[dukhsan] Hellfire

[dukhsan]

It is possible under certain conditions to create a flame in real life that appears black to observers. How can this happen?

This is unabashedly a scientific puzzle, as I've done in the past, but it is too cool to not share.
Searching the web for this concept specifically could have a high chance of finding the answer early, just to throw this out there.
That said, I imagine there are ways to carefully dig up information. I can offer hints if needed.

[Balin]

Is it relevant what material is burned to create the flame? Is an accelerant used? If so, relevant which?
Would all observers of this flame see it as black?

[dukhsan]

Is it relevant what material is burned to create the flame? Is an accelerant used? If so, relevant which? Several combinations of materials could be used to get this effect, as far as I can see. Besides the fuel itself, there is nothing I would describe as an accelerant.

Would all observers of this flame see it as black? Yes, if they had normal vision - the same as basically any other flame.

[GalFisk]

I've seen this on video, and it was awesome. I want to try it myself some time.
Interesting subject, good luck with the puzzle.

[Balin]

Is the flame burned in front of a certain background? Is it burned above ground? Does the flame last a long time? Or is it a short sudden flame?

[dukhsan]

I've seen this on video, and it was awesome. I want to try it myself some time. It does look like a great project if I happened upon the right circumstances to try it.

Is the flame burned in front of a certain background? It may depend on your definition of background. This is worth exploring. Is it burned above ground? Yes, and maybe also irrelevant.

Does the flame last a long time? Or is it a short sudden flame? Could choose either, as far as I can tell.

[Balin]

Is the flame burned outdoors? Indoors? During the day? At night? In certain weather conditions?

[dukhsan]

Is the flame burned outdoors? Indoors? Indoors.
During the day? At night? In certain weather conditions? All irrelevant with the correct setup.

[Balin]

Is the flame enclosed? Open?

[dukhsan]

Is the flame enclosed? Open? An open flame.

[Earnest]

Chemical elements relevant? If so, in the air? Put in the flame? In the fuel used to ignite the flame? Relevant how the flame is "produced"? Does it work for instance with a kitchen stove?

Is the black appearence of the flame due to a chemical modification of the flame? An optic illusion? A distrtion of our perceptio of the flame, which is instead unchanged in its components?

[dukhsan]

Chemical elements relevant? Yes. If so, in the air? No, nothing special in the air near the fire; all fires do require air to function, though.
Put in the flame? Yes. In the fuel used to ignite the flame? It could either be there at the beginning of the flame or added later. Relevant how the flame is "produced"? Yes, but it is mostly a common flame; anyone could make it, but not everyone has the tools to make it appear black. Does it work for instance with a kitchen stove? I cannot think of an ordinary gas or electric stove that would work with this.

Is the black appearence of the flame due to a chemical modification of the flame? An optic illusion? Both. Good questions. A distrtion of our perceptio of the flame, which is instead unchanged in its components? There is something going on besides the flame itself, but the flame is modified.

[Earnest]

Is the chemical element a fuel? Is it black? Does it have another color that when burned becomes black? Is it in liquid form? In gas form? In solid form? Is the black chemical element part of an object? (E.g. an object with a black colorant?)
Can the object be burned? Is it usual to burn it?
Is the object easy to handle? Is it considered "dangerous"? Is it a common substance in its original form? (E.g. colorant is considered common because present in almost any object, however it is uncommon in its original form which, I think, is handled just in laboratories?

[dukhsan]

Is the chemical element a fuel? The element that can be used in this trick to get the black color is not itself a fuel, at least in the form we are using. Is it black? Does it have another color that when burned becomes black? The element is not directly black, nor are any of its compounds that we care about. Is it in liquid form? In gas form? In solid form? If you were doing this yourself, you would start with a solid substance containing this element, but that changes.

Is the black chemical element part of an object? (E.g. an object with a black colorant?) Can the object be burned? Is it usual to burn it? The element that gets us the black color is part of a compound that cannot itself be burned.

Is the object easy to handle? Is it considered "dangerous"? It's common, and it's fine to handle. Is it a common substance in its original form? (E.g. colorant is considered common because present in almost any object, however it is uncommon in its original form which, I think, is handled just in laboratories? You see this substance very often.

[Earnest]

cannot itself be burned because it can explode? It is dangerous? It is not inflammable? It is poisonous once burned? Is it necessary to melt the original substance? Is it something related to food? To technology? Are batteries relevant? A toy?

Do we just need to figure out the solid object and the substance? Does the object need to be opened to get access to the chemical element? To change its molecukar composition? Through heat? Through cold? Is the chemical element per se in liquid form? Solid?

[dukhsan]

cannot itself be burned because it can explode? It is dangerous? It is not inflammable? This one; in the compound we care about it doesn't burn. For the rest of the forum, remember that inflammable does mean that it can burn. It is poisonous once burned?

Is it necessary to melt the original substance? Not melt, but we don't use it as a pure substance either. Is it something related to food? To technology? Are batteries relevant? A toy? The substance can probably be found in all of these, or at least used in their manufacture.

Do we just need to figure out the solid object and the substance? This is part of it; we then need to figure out the optical/light component to making the black fire happen.

Does the object need to be opened to get access to the chemical element? To change its molecukar composition? Through heat? Through cold? Is the chemical element per se in liquid form? Solid? The compound that contains the element is solid and we use it in an easily available way. It does not change into another compound, but heat is relevant because we are discussing fire.

[Earnest]

Ok so let's say I have a phone. Let's say an iPhone. Since the compound is also in it, can I find it in the external part of the phone? Can I see it at a first glance? Do I need to open the phone? Search inside the batteries of the phone? In the internal engines? Is the paint of the phone relevant? Is the phone the object in which the compound is mostly used?
Is the compound black? Is it artificially produced by man? Is it mainly found in an object that we handle every day?

Is the substance physically put in the flames? Does the black color appear once the substance is burned? Does the fire need to be lighted up before the substance come into contact with the fire or can the substance be put together with the wood and other fuel and the fire lighted up afterward? If the former, does the fire need to be lighted up with a particular fuel? Was this known and possible also in middle age? To be sure...are we talking about a fire that can be lighted up or a fire like for instance the one produced by the sun and present there?



P.s. sorry but I had my last experience with chemistry 7 years ago.

[dukhsan]

Ok so let's say I have a phone. Let's say an iPhone. Since the compound is also in it, can I find it in the external part of the phone? Some plastics might be made with that compound, but by that point it's an entirely different compound if so; let's say irrelevant for including it in a phone case.

Can I see it at a first glance? Do I need to open the phone? Search inside the batteries of the phone? In the internal engines? Is the paint of the phone relevant? Is the phone the object in which the compound is mostly used? I cannot imagine that most of it worldwide is used in electronics, including phones. I'm not aware of it specifically being in batteries or the circuitry, but I might just not know offhand. Let's try to find this compound in another place besides electronics to determine what it is - it should go faster this way.
Is the compound black? Is it artificially produced by man? Is it mainly found in an object that we handle every day? It is not black, it is found naturally, and we do handle things that contain it daily.

Is the substance physically put in the flames? Yes. Does the black color appear once the substance is burned? The fuel with the substance inside it does create the black flame when we also add the the optical-illusion part of the experiment. Does the fire need to be lighted up before the substance come into contact with the fire or can the substance be put together with the wood and other fuel and the fire lighted up afterward? Either; the fire can start off with the substance, or it can be added later. Wood is not the fuel used here, also. If the former, does the fire need to be lighted up with a particular fuel? It uses a certain liquid fuel.

Was this known and possible also in middle age? No, and not possible then. To be sure...are we talking about a fire that can be lighted up or a fire like for instance the one produced by the sun and present there? The sun "burns" with nuclear fusion, so it is the common type of fire we want.

P.s. sorry but I had my last experience with chemistry 7 years ago. No apologies needed at all - thanks very much for playing along! I try to give longer explanations on science puzzles because anything less is honestly a bit punishing for folks who haven't done this or it's been a while. The goal is to share something cool about science in puzzle format in a way that people can hopefully remember better when solving, or follow along if they read it later in the archives.

[Earnest]

he goal is to share something cool about science in puzzle format in a way that people can hopefully remember better when solving, or follow along if they read it later in the archives --> that's brilliant!

It is not black, it is found naturally, and we do handle things that contain it daily --> ok so...food related? Drink related? Clothing related? Is it in objects of our house? In objects of the same type? Is film relevant? Plastic?
Found naturally = in mines? in woods? in contains? in fields? in water? in wells? Are there jobs devoted to the extraction of the substance? Under ground? in minerals? is geology relevant? Is it found in nature as a compound? Is it the result of a natural process (for instance erosion by water; is something that after been burned forms the compound)? Is it produced by animals?

liquid fuel = oil? alcohol?

Optical component = a gas? An illusion depending on the point of view according to which the fire is seen? Is the optical/light component introduced after the substance? Is a picture taken (e.g. the flashing of the camera gives the optical illusion)? Are light waves relevant?

[dukhsan]

It is not black, it is found naturally, and we do handle things that contain it daily --> ok so...food related? Yes. Drink related? Sometimes. Clothing related? Not specifically or relevantly. Is it in objects of our house? Yes. In objects of the same type? Is film relevant? Plastic? Plastic is irrelevant here.

Found naturally = in mines? in woods? in contains? in fields? in water? in wells? Mines and water; also other places but mostly these. Are there jobs devoted to the extraction of the substance? Yes. Under ground? in minerals? is geology relevant? Sometimes underground minerals, but not always. Is it found in nature as a compound? Yes. Is it the result of a natural process (for instance erosion by water; is something that after been burned forms the compound)? Yes. Is it produced by animals? No, not in the form that we use at least.

liquid fuel = oil? alcohol? Alcohol, methyl alcohol is best but this may also work with ethyl alcohol.

Optical component = a gas? No. An illusion depending on the point of view according to which the fire is seen? No. Is the optical/light component introduced after the substance? Either after or before the fire is lit; it does not matter. Is a picture taken (e.g. the flashing of the camera gives the optical illusion)? No, but this black flame does show up on camera. Are light waves relevant? Yes. Explore this one.

[Earnest]

so...methyl alcohol and light waves and something food related found in mines and water right?
carbon dioxide relevant? light waves = the ones produced by the fire burning with alcohol? Or maybe by an artificial light? By something else? I mean...I do not know if it is correct but actually what I have in mind is something like the "reproduction on a smaller scale" of an "atmosphere-like environment". As far as I know up in the atmosphere there is an high concentration of carbon dioxide which absorbs light waves produced by the sun, represented in our case by the fire. Hence, by introducing an higher proportion of carbon dioxide with respect to a certain parameter (maybe the light waves?) many of the light spectrum should be absorbed producing the black illusion? Is more a question than a guess actually xD

[dukhsan]

so...methyl alcohol and light waves and something food related found in mines and water right? Yes. A compound commonly found in food/water is dissolved in methyl alcohol and the alcohol is burned. We are also looking at a different source of light not produced by the fire itself.

carbon dioxide relevant? No. light waves = the ones produced by the fire burning with alcohol? No. Or maybe by an artificial light? Yes, explore this one! By something else?

I mean...I do not know if it is correct but actually what I have in mind is something like the "reproduction on a smaller scale" of an "atmosphere-like environment". As far as I know up in the atmosphere there is an high concentration of carbon dioxide which absorbs light waves produced by the sun, represented in our case by the fire. Hence, by introducing an higher proportion of carbon dioxide with respect to a certain parameter (maybe the light waves?) many of the light spectrum should be absorbed producing the black illusion? Is more a question than a guess actually xD It's a great guess, and a lot of it is really on the right track! We do not need to reproduce the conditions of the upper atmosphere, but you are totally correct in that black is what we see when something absorbs basically all of the light that hits it - getting very close.

[wolfier]

Yes. A compound commonly found in food/water is dissolved in methyl alcohol and the alcohol is burned. We are also looking at a different source of light not produced by the fire itself

Is it a compound that we either know what it is or not? Just want to see whether there is a better way of solving it than invoking every element on the periodic table one after another...

[dukhsan]

Is it a compound that we either know what it is or not? Just want to see whether there is a better way of solving it than invoking every element on the periodic table one after another... It is common table salt, sodium chloride. Invoking the list is honestly fine for these types of puzzles.

[dukhsan]

This is close enough that I'm going to call it here - there have been some impressive questions asked.

****SPOILER****

The element sodium, in its metallic and ionic forms, glows a characteristic yellow when its atoms are 'excited' by adding energy. Specifically, they release the energy that they absorbed in the form of yellow light.

In particular, a sodium-vapor lamp uses sodium in an inert atmosphere inside a bulb to emit light that is almost entirely two shades of very, very similar yellow. Objects illuminated by this type of lamp appear in a sort of 'grayscale', except it's black and yellow instead of black and white. The objects appear either some intensity of yellow if they reflect some or all of the yellow light hitting them, or they are black if they absorb the yellow light - black is the color we see when something reflects very little of the light that hits it.

If we light a flame using methyl alcohol as the fuel, and do this in a room where the only significant light source is a sodium-vapor lamp, the flame appears sufficiently normal at first. However, if we either dissolve sodium chloride - table salt - into the methyl alcohol, or add a bit of salt water to the flame as it burns (water mixes well with methyl alcohol), then the flame suddenly appears black! The sodium ions from the salt absorb the exact yellow light that the sodium atoms in the vapor lamp emits - creating a flame that absorbs so much of the light hitting it that it seems black in this special setting.

This video shows the trick in action: https://www.youtube.com/watch?v=5ZNNDA2WUSU

Hellfire and Dark Inferno are magical attacks used by vampire lord Dracula in the Castlevania series of video games.

Thanks for playing!