Monday, 10 August 2009

Chemical History Of A Candle


I SEE you are not tired of the candle yet, or I am sure you would not be interested in the subject in the way you are. When our candle was burning we found it produced water exactly like the water we have around us; and by farther examination of this water we found in it that curious body - hydrogen....

There is no better, there is no more open door by which you can enter into the study of natural philosophy than by considering the physical phenomena of a candle.

--Michael Faraday

There's an experiment where a lighted candle stands on a dish of water. A glass jar is placed over the candle. Eventually the candle extinguishes, and the water in the dish is pulled inside the jar. This mostly happens just after the candle flame has gone out. When the candle is alight it causes the side of the glass to become misty - steamy. Once the air cools as the candle goes out, water vapour condenses on the side of the jar, and appears as drops of water.

This site offers a real good explanation of the experiment:
http://www.wonderquest.com/candle-out.htm

Or you can watch it here:
http://www.metacafe.com/watch/893143/candle_and_water/

The wax of the candle is actually formed of carbon and hydrogen and so is called a hydrocarbon. Most fuels including petrol and coal are hydrocarbons. During the process of burning the carbon combines with the oxygen of the air and forms carbon dioxide. Hydrogen in turn combines with oxygen to form water vapour. It is not the solid wax, nor the melted wax, nor the wick which burns when a candle is lit. In fact, what is burning is a vapour or gas.

The amount of water being pulled into the glass occupies about one-fifth of the volume. Supposedly, the water has replaced the oxygen which was burnt inside the glass. It is for this reason that we are taught that air contains one-fifth oxygen.

One thing to remember though is that oxygen does not burn. Oxygen inside the glass does not burn. Since oxygen does not react with oxygen it cannot burn. Only the fuel "burns". For example carbon is a fuel and will react with oxygen (oxidizing agent) to form the new compound, carbon dioxide. If the oxygen really was being burnt then we would expect to see the water rise gradually - it doesn't. It's a very rapid rise after the candle goes out.

The air inside the glass gets hot. The outer core of the candle flame is known to reach temperatures of 1400 degrees C. It gets a bit steamy. We have hydrogen gas being released by the candle. I don't think it's simply a hydrogen atom bouncing around. I think it is a small hydrogen atom being released from the candle, and expanding into a large atom of hydrogen gas. Here, it reacts with the oxygen in the air, and forms water vapour. This reaction is known to produce intense heat.

When the candle goes out the air cools. The water vapour condenses on the side of the glass. The water in the dish is then pulled up into the glass. We are taught that "nature abhors a vacuum", and I think there is a ring of truth to this. Nature - and you don't get any closer to the very nature of the Universe than the electric fluid of the aether - abhors a vacuum. The aether much rather prefers equilibrium.

At this stage I would like to summise that water vapour inside the glass is turned into liquid water. As a vapour, water occupies a lot more space than as a liquid - some 1700 times more. A water vapour molecule could therefore be some 1700 times bigger than a liquid water molecule. Once the water vapour is taken from the air and condensed into water - it's going to leave quite literally nothing behind. What then is going to fill that space which is left? Why water from the dish of course!

Air displaces water. In accordance with Archimedes principle, the amount of water displaced depends on the mass of that object (not the weight). The water sucked from the dish into the glass is replacing something which occupied the same mass. Mass is the amount of material in an object. The water sucked into the glass takes up roughly one-fifth of the volume inside the glass. Is it possible then that the water which has condensed on the side of the glass once occupied one-fifth of the volume as water vapour? Does air consist of one-fifth water? In a previous post I suspected that the air IS water vapour - does this still apply?

Hydrogen burns with a mostly invisible flame. Pure hydrogen-oxygen flames, as used by some rockets, emit ultraviolet light and are nearly invisible to the naked eye. If you look at a candle flame, you will see nearest the wick, the flame is nearly invisible. A candle flame, though sadly this is hardly ever mentioned, must also emit UV because some fire-detection hardware use UV sensors to detect a flame. The hottest part of the flame is directly above this blue part at the base of the flame.



The brightest part of the flame is not the hottest. The luminous zone on a candle is where the free carbon burns and releases light - visible light. The fuel of the candle are hydrocarbons. That's a hydrogen and carbon combo. Both are reacting with the oxygen in the air. Hydrogen expands from a solid state into a gas and reacts with oxygen to create water vapour. But what of the carbon? What process does it undergo as it leaves the candle wax, up the wick, and into the flames? Faraday has something interesting to say about carbon vapours while he was burning a piece of charcoal:

You may say that the charcoal is actually dissolving in the air round about; and if that were perfectly pure charcoal, which we can easily prepare, there would be no residue whatever. When we have a perfectly cleansed and purified piece of carbon, there is no ash left. The carbon burns as a solid dense body, that heat alone can not change as to its solidity, and yet it passes away into vapor that never condenses into solid or liquid under ordinary circumstances; and what is more curious still is the fact that the oxygen does not change in its bulk by the solution of the carbon in it. Just as the bulk is at first, so it is at last, only it has become carbonic acid.



Faraday's appears to be saying that the carbon vapourizes. A vapour is often thought of as being a gaseous state which condenses, for example, steam condenses into water. He's also pointing out that the carbon which fully burns does not condense. The "vaporized" carbon maybe thought of as more acting like a gas.

If the flame from the candle touches the glass it can leave a stain of black soot. Soot is unburned carbon fuel. Soot indicates incomplete combustion and the formation of carbon monoxide, a poisonous gas. Complete combustion of the carbon produces practically no soot or carbon monoxide, and is recognised by a blue flame. Where there is soot, there is usually carbon monoxide. One might be persuaded to say that soot is evidence perhaps of where carbon monoxide condenses on a surface. One then might be tempted to conclude that carbon monoxide acts as a vapour, while carbon dioxide acts as a gas.

The bright yellow luminous zone is where the carbon particles become incandescent and the flame yields light. Because we produce the soot from the flame, we could summise that the carbon is not fully vaporised until it reaches the tip of the flame. And it's here we fall into a bit of an argument about which part of the flame is hottest. While some claim the blue part of the flame is hottest, we are also told that the tip of the flame is where you find the most heat. This is because the flame's heat is supposedly delivered toward the tip.

Only thing is - energy belongs to the aether field. Energy is not so much transmitted, but rather accessed. This means energy is not delivered to the tip of the flame. Energy from the aether is being induced by the flame, and for whatever reason, the most heat is induced at the tip of the flame. One might be tempted to describe this heat at the tip of the flame as a "dry" heat, whereas the blue part of the flame might be described as a "wet" heat - as derived from steam.

Can it be said then, that the vaporization of carbon transforms the high energy ultraviolet light into what we see as visible light? The candle flame appears to express quite a number of wavelengths from the electromagnetic spectrum. Starting with the invisible UV at the base of the wick, then moving on to the flame and its yellow, orange and red hues from the visible spectrum, and then to the outer-core of the flame where we have the longer infrared wavelengths.

While writing this blog I have been heavily influenced by proposals made by 19th Century natural philosophers (though I believe humans have known of its existence for a much longer time) - regarding a medium through which EM waves propagate - the "luminiferous aether". Atomic vortices induce the aether to flow through them. EMR is emitted by these vortices as a vibrational wave in the aether.

We are seeing a number of EM waves in the simple flame of a candle. In past posts I have wondered if different molecules have different sized atoms which generate different wavelengths in the aether. It's interesting that we can isolate the handful of gases involved in combustion by peering in the glass of this simple experiment. It's a window to what might be happening in the atmosphere around us.

So far we've looked at only one-fifth of the volume in the glass - what about the other four-fifths? Well, that is nitrogen. We are told that the air around us is made of something like 79% nitrogen. We say there is this much nitrogen in the air basically because we find this much inside the glass AFTER the combustion. But really, was it there BEFORE the combustion?

Some have carried out the experiment using more than one candle. They have found that the more candles you use, then the greater is the volume of water that is pulled into the glass. More than one-fifth is sucked-in. If oxygen in the air was really being burnt then this volume should remain the same - regardless of the number of candles. With more candles you're going to get more heat. Does this mean you get more steam? I think this also helps allay my fears about the amount of water vapour in the air. It means there is not simply one-fifth water vapour in the air, and the amount is still open to interpretation.



Many thanks:


http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/getting-water-from-a-candle/
http://amasci.com/~billb/cgi-bin/miscon/guest04.html
http://www1.umn.edu/ships/updates/after-o2.htm
http://wapedia.mobi/en/Hydrogen
http://www.windows.ucar.edu/tour/link=/glossary/mass.html
http://www.odec.ca/projects/2005/mcma5s0/public_html/projectinfo.html
http://www.physorg.com/news160834772.html
http://icue.nbcunifiles.com/icue/files/icue/site/pdf/39172.pdf
http://www.daviddarling.info/encyclopedia/A/air.html
http://www.3rd1000.com/history/gases.htm
http://chimianet.zefat.ac.il/download/Candle_water_3_sources.do
http://www.av8n.com/physics/vapor.htm
http://www.bashaar.org.il/files/2971.doc
http://www.brazenhussies.net/badgrrlzguide/playingwithfire.html
http://www.explainthatstuff.com/candles.html
http://www.acroname.com/robotics/parts/R67-UVTRON.html
http://www.jstor.org/pss/113624
http://www.sensorland.com/HowPage081.html
http://www.sfdm.scad.edu/faculty/mkesson/vsfx319/wip/best_spring2003/ca301.2/scott_dean/fire/flame.html
http://www.straightdope.com/columns/read/2159/what-is-the-hottest-part-of-a-flame
http://www.investigativeengineering.com/j/index.php/component/content/article/59-phantom-soot
http://www.pdphoto.org/PictureDetail.php?pg=8381

No comments: