No Stupid Questions
No such thing. Ask away!
!nostupidquestions is a community dedicated to being helpful and answering each others' questions on various topics.
The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:
Rules (interactive)
Rule 1- All posts must be legitimate questions. All post titles must include a question.
All posts must be legitimate questions, and all post titles must include a question. Questions that are joke or trolling questions, memes, song lyrics as title, etc. are not allowed here. See Rule 6 for all exceptions.
Rule 2- Your question subject cannot be illegal or NSFW material.
Your question subject cannot be illegal or NSFW material. You will be warned first, banned second.
Rule 3- Do not seek mental, medical and professional help here.
Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.
Rule 4- No self promotion or upvote-farming of any kind.
That's it.
Rule 5- No baiting or sealioning or promoting an agenda.
Questions which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.
Rule 6- Regarding META posts and joke questions.
Provided it is about the community itself, you may post non-question posts using the [META] tag on your post title.
On fridays, you are allowed to post meme and troll questions, on the condition that it's in text format only, and conforms with our other rules. These posts MUST include the [NSQ Friday] tag in their title.
If you post a serious question on friday and are looking only for legitimate answers, then please include the [Serious] tag on your post. Irrelevant replies will then be removed by moderators.
Rule 7- You can't intentionally annoy, mock, or harass other members.
If you intentionally annoy, mock, harass, or discriminate against any individual member, you will be removed.
Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.
Rule 8- All comments should try to stay relevant to their parent content.
Rule 9- Reposts from other platforms are not allowed.
Let everyone have their own content.
Rule 10- Majority of bots aren't allowed to participate here.
Credits
Our breathtaking icon was bestowed upon us by @Cevilia!
The greatest banner of all time: by @TheOneWithTheHair!
view the rest of the comments
There may be several answers to this. This is my somewhat simplified take.
One is, it's a (series of) physical action (heating, gasification, pyrolysis -- break-up of molecules of the fuel) and chemical reactions (oxidation). Oxidation means in general (in a commonly accepted model) that an atom shares away its outer electrons, which makes it acquire a lower energetic state. Oxygen is one element that is eager to attract such electrons for the same reason.
Whenever such a reaction happens, the superflous energy is released as a quant of electromagnetic radiation (a wave/particle) which we call a photon (it's therefore called an exothermic reaction). Photons can appear to us as visible light (that is wavelenghts in the visible spectrum). The wavelength of a photon inverse-correlates with the energy of the photon (blue > red).
Getting the reaction going however, requires the molecules of the fuel to get excited with energy in the first place, which is the required activation energy. This can be done by heating the atoms of the fuel. And as the oxidation also emits heat energy (far infrared), and in fact more than what is required for the whole phsyical-chemical process to happen, it can sustain itself (given the right conditions, see the second answer). This self-sustaining gassification, pyrolysis and oxidation we call a flame.
Flame colours are composed of the glow of gases at different temperatures ("red" is colder than "white") and the colour corresponding to the wavelength of the photons emitted in the oxidation reaction (simplified). In a typical candle flame, we see mainly hydrogen burning at the lower end (where the flame is blue but the gas is still reatively cold). Carbon takes a bit more activation energy (burns less easily), so it will start to oxidise farther up the flame where the gas is hotter. Carbon will make an orange flame at these temperatures. Other elements burn in all kinds of colours. A burning copper wire will make a flame glow green. Print colours on paper can contain metals which burn in different colours.
The other answer is how I explain how to make a "smokeless" campfire.
A fire needs three things: fuel (something to burn, wood), oxigen (air), and heat. Smoke is just the gases coming out of the wood condensating because they are either not hot enough for activation of the final combustion, or there is too little air getting into the hot zone of the fuel. Anything that is smoke could be a flame when the smoking part is put into a hotter place. Black smoke usually means that there is too little heat for the carbon to get fully oxidised. Cold fuel and having to evaporate water in the wood generally takes away heat from the flames.
TL;DR: A flame is a self-sustaining combustion process in a mixture of gases that needs to be hot and be steadily fed with fuel and oxygen. The gas is so hot that it glows.