Is fire necessary for technology?

[Moontanman]

I think can technology progress underwater has been asked before but what about advanced technology of higher than stone age or more advanced coming about in a non oxidizing atmosphere? If you can't have fire can you have anything more than stone age technology?

 

An example would if you had a super terrestrial planet with an hydrogen atmosphere could any life advance past the stone age since fire would not be possible in a reducing atmosphere.

[Buffy]

I think you have two questions here:

• Civilization possible without fire?
• Civilization possible in a non-oxygen environment?

The way you wrote it, it seems like your real question is the former.

 

So let's tick off the things that fire buys you:

• Heat if it's cold.
  
• Cooking if what you like to eat is hard to chew.
  
• Nice weapon against things that might want to eat you.
  
• Light to read at night by.
  

Is it possible that there are plenty of non-fire substitutes for these? Or that an environment might occur without the need for some of them?

 

I think the answer is yes, but I'll leave that for later in the thread....

 

You need a thneed! :phones:

Buffy

[Moontanman]

More to the point, is technology possible with out fire, stone tools would obviously be possible so would wearing animal furs but would anything more be possible? How do you get from stones to electronics with out fire? No steel i-beams without fire for sure and steel pretty much underpins our whole civilization.

[alexander]

i think it would be possible.... but not our kind of technology, because our technology is derived from heating, cooling, compressing, stretching, things we live by, but perhaps a technology of a different kind could be possible without fire, but only in a world radically different from our own...

[modest]

An example would if you had a super terrestrial planet with an hydrogen atmosphere could any life advance past the stone age since fire would not be possible in a reducing atmosphere.

 

I know it's off point, but fire should be pretty easy in a hydrogen atmosphere . Any reaction that liberates oxygen or chlorine would cause a flame in hydrogen if there were an ignition source. Here's an HCl flame, for example: http://upload.wikimedia.org/wikipedia/commons/1/1c/Hydrochloric_Acid_Burner_Flame.ogg.

 

On point, I don't think fire would be necessary. There are a lot of ways to make heat and copper is pretty malleable. Maybe it would seriously slow down development, but with clever enough people using clever chemistry and natural sources of energy I think some form of recognizable technology would get done.

 

~modest

[Moontanman]

One of the people of SETI was asked how he defined extraterrestrial intelligence, his answer was, any one who can build a radio telescope. (or something like that.

 

What sort of heat source would really be available to a creature who lived in a hydrogen atmosphere? I know flame is possible with out oxygen, a candle will burn in a chlorine atmosphere but how practical is that on a planet with no free chlorine?

 

Native copper on the earth is not exactly rare but amounts necessary for more than jewelry and ceremonial knives is not present without fire to get the metal from the ore.

 

I can imagine plants using sunlight to make oxidizers instead of sugars as food and when dry this plant material would burn in a hydrogen atmosphere but is this really practical, can biochemistry be turned completely upside down this way and give results that make sense? Would these oxidizers be stored and used like oil is here?

 

I still see no way for real technology to advance with out fire, barring some weird biochemistry how else could technology advance with out fire? I think this almost certainly indicates any technological alien civilization will be on an oxygen world, even if complex life can evolve without oxygen a technological civilization just wouldn't.

[CraigD]

Though speculating about some non-terrestrial biosystem with organisms capable of thinking of making human-like artifacts like fire-hardened spear tips, smelted metal, combustion engines and radio telescopes is, well, speculative, my guess is that regardless of atmosphere (or whatever medium our speculated technophilic beings live in), if the biology is sufficiently energetic to have metabolism capable of such thought, it would produce stuff that could be burned to produce useful heat and mechanical work, so its likely that any beings capable of burning stuff will have stuff to burn.

 

Note that, while we tend to ignore this potential because oxygen is so available in our atmosphere, typical biological materials is to some extent self-oxidizing – that is, wood, which is very roughly equal parts carbon, hydrogen, and oxygen, is not drastically chemically different from solid rocket fuel, which is the same stuff with nitrogen, chlorine, and typically a metal like aluminum added. So I imagine (very imaginatively) that technological folk even in a oxygen-poor medium would have some sorts of H + O + stuff -> HO + stuffO +energy reactions available to them.

 

Of course, it’s possible a smart/technological being might have a biology very unlike ours, in which oxygen was very rare, but even in this case, it must be getting the energy for its metabolism somewhere (nearly by definition, that without metabolism is not alive), so presumably could create some fire equivalent along the lines of that biology.

 

Other exotic possibilities for “fuel burning” intelligent life come to mind. For example, beings in an oxygen combustion-less environment with lots of concentrated radioactive stuff around might “rub stones together” to produce subcritical or even supercritical nuclear fission “campfires” many times more powerful than pre-atomic technology humans’ best.

 

High-power alien engineers might exist for whom fuel burning was rare or unknown. For example, beings with an affinity for optics in a bright environment might go about smelting and smiting with naturally occurring or artificial “big magnifying glasses”. Biologically astute alien engineers might build their technology around highly artificed biological cells, attaining in their prehistory a “wet nanotechnology” we humans yet only dream of.

 

These are just a few possibilities I can quickly imagine. Nature tends to realize energetic and structural schemes to shame human imagination.

[Moontanman]

Though speculating about some non-terrestrial biosystem with organisms capable of thinking of making human-like artifacts like fire-hardened spear tips, smelted metal, combustion engines and radio telescopes is, well, speculative, my guess is that regardless of atmosphere (or whatever medium our speculated technophilic beings live in), if the biology is sufficiently energetic to have metabolism capable of such thought, it would produce stuff that could be burned to produce useful heat and mechanical work, so its likely that any beings capable of burning stuff will have stuff to burn.

 

Are you saying that intelligent beings will be able to figure a way to create fire like reactions regardless of the atmosphere or that intelligent beings will only occur where there is an atmosphere capable of supporting energetic reactions?

 

Note that, while we tend to ignore this potential because oxygen is so available in our atmosphere, typical biological materials is to some extent self-oxidizing – that is, wood, which is very roughly equal parts carbon, hydrogen, and oxygen, is not drastically chemically different from solid rocket fuel, which is the same stuff with nitrogen, chlorine, and typically a metal like aluminum added. So I imagine (very imaginatively) that technological folk even in a oxygen-poor medium would have some sorts of H + O + stuff -> HO + stuffO +energy reactions available to them.

 

Craig, this is just not true, with out free oxygen wood is for all practical purposes inert. You can't get any energy out of wood in the form of fire with out oxygen. All the reactions you suppose require technology that is based at some point on fire. No aluminum, or chlorine or any other reactants would be available to primitives, all of the chemicals mentioned would require an exothermic energy source like fire at some point in their development.

 

 

Of course, it’s possible a smart/technological being might have a biology very unlike ours, in which oxygen was very rare, but even in this case, it must be getting the energy for its metabolism somewhere (nearly by definition, that without metabolism is not alive), so presumably could create some fire equivalent along the lines of that biology.

 

Hydrogen metabolizing microbes all ready exist on the earth, not to mention sulfur and a vast array of other life forms that do not need free oxygen, and their is at least one multicellular organism that does not metabolize oxygen so alive does not predispose an energetic metabolism. But an energetic metabolism does seem to need an oxidizer, it could be oxygen, chlorine, or fluorine but an energetic oxidizer seems to necessary for large animals.

 

 

 

Other exotic possibilities for “fuel burning” intelligent life come to mind. For example, beings in an oxygen combustion-less environment with lots of concentrated radioactive stuff around might “rub stones together” to produce subcritical or even supercritical nuclear fission “campfires” many times more powerful than pre-atomic technology humans’ best.

 

 

While true it seems far more speculative than a simple hydrogen breathing life form. Some restraints are necessary and i see no reason to postulate nuclear power being so available, in fact the cosmic abundance or lack there of uranium and other possible radio isotopes would seem to say it's so highly improbable as to be impossible. Far more improbable than a fluorine or chlorine atmosphere but since we talking no oxidizer in the atmosphere they are off the books too.

 

High-power alien engineers might exist for whom fuel burning was rare or unknown. For example, beings with an affinity for optics in a bright environment might go about smelting and smiting with naturally occurring or artificial “big magnifying glasses”. Biologically astute alien engineers might build their technology around highly artificed biological cells, attaining in their prehistory a “wet nanotechnology” we humans yet only dream of.

 

Big magnifying glasses? How do you get to optics with out fire to begin with? Glass takes fire to make and shape, no matter how advanced these aliens are at some point some sort of "fire" would be necessary for them to advance past flaking stone tools. Again, this is far beyond reasonable speculations, lots of clear optical glass lying around is much like native metals being so common that civilization could depend on them.

 

These are just a few possibilities I can quickly imagine. Nature tends to realize energetic and structural schemes to shame human imagination.

 

We can easily postulate hydrogen atmospheres, we can already see them in our solar system, microbes that live quite well with no free oxygen abound.

 

We could go further with silicon or silicone biology, even nitrogen phosphorus biology or boron biology but all of them suffer from how would complex animals evolve into technology with out fire, fire would seem to be the bottle neck beyond which can't go unless you carry fire with you.

[modest]

One of the people of SETI was asked how he defined extraterrestrial intelligence, his answer was, any one who can build a radio telescope. (or something like that.

 

What sort of heat source would really be available to a creature who lived in a hydrogen atmosphere? I know flame is possible with out oxygen, a candle will burn in a chlorine atmosphere but how practical is that on a planet with no free chlorine?

 

But you wouldn't need free chlorine. Chlorine gas burns with a flame in a hydrogen atmosphere, as does oxygen. So you would use something solid that decomposes fairly easily (at a low enough temp) releasing chlorine or oxygen gas. Perchlorates, for example, would be an excellent fuel source in a hydrogen atmosphere just like coal is here on earth, as would other chlorides, chlorates and oxides to various degrees.

 

Also, there's geothermal heat, friction, and any number of exothermic reactions that produce a lot of heat even if they don't make a flame.

 

Native copper on the earth is not exactly rare but amounts necessary for more than jewelry and ceremonial knives is not present without fire to get the metal from the ore.

 

Yeah, I see your point. But also the metal might be a lot easier to separate from its ore not being so oxidized.

 

I can imagine plants using sunlight to make oxidizers instead of sugars as food and when dry this plant material would burn in a hydrogen atmosphere but is this really practical, can biochemistry be turned completely upside down this way and give results that make sense? Would these oxidizers be stored and used like oil is here?

 

That's clever, and a good question. Maybe there are earthly examples of anaerobic respiration that store oxides. :phones:

 

I still see no way for real technology to advance with out fire, barring some weird biochemistry how else could technology advance with out fire? I think this almost certainly indicates any technological alien civilization will be on an oxygen world, even if complex life can evolve without oxygen a technological civilization just wouldn't.

 

I think you'd have a fair argument if there were no way to make fire except in an oxygenated environment. But, there may be naturally-occurring compounds that burn just like sulfur burns here on earth. I wouldn't rule out the possibility.

 

~modest

[Moontanman]

But you wouldn't need free chlorine. Chlorine gas burns with a flame in a hydrogen atmosphere, as does oxygen. So you would use something solid that decomposes fairly easily (at a low enough temp) releasing chlorine or oxygen gas. Perchlorates, for example, would be an excellent fuel source in a hydrogen atmosphere just like coal is here on earth, as would other chlorides, chlorates and oxides to various degrees.

 

Are things that decompose into oxygen and or chlorine likely on a planet that never had any free oxygen? Would they occur naturally in such large quantities they could be used routinely to make fire? or would they at least as rare as on the Earth or possibly even more rare than here due to lack of oxygen to make them?

 

 

Also, there's geothermal heat, friction, and any number of exothermic reactions that produce a lot of heat even if they don't make a flame.

 

 

Yes, but to make the things necessary to exploit these sources in a big way requires technology that was produced by fire.

 

Yeah, I see your point. But also the metal might be a lot easier to separate from its ore not being so oxidized.

 

That's possible but is the Earths oxygen atmosphere responsible for the oxides or were they oxidized by natural processes before free oxygen became available?

 

 

 

That's clever, and a good question. Maybe there are earthly examples of anaerobic respiration that store oxides. :phones:

 

As far as i know there are no natural examples of this, anaerobic reactions produce less energy than aerobic, it seems unlikely to me that anaerobic organisms would produce oxidizers, if they did they would be like plants using an outside source of excess energy.

 

I think you'd have a fair argument if there were no way to make fire except in an oxygenated environment. But, there may be naturally-occurring compounds that burn just like sulfur burns here on earth. I wouldn't rule out the possibility.

 

~modest

 

It has to be asked would such sources of reactants to hydrogen be produced by non biological processes in quantities to be anything more than curiosities like they are on the earth? Would sulfur burn in hydrogen? Would there be extensive deposits of such things on any world?

[alexander]

how about purely optical technology with no need for wires at all, so no need for melting, no need for fire, but other needs for sure, technology possible powered by some sort of a mineral that when submitted to a dose of something, like radiation, will emit light...?

[Moontanman]

how about purely optical technology with no need for wires at all, so no need for melting, no need for fire, but other needs for sure, technology possible powered by some sort of a mineral that when submitted to a dose of something, like radiation, will emit light...?

 

If these things do happen they are outside the realm of reality as we know it. Optics requires fire to make or at least technology that is based in fire.

[modest]

Are things that decompose into oxygen and or chlorine likely on a planet that never had any free oxygen?

 

Sure. Hydrogen compounds are abundant here on earth even though it has a hydrogen free atmosphere.

 

Would they occur naturally in such large quantities they could be used routinely to make fire?

 

I don't see why not. Like I said, I don't think you should rule out the possibility.

 

or would they at least as rare as on the Earth

 

But, chlorides and oxides are not rare on earth. They're everywhere. Some of them would burn quite well if earth had a hydrogenated atmosphere.

 

Also, there's geothermal heat, friction, and any number of exothermic reactions that produce a lot of heat even if they don't make a flame.

Yes, but to make the things necessary to exploit these sources in a big way requires technology that was produced by fire.

 

I don't think so. Technology that was produced by geothermal heat, for example, could be used to exploit geothermal heat in a big way.

 

 

That's possible but is the Earths oxygen atmosphere responsible for the oxides or were they oxidized by natural processes before free oxygen became available?

 

Probably both.

 

It has to be asked would such sources of reactants to hydrogen be produced by non biological processes in quantities to be anything more than curiosities like they are on the earth?

 

Given that oxygen and chlorine are such abundant elements in the cosmos, I don't see how you could rule out the possibility.

 

Would sulfur burn in hydrogen?

 

No, but a chloride of sulfur sure would.

 

Would there be extensive deposits of such things on any world?

 

I honestly don't see why not.

 

~modest

[CraigD]

Are you saying that intelligent beings will be able to figure a way to create fire like reactions regardless of the atmosphere or that intelligent beings will only occur where there is an atmosphere capable of supporting energetic reactions?

I’m speculating – “saying” or “claiming” is an overstatement – that an environment that supports metabolism will biologically produce material with chemically stored energy that can be released in ways other than its normal biological metabolism. For brevity and to analogy, let’s call such material “wood”. Nearly all biological systems we’ve seen or imagined store energy chemically.

 

In short, what I’m saying is:

• Any environment that supports powerful biological metabolism will generate “wood”
  
• Intelligence as we know it requires powerful metabolism, so where there’s intelligence, there’s likely to be wood
  
• Wood can be burned – that is, somehow, the hydrogen in it can be combined with oxygen to release energy.
  
• That the oxygen required must come from an atmosphere is not a strict requirement, but a preconceived conclusion driven by our Earthly experience
  

Craig, this is just not true, with out free oxygen wood is for all practical purposes inert. You can't get any energy out of wood in the form of fire with out oxygen.

I’m out on a limb here, and may be, as you believe, wrong no matter how farfetched my speculative assumptions about an imagined alien biology, but I’m guessing that you actually can burn ordinary wood in a completely oxygen-free atmosphere.

 

Notice that wood, which is essentially large lignin molecules and fibrous cellulose, contains a lot of oxygen in a higher energy state than [ce]CO_2[/ce] and [ce]H_2O[/ce]. What happens ordinarily when wood burns is that (via a processes called pyrolysis) an external heat source breaks the wood’s weak bonds, releasing tar (primarily [ce]C_6H_{10}O_5[/ce]) which in turn releases gases like [ce]C_nH_{2n+2}[/ce] (hydrocarbons) and [ce]C_6H_5OH[/ce] (phenol). The hydrocarbons and phenol combine with [ce]O_2[/ce] from the surrounding air – that is, burn – releasing energy and producing [ce]CO_n[/ce], [ce]H_mO[/ce], and carbon waste.

 

My big speculative leap is that small amounts of free oxygen are released via pyrolysis, so that a much-smaller-than-with-ordinary-fire portion of the hydrocarbon gas could burn via this oxygen, in the absence of any external supply, but not so much smaller that the net reaction wouldn’t still be exothermic. Very roughly, this is what solid rocket fuel does, and does much better (for which I’m glad, because if all wood was rocket fuel-ready explosive, the world would be a hellish place ;)) because of it’s higher oxygen to hydrogen ratio, and its more easily liberated oxygen.

 

My next speculative leap, which I didn’t directly state in my previous post, is that alien wood, especially during decomposition, might contain extra oxygen-binding molecules like [ce]C_6H_7N_6O_{11}[/ce] (nitrocellulose) or [ce]H_4N_2O{3}[/ce] (ammonium nitrate), making it chemically more rocket-fuel like.

 

I’m really just trying to jar the reader into questioning preconceptions about familiar wood-burning processes, and show how ordinary wood-burning and rocket-firing are not entirely dissimilar, but points on a continuum of chemical reactions that might – in an alien environment, include external oxygen free “wood” burning..

 

:( I worry that, in keeping my speculation so close to the chemistry of ordinary terrestrial wood durning, I’m inappropriately narrowing what we should consider “fire” in this thread’s context. In an alien environment, our terrestrial practice of buring biological products – wood – may be irrelevant. Some surprisingly simple chemistry can produce energetic reactions – for example, finely milled aluminum powder in water.

 

(A good summary of the details of wood burning can be read at the aptly named webpage “Burning of wood”. An interesting aluminum-water ice reaction was recently demonstrated in a small ALICE propelled rocket)

[Moontanman]

All i can say is you need to read your own link, wood does not release energy unless it burns with an external oxidizer. Heating wood to release it's constituent chemicals takes energy with out an oxidizer it does not release any energy.

 

I think any other "wood" would be the same way, stored energy is released only if an external oxidizer is present. Rocket fuel, besides being an unstable mixture, takes more energy to make than it releases, wood is not unstable, it is inert except for when it is exposed to an oxidizer and a heat source, it takes an external heat source to cause wood to burn. With no external oxidizer all you get is out gassing of chemicals that do not react with each other and absorb energy.

 

As for the aluminum, how do you get the aluminum? What you are talking about is no better than using the alternator of your car to produce hydrogen to make the engine turn the alternator. Breaking aluminum out of it's compounds takes far more energy that you can get by burning it, it also takes technology already based on fire.

 

Modest, I would also think that oxidizers would not tend to accumulate in a hydrogen atmosphere world, just as hydrocarbons do not accumulate in an oxygen atmosphere, the hydrocarbons of our world are made by biology.

 

I would like to see some idea of what you are talking about when you say large deposits of oxidizers that would "burn" in a hydrogen atmosphere.

 

 

I would like to say that plants on a hydrogen world making oxidizers instead of sugars and having tissues that are oxidizers does sound reasonable, i just can't wrap my head around how that would work.

[Moontanman]

Ok, I have a take on this I wish to share.

 

First, modest, you threw me, i hadn't thought of natural deposits of oxidizers but i am still betting that they would be too few to support primitives around a campfire much less any technological civilization, in the same way that virtually all hydrocarbons on the earth have at their basis biology...

 

Craig, you came very close to saying what has been rattling around in my brain.

 

Here is what I think about it.

 

First large complex animals predisposes a source of energy beyond anaerobic respiration. In saying intelligent life, everyone centered on animals and what they need but like me everyone ignored that a biosphere of complex life included plants and plants are aerobic too. Plants above the microscopic, and most of them as well, require oxygen just like animals. Put a plant in an enclosed place, give it plenty of light, water and CO2 but take away the oxygen faster than it can produce it and the plant dies.

 

Plants store energy in the form of carbohydrates and use oxygen to release the energy they store. plants "eat" those stored carbohydrates just like animals do. Plants use oxygen to metabolize those stored carbohydrates just like animals do. In the dark plants need oxygen.

 

On a planet with a hydrogen atmosphere it would make no sense for plants to store carbohydrates for energy because they would have no oxidizer to use them to produce energy. you might get photosynthesis but not large complex plants.

 

Animals that ate the plants carbohydrates would have no way of obtaining energy from them like the reactions here on earth that allow carbohydrates to serve as energy storage.

 

If you assume complex animals then it follows that on a world with a hydrogen atmosphere the plants would use sunlight to make oxidizers to store energy instead of carbohydrates. plants would take up methane and water and use sunlight to make oxidizers and release hydrogen (in the presence of light) animals would eat the oxidizer plants and breath in hydrogen and exhale methane.

 

So it is not hard to imagine dry plant tissue full of oxidizers burning in the hydrogen atmosphere when heat is applied much like the earth except the exact reverse of what occurs here.

 

BTW Alex, i like atomic powered robots tooo:hihi:

[modest]

I would like to see some idea of what you are talking about when you say large deposits of oxidizers that would "burn" in a hydrogen atmosphere.

 

You don't need to put burn in quotes.

 

From these experiments, we perceive that combustibility and combustion are only relative phenomena; if hydrogen is combustible in chlorine (or air), so, inversely, is chlorine (or air) combustible in hydrogen. The term combustion, in chemistry, is understood as every chemical union of a body with a gas, which is accompanied by the phenomenon of light.

 

A text-book of inorganic chemistry - Google Books

 

I don't have a list of compounds that burn in a hydrogen environment or any thing like that. Offhand, I would guess that chlorides do not, but most chlorates and all perchlorates do. Some nitrites and most nitrates (depending on the boiling point or the temp. of decomposition). The same thing with sulfites and sulfates. A couple specific examples would be potassium, sodium, or ammonium nitrate and potassium, sodium, or ammonium perchlorate.

 

Such things are abundant on earth. I don't know if they would be abundant on a planet with a hydrogen atmosphere or not, I was just saying that one shouldn't rule out the possibility. Nor to rule out the possibility that an intelligent life form could make use of them.

 

If you assume complex animals then it follows that on a world with a hydrogen atmosphere the plants would use sunlight to make oxidizers to store energy instead of carbohydrates. plants would take up methane and water and use sunlight to make oxidizers and release hydrogen (in the presence of light) animals would eat the oxidizer plants and breath in hydrogen and exhale methane.

 

So it is not hard to imagine dry plant tissue full of oxidizers burning in the hydrogen atmosphere when heat is applied much like the earth except the exact reverse of what occurs here.

 

I like the idea.

 

On the animal front, the anaerobic respiration wiki page gives as an example:

glucose + 3SO

₄

^2-

+ 3H

⁺

-> 6HCO

^3-

+ 3SH

 

If the organism stored large amounts of sulfate then that would be an excellent fuel.

 

~modest