When you see a object Which takes fire without an apparently visible flame, the first reaction is of amazement: “Is it magic? It is self -mutation“.” In reality, the phenomenon has a very specific scientific explanation, which involves the properties of fuel and the nature of the flame it produces. Let’s see how it works.
The most common episode in which you can come across an “invisible flame” takes place using a normal Hanging gel for the hands. Many of these products contain ethyl alcohol (ethanol) In concentrations that can exceed 60%. The label of some gels reports, for example, the 62% of ethyl alcohol en masse.
When the gel is approached to a source of heat or trigger (lighter, match or another flame already on), the alcohol reacts with the oxygen of the air producing carbon dioxide And water vaporfreeing energy in the form of heat And light. However, if we observe the flame to a certain angle or in intense light conditions, this can be almost invisible.
But why is the flame shortly visible? The main reason lies in the chemical of ethyl alcohol. When it burns, the ethanol generates a relatively flame cold (compared, for example, to that produced by more complex hydrocarbons such as butane or petrol) and of bluish color or almost transparent. Consequently, in conditions of strong environmental light or with a certain background, the flame can only be seen with difficulty.
Also, as alcohol is consumed, the flame decreases in intensityaccentuating the “disappearance” effect. Hence the illusion that the object is born Going over it spontaneouslywhen there is an effective combustion reaction, only less evident.
Consequently, if we approach the invisible flame a piece of paper, the latter will begin to burn. If you are not aware of the presence of the flame, a person might think it is self -mutation (a process in which a substance takes fire alone, without any external trigger), but in our case it is simply an “optical effect” of the flame of the ethyl alcohol.
