Is fire alive

[errandir]

I am unclear about what it means to be "alive." Is fire alive? What are the criteria that fire satisfies to make it so? Or, what criterion for being alive does it violate?

[Pete]

The definition of life is a fuzzy one.
I think that in practice, life is defined by it's members, rather than by any precise criteria (ie whether something is alive or not is arrived at by consensus rather than directly by objective analysis).

Is fire alive?
It consumes chemical energy from raw materials (eats)...
It consumes oxygen (breathes)...
It reproduces...
It dies...

The last two are a bit suspect, however.
Does fire really reproduce? Does a "child" inherit properties of the "parent"?
What does dead fire look like?

[perfectblue]

A dead fire looks like carbon.

[Pete]

That would be a partly burnt stick. It was never fire; it is the remains of the fire's fuel(food).

Ash is to fire as excrement is to animals.

[SG-N]

I thought that water was needed for "life"... but I can't choose if I will say "yes" or "no" to this interesting question! :eek:

[Redoubtable]

The Seven Traits of Life

Sensitivity and reactivity to the environment and Capacity for adaption
Ingestion of substance for energy to function
Reproduction
Respiration
Emission of wastes
Internal Movement
Cellular Structure


Fire is not alive.
Fire is a chemical reaction, a rapid oxidization, that happens to make invisible gases glow with thermal energy transmitted by conduction and convection.

[Nasor]

It's important to remember that there's no fundamental difference between living and non-living matter. Whether or not we choose to categorize something as 'alive' is completely arbitrary.

[Mucker]

Have you been watching backdraft Errandir?? :D

No fire isn't alive, because 'life' has a free will (in most people's definition).

[Pete]

So plants have free will now?

[Redoubtable]

LOL

[lifegazer]

Originally posted by Redoubtable
Sensitivity and reactivity to the environment and Capacity for

Here you say that sensation or awareness (of sensation) is a trait of life.
Your following quote denounces the fact that a mere physical-process can be equated to life:-

Fire is not alive.
Fire is a chemical reaction, a rapid oxidization, that happens to make invisible gases glow with thermal energy transmitted by conduction and convection.
So, how do you reconcile the two statements? On the one hand you say that a physical process is not life. And in the second hand, most here would say that physical processes are the cause of life.
If this is the case, then life is a mere physical-process, which means that there might be life in fire.

[Mucker]

No Pete, that's why I said 'life' has a free will (in most people's definition). I would say most people do not class plants as *living, hence a pre-definition for live is free will.

*Edit: Sorry, I didn't mean non-living.

[Pete]

Mucker, you're not making sense.

Plants have no free will.
Plants are alive.
Therefore, having free will is not a necessary condition for being alive.

Where's the problem?

[Nasor]

You might be able to make a good argument for fire being alive. At the most basic level, living things like plants and animals are just self-sustaining chemical reactions, much like fire. Of course the chemical reactions that allow plants and animals to exist are far more complicated then the relatively simple reactions involved in combustion, but they are both reducible to self-perpetuating reactions.

This is why fire shares so many of the characteristics of life commonly accepted in biology; fire reacts to the environment, ingests substances for energy to function, reproduces, respirates, emits wastes, and has internal movement. The 'cellular structure' requirement was more or less tacked on arbitrarily so that we wouldn't have to consider fire to be alive.

[Mystech]

Well what exactly is fire? If we're just talking about the flame then that's nothing more than superheated gas. If we talk about the chemical reaction, that's just a process which is taking place within the molecules of another object, be it wood, or hair or whatever.

[phlogistician]

Originally posted by Mucker
Have you been watching backdraft Errandir?? :D

No fire isn't alive, because 'life' has a free will (in most people's definition).

Mucker, there's no such thing as 'free' will. Everything is random chance, or determined outcome, affected by many factors, from chemical reactions, gravity, and quantum menchanics. We have no choices, just possibilities.

[SG-N]

I was about to say : "Cellular Structure! That's the solution. Thus fire is not alive!", but I thought about AI. If we agree that "Cellular Structure" (biological) is life, then we say that a robot with an AI (in 10000 years) will not be alive. Here, I disagree!

Thus, the problem is still open for me. :(

[Absane]

Perhaps if we can somehow prove evolution to be true, this would imply that fire is not alive, because it never evolves.

[SG-N]

Does everything evolve? (bacteria)

[river-wind]

while it is generally agreed that fire isn't alive, this is one of the most common examples of why our simplification of "what is life?" isn't the most accurate. the second most common example is that Viruses and priors aren't technically alive by the formal definition, though they certainly seem to act like they are alive.

The Seven Traits of Life

Sensitivity and reactivity to the environment and Capacity for adaption
Fire reacts to changes in it's environment. it moves when wind blows, it changes color when it's fuel is changed. it burns in spheres in zero gravity.

Ingestion of substance for energy to function
Fire externally (sort of) ingests fuel, and uses it to survive. whent he fuel runs out, the fire 'starves' and goes away.

Reproduction
fire can move from one fuel source to another via wind or heat transfer, you end up with two flames instead of one.

Respiration
fire uses oxygen in it's reactions, and therefore respires.

Emission of wastes
fire gives off water and ash as it's products in most cases.

Internal Movement
ever watch a fire burn? it certainly has internal movement.

Cellular Structure
nope.


The main rub seems to be that fire doesn't have a cell membrane of some kind. But then again, neither do viruses or prions, really. there isn't a diffinitive boarder which seperates the fire from it's surroundings. it is really not a thing, but a different state of it's surrounding medium (hotter air/gas than the non-flame near it).

However, if you look close enough at cell membranes, they are just a high consentration of their surrounding material. lipid bi-layers will slef assemble in solution, but a beaker with proto-cell membranes floating in it isn't alive. Look even closer, to the atomic level, and most of everything is empty space, so where is the clear dividing line between what is inside the cell and what is out? there really isn't one.

[Absane]

Originally posted by SG-N
Does everything evolve? (bacteria)

In theory.. couldn't bacteria have evolved to other forms of life.. eventually to humans (again.. all in theory)?

[Redoubtable]

Originally posted by lifegazer
Here you say that sensation or awareness (of sensation) is a trait of life.
Your following quote denounces the fact that a mere physical-process can be equated to life:-
So, how do you reconcile the two statements? On the one hand you say that a physical process is not life. And in the second hand, most here would say that physical processes are the cause of life.
If this is the case, then life is a mere physical-process, which means that there might be life in fire.

The one trait "sensitivity and reactivity" is not the same as awareness. Also, that characteristic alone cannot qualify a potential organism as living; all seven traits must be exhibited. Simple chemical reactions, like fire's rapid oxidization, are not necessarily alive.

[wesmorris]

Just to be a crackpot:

I think that there is a force that I call "the life-force" that is the motivator behind life. In other words, there seems to me to be a force that makes things come to life under certain conditions. Fire is not a resultant of this force. As such, it is not alive.

[errandir]

Originally posted by Mucker
Have you been watching backdraft Errandir??Well, actually, I've never seen this movie. It just seems strange that we classify utterly countless different objects as alive, and it seems so obvious to me that certain objects are not alive. But, then again, I don't even know how to tell if another human is dead or alive. There are comas and such that seem very death-like to me, but, mysteriously, sometimes people will wake right out of them. Do the dead come back to life so readily? I doubt it, but maybe. The virus is the most contraversial fence-sitter, IMO, but, I thought fire would be a nice simple testing ground for the definition of life. I've asked people this question for years, but they would give me an unsatisfyingly terse response (invariably "no"), and then, they would get agitated when I tried to discuss it with them (or simply disinterested). The responses I've seen so far are EXACTLY the kind of rhetoric and discussion that I was looking for.

Y'ALL are all great. Thanks a million.

[errandir]

Originally posted by SG-N
Does everything evolve? (bacteria) I'm not sure I know what you mean, but there is some sort of evolution on an extremely accelerated scale when it comes to germs. When the doctor gives you antibiotic ("bio" refers to life, if that's not a gimme), you had better follow the instructions, or else, the germ could mutate (evolve) into a form that is resistant to the medication.

[errandir]

I think the issue might be that our "definition" of life isn't really a definition, but an attempt to condense a shit load of info into a few sentences.

I think we start by saying that <i>we</i> are alive. Then, we get a touchy-feely idea of what is life, and we attribute it to certain animals. Then, plants, we say, are also alive, stretching the idea of life to encompass other objects and making ourselves feel less alone. At this point, we should stop and ask, not, "what is life," but, "what is a plant." Which is the stronger definition? "All plants are alive," or, "it is NOT a plant, if it is not alive."

[Mucker]

Have you been watching backdraft Errandir??

...Well, actually, I've never seen this movie. Who said it was a 'move-ee'? It's a television show :D

Plants aren't alive: they have no choice of movement (a will that is free)

Thus fire is not alive because it has no choice of movement.

[Nasor]

Originally posted by Redoubtable
The one trait "sensitivity and reactivity" is not the same as awareness. Also, that characteristic alone cannot qualify a potential organism as living; all seven traits must be exhibited. Simple chemical reactions, like fire's rapid oxidization, are not necessarily alive. Plants aren't 'aware' of their environment in any sort of conscious way, but they react to their environment and the vast majority of people would consider them to be alive. All of the 'seven characteristics of life,' with the exception of the cellular structure requirement, are merely traits of ongoing chemical reactions. Both your own body and fire are conglomerations of chemical reactions that are playing themselves out. The only difference is that the reactions which allow you to live are far more complex than the reactions involved in fire.

[Pete]

I would say most people do not class plants as living
...
Plants aren't aliveMucker, you would say wrong.
By common convention, plants are alive.
Ask anyone. Go on! Ask the nearest person, see what they say. Start a poll if you like.

[Angelus]

Imagine if what we think of as ourselves is really just one single cell that recieves all the sensory input. A king cell that controls all the others. Maybe it's even the original zygote.

[Absane]

Originally posted by wesmorris
Just to be a crackpot:

I think that there is a force that I call "the life-force" that is the motivator behind life. In other words, there seems to me to be a force that makes things come to life under certain conditions. Fire is not a resultant of this force. As such, it is not alive.

If there is a such "Life Force," how can you conclude that it does not result in fire? You only said it makes things come to life, and because the life force is not affecting fire, fire is not alive.

What about spontaneous combustion? Maybe a person received too much life force? :p

[and2000x]

In theory.. couldn't bacteria have evolved to other forms of life.. eventually to humans

Yeah, it could have, but IT DIDN'T. For example, blue algae is theorized to be the first life form on this planet and it still exists today in the same form as fossils from 10mya or 600mya.

Since life is composed of and consumes inorganic materials and the fact that life sprung up from inorganic materials would mean that life and nonlife would carry very common traits. Every particle in the universe is on a mission to duplicate itself, every reaction, every chemical, every thing duplicates. Every process uses energy and produces waste.

If you can't follow the criteria, the seven traits, then the term life is baseless and I am as alive as this keyboard. Life is defined by the cellular and anything else is a semantical question. I have pondered the virus question too, and there is a possibility that there are beings composed of completely different forms of energy (like Silicon or pure radiation or something as absurd). For now the definition sits under the seven traits.

[wesmorris]

Originally posted by 4DHyperCubix
If there is a such "Life Force," how can you conclude that it does not result in fire? You only said it makes things come to life, and because the life force is not affecting fire, fire is not alive.

What about spontaneous combustion? Maybe a person received too much life force? :p

as a generality i would conclude as such because fire is not born of seed or womb. Well, that and that fire itself is not of substance, but the label of a common chemical reaction. things that i generally consider "alive" are the result of a chemical reaction rather than the reaction itself.

[and2000x]

generally consider "alive" are the result of a chemical reaction rather than the reaction itself.

Whoa, good point. Perhaps your fake idea has some merit.

[wesmorris]

Originally posted by and2000x
Perhaps your fake idea has some merit.

Hey, it's a real idea. The merit part is the question though eh?

[khallow]

Originally posted by Redoubtable
The Seven Traits of Life

Sensitivity and reactivity to the environment and Capacity for adaption
Ingestion of substance for energy to function
Reproduction
Respiration
Emission of wastes
Internal Movement
Cellular Structure


Fire is not alive.
Fire is a chemical reaction, a rapid oxidization, that happens to make invisible gases glow with thermal energy transmitted by conduction and convection.

There's a couple of comments I want to make here. First, reproduction doesn't have to be a trait of life. Ie, the last suriviving member of a species that reproduces via sex is still alive even though it no longer can reproduce (needing a nonexistent partner).

But for life that does reproduce, it appears to be ultimately self-propagating information. Eg, the human body ultimately is a vehicle to transport 30,000 or so genes and maybe those genes in turn are present in order to propagate a bunch of symbiotic (but perhaps occasionally parasitic since they may be able to morph into viruses) DNA snippets.

The key to self-reproducing information, is that the information must have a way to alter its environment in a way that can improve its chances of propagation. In terms of genes, the gene must be able to "express". From the analogy with genes, if information can't express itself, then it will disappear: overwhelmed by environmental processes, get consumed by information that can express, or collect errors until it is no longer recognizable.

Thus, in this sense, computer viruses and worms are alive. They just happen to live in an artificial environment where information can express very easily. Prions are another example of reproducing life in this sense. They are certain proteins that encode a deviant structure which can propagate itself in the presence of appropriate unaltered proteins. Finally, memes (in the incorrect, weaker Internet sense of self-propagating ideas) can be alive since they are information which propagates itself in the minds of human beings.

[Redoubtable]

Originally posted by khallow
There's a couple of comments I want to make here. First, reproduction doesn't have to be a trait of life. Ie, the last suriviving member of a species that reproduces via sex is still alive even though it no longer can reproduce (needing a nonexistent partner).


In this sense, the term reproduction indicates the procreative capability of the entire species. The traits I provided are to be used in the judgment of a fully represented species, not an individual.
In a sexually reproductive species, if there were to be only one member of one gender remaining, the species would be, for all practical purposes, extinct. Without the ability to reporduce, the group is already dead.

[khallow]

Originally posted by Redoubtable
In this sense, the term reproduction indicates the procreative capability of the entire species. The traits I provided are to be used in the judgment of a fully represented species, not an individual.
In a sexually reproductive species, if there were to be only one member of one gender remaining, the species would be, for all practical purposes, extinct. Without the ability to reporduce, the group is already dead.

One of the scenarios I was thinking of when I wrote my article, is what happens if you had for example an intelligent machine built for a single purpose (as a space probe) or perhaps explicit designed so that it wouldn't reproduce nor even change much in its overall design (ie, to further prevent the chance of a von neuman self-reproducing machine). These machines would likely be considered alive by most people. Further, we might discover or build reproducing life that has no obvious speciation.

My point is that we have significant trouble even in determining what is alive on Earth within our limited sphere of understanding.

As an aside, there's another interesting point. Namely, if for some reason, self-replicating information became the standard for life or just merely valuable in its own right, then how important is it to prevent extinction of self-replicating information and perhaps even aid the propagation and evolution of this?

For example, virtually all life contains variations of genetic information that dates back perhaps more than a billion years collectively. Further, even with human interference, we are seeing evolution of organisms in action (human interference is increasing greatly the rate of evolutionary change due to our mass alteration of ecologies, but that's a different story). And a lot of organisms seem to be at some degree of presentience though not necessarily close to humanity. For example, primates, Cetaceans, octopi, other large mammals, and social insects. Finally, these organisms apparently evolved from scratch. Ie, we have a billion years of evolution, very elaborate creatures, all coming from relatively simple organic compounds. I would assign this an extremely high value.

On the other extreme, a computer virus may have some inherent value as a crude life form. A sophisticated one would probably be able to achieve most of your criteria for life (obviously not the physical characteristics like having cellular structure or consuming energy though they do consume analogous resources, eg, CPU time, memory, and connectivity access). However, it wouldn't have the same value as say bacteria, because it's the product of a few days or weeks of work, has a collective life span (ie, it and all its progeny) measured in months or perhaps a few years, and finally has no potential since the systems it infects are likely to become obselete in a few years, and of course, it's invariably costly to society to manage. Archiving them in a inert digital form seems a reasonable thing to do though.

So there seems to be a host of considerations for what to do with a lifeform (even using a liberal definition of "life"). How long has it and its ancestors lived? What environment is it adapted to? Does it cause harm? What potential does it have? These seem a good start to determining how valuable a particular lifeform is.

[Ender]

Its not alive because if you put a bullet through it id doesn't die.

[SG-N]

Originally posted by Ender
Its not alive because if you put a bullet through it id doesn't die.
LOL... Have you ever killed a giant tree with a bullet?

[khallow]

Originally posted by Ender
Its not alive because if you put a bullet through it id doesn't die.

Also, you can kill a computer virus by shooting the hard disk and the CPU of computer on which the virus resides. Boy, I've been tempted to do that some days for reasons completely unrelated to computer viruses. Second, you can theoretically kill an idea by shooting the people who have that idea (though that may be most of the population).

[and2000x]

The computer argument would require a new meaning of the word life. Since life is defined by these traits, how could it be any other way? A computer might somehow become a conscious fully aware being, but if it lacks any of these traits it doesn't count. A good scientists shouldn't have to tackle semantics so much.

[khallow]

Originally posted by and2000x
The computer argument would require a new meaning of the word life. Since life is defined by these traits, how could it be any other way? A computer might somehow become a conscious fully aware being, but if it lacks any of these traits it doesn't count. A good scientists shouldn't have to tackle semantics so much.

A scientist good or not often has to tackle semantics. And in my case above, the assertion was that something was "alive" if you couldn't kill it with a bullet. In my defense, I was pointing out that his criteria wouldn't filter out the things I mentioned.

As far as the traits of life go, I have only seen one really credible argument put forth. Namely, that something is alive if it exhibits these traits:

1. Sensitivity and reactivity to the environment and Capacity for adaption
2. Ingestion of substance for energy to function
3. Reproduction
4. Respiration
5. Emission of wastes
6. Internal Movement
7. Cellular Structure

The problem with this list is that it's oriented towards discerning Earth-based organic life. In particular, items 2, 4, 5, 6, and 7 need not be apparent in a life form IMHO. Partly, this is because the environment for a living being need not be as harsh as it is on Earth. The five traits I note are all necessary in order to maintain an internal environment for the genetic data and protein chemistry common to Earth-based organic life. Ie, the semantics of "life" is a core problem here because of our limited experiences with cases that test the limits of the "alive"/"not alive" criteria.

An extreme example is cities. These exhibit all the traits mentioned above (IMHO of course). What makes cities alive or not alive?

In a software environment, the environment make take care of these needs for you. You don't need to ingest any sort of substance, the environment is fed energy and runs your processes for you. You don't need respiration or cellular structure because you aren't a physical entity. Your internal state can and probably would change, which probably isn't quite the same as saying that there's internal movement. Waste elimination might be relevant since a program with a high degree of memory, would probably need to throw away old data or perhaps fail to pass on old data to the next generation (so that the old data is deleted when the program is). And the program can achieve both characteristics 1 and 3 very easily.

One key thing here, is that I'm talking about the program not the computer. The computer may or may not be considered part of the program. The latter can occur particularly if the program can hop from one machine to another, or is distributed over a number of machines. OTOH, the program may be married to the machine in which case it is reasonable to categorize both program and machine as a whole and hence simultaneously "alive" or "not alive".

[patty-rick]

firstly dead fire beign carbon thats kinda stupid, carbon isnt the only thing that burns fire can exist in an environment with out fire,
as for being alive, well u just need to define alive, some will define living to include fire somewhat, living i dont think can be defined, im sort of pessimisstic, but i am as alive as a rock, though its functions as a 'rock' are much more limited than mine, my more technical chemical and elemental make up means that i am capable of more 'interactions' some people classify this as alive, the problem with classifying this as alive is where to draw the line on a scale of 'alive', im a made of matter a rock is made of matter, my body is designed to manipulate other matter, through a variety of mediums, i am still only matter

[errandir]

I am curious from whence has this list of the seven traits of life originated.

I regret ever posting this thread. I now see how arbitrary, irrelavant, and academic it is.

[Redoubtable]

Many biology textbooks use those seven traits or variations thereof to differentiate between the living and the nonliving.

[khallow]

Originally posted by errandir
I am curious from whence has this list of the seven traits of life originated.

I regret ever posting this thread. I now see how arbitrary, irrelavant, and academic it is.

That's too bad since this was my favorite thread since I joined recently.

I'm not sure where the seven traits of life list came from, but I've seen it in a couple of places where they were trying to scientifically define and discuss Terran life.

I think part of the problem is that we have very little experience with life. This probably will change over time.

[errandir]

My point was that a definition doesn't yield any insight, at least, not to me. Save it be insight into the fundmental thoughts of my fellow man. I suppose that is interesting in itself, just not to me.

[Morteza Olangui]

Hi
To be or not to be that`s the question.
Thanks

[khallow]

Originally posted by errandir
My point was that a definition doesn't yield any insight, at least, not to me. Save it be insight into the fundmental thoughts of my fellow man. I suppose that is interesting in itself, just not to me.

In a sense, we are playing with semantics. There's are categories of objects that are usually considered alive (sentience, animals, plants, etc), and not alive (cars, rocks, fire, etc). For the sake of communication, we should have some agreement on what life is and generally we do. In theory, one could just make up a list of things that are alive or not alive. That master list would be the definition of "life".

The question isn't really "what is life?" but rather "What is a simple definition of life?" We want to make the definition of life simple. That's where it gets hard and why we need to consider examples like fire.

Definitions of life can matter a great deal. For example, US law encodes a degree of protection for life forms via acts like the Endangered Species Act. Being legally recognized as alive might be a significant change in legal status. The definition becomes important.