics: from Heat Engines to Dissipative Structures”. Prigogine also wrote a number of more philosophically inclined books, the best of which he did with Isabelle Stengers and is called “Order Out Of Chaos”.

so towander, other than just stirring enthousiasm for the workings of nature ( a very commendable thing) and pointing out shortcomings of current theories (a very worthy endeavour) might you be also interested in offering something of your own ? maybe an alternative deffinition for what is alive and what is not ?