@foolishmuse s to another baryon). All the mesons quickly decay to a cobination of photons, (anti)electrons and (anti)neutrinos, nothing remains from them. Very large mesons can also decay to baryons but it is very rare. In practice, if you shot protons and neutrons, you will get the protons and neutrons unchanged and a fireball of mesons, quickly decaying to a gamma flash.

@foolishmuse Afaik that is more complex. Yes proton has 3 quarks in it, all the 3 has infinite many similar reactions with the 2 other gluons. Thus all of these happen, with different "weighting". Yet bigger "gluon" exists for a moment, so will it be lesser weight. Now the proton will be the weighted average of this infinite possible interactions. If you calculate these all, the result will be that while you want to remove a quark from the proton, you will need so many energy for that a pair production will happen, resulting that you get a meson and the proton remains as it is (possible change

I think this answer is essentially very similar to mine, except this is more simple. Only being short might be also an advantage, particularly for lesser learned readers. I can not agree the generally negative attitude of the downers, I think they generally misunderstood the answer.

Genial insight, sad that you are not here :-(

@BobD I am not sure if it wpuld be a correct answer. The blue spark with the yellow fire should result green color, but I have never seen that. A green thing would suggest imho some ionized or burning copper compound, most likely. This is why I am not sure.

This is caused by that the air is hot. These effects exist simultanously and it can result various colors.

Blue color is coming from ionized air. I.e. electrons are teared down from the oxygen and nitrogen atoms (molecules), as they find their way back, they radiate out a photon. This photon energy is very characteristic to the actual reaction, and it might be anything from low infrared to soft roentgen. This time it happens to be blue. That is not temperature radiation, i.e. it is not from glowing, due to temperature. But the yellow color were very likely from temperature. Things glowing at about 1000C have yellow-orange color (roughly like the color of the active cigarette endings).

Oversimplified summary: changing electric field generates a magnetic field. Changing magnetic field generates an electric field. Light is a wavefront of electric and magnetic fields generating each other. Light is also described as a bunch of photons. A photon is a small, rotating "needle" in this wavefront.

@RogerV. link, probably researcher level. | I think that shows clearly that it is needed here.

@RogerV. I have not ever heard about it in a electronical engineer bsc course. Ohm formula was simply declared, we have also got a heuristical explanation about the kinetical interaction of the electron gas with the atoms (ions). At that time the focus was on the analysis of the linear circuits. We can talk about it, what is "well known". I have heard about it here and now first time. Note, searching for "how to derive ohms law from maxwells equations" the results: 1) this post here 2) roughly bsc-level, mostly unrelated text at the lous de broglie foundation 3) a reddit link 4) researchgate

@RogerV. I agree that Ohm created a purely empirical law and this "retconned" derivation has more a curiosity value.

@RogerV. The most upvoted answer has a derivation of Ohm's law. If I understand it well, it simplifies matter to a network of charged, randomly moving particles and their response for a small, external electric field. I find the answer awesome. Before this answer, I could not even imagine that such a derivation might exist. I had a heuristic concept of a flow of electrons hitting the ions and losing kinetical energy.

@RogerV. I have learned a lot of similar textbooks and Ohm's Law was simply declared. It was not physics but electroengineer course. I think specialists physics books might have this. Probably you have. Very likely, not even most experts of the field could give the most upvoted answer.

Result would be that not all possible rotations in a (-,-,-,+,+,+) spacetime would be allowed, only 3 independent (-,+) and the purely spatial rotations. I am nearly sure, it would keep causality.

An idea: currently, our "velocity" on the temporal axis is determined by our 3-velocity and by the fact that our 4-velocity is fixed $c$. We can not alter directly our t-velocity, it is determined by our spatial velocity. What if things are the same, but more complex on multiple temporal dimensions. Obviously, some relation should exist which determines the "temporal velocities". I am not sure, how would it be possible with 2 temporal dimensions, but it would be easy for 3 temporal dimensions, by pairing the temporal and spatial axes.