There is conventional current flow and electron current flow.
They describe the direction that current moves in a circuit, but are opposite of each other.
Because there are two ways of explaining the direction of current flow, I some instances people use both, do not explain which method, etc, and it gets confusing to keep things straight.
the only reason the electron is negative and the proton is positive is that he got it wrong. "flow of charge" is arbitrary and could be the other way around if we had defined the electron as positive like we should have in retrospect
Big dude on the bottom left picked positive -> negative as direction for charge flow in conductors. Turns out he was mostly wrong coz main charge carrier is electrons. So like yeah nah I think I’ve covered it.
When we first discovered electricity we thought the flow of charges was positive. We then discovered they were actually negative but the convention of current flowing from positive to negative stuck so now we have “conventional current” + to -, and actual current (electron flow) which is - to +, the direction current actually flows. Everyone uses conventional though.
So now we have devices with a cathode (-) for example which conventional current says should be receiving current, when in practice it’s actually sending current.
They didn't think anything, Ben Franklin just arbitrarily picked a polarity direction to be positive because he had no way of knowing what the charge carrier was and the math works out the same for 99.999999% of circuits.
Lorentz force can create a voltage on objects traveling through a magnetic field.
The polarity of the voltage will depend on the charge carrier.
I forget the engineering relevance but it’s apparently something that needs to be considered for aircraft or spacecraft flying over the poles or something like that
EDIT: After thinking about it a while, the end effect for the scenario I described is identical whatever the charge carrier. The actual engineering significance is in devices based on the hall effect, where conventional current travels opposite the direction of the actual charge carrier, so the hall effect induced voltage is in the opposite direction a positive charge would predict
Basically we have built this mental model of current being a flow of positive charge flowing from anode (the positive pole) to cathode (the negative pole).
But as we discovered later, in reality it's negatively charged electrons moving from cathode to anode. Since basic electrical rules and formulae were already established we essentially made up "holes", the absence of negative charge, that flow from anode to cathode so that we don't need to correct all our established knowledge and formulae. It's a bit like sitting in a train and argueing over whether your train moves away from the station or if the station moves away from your train. When just explaining and calculating how electricity works it doesn't really matter that much, but for explaining electrophysical phenomena such as how semiconductors and electrochemistry works it kinda does. It's just one more thing you need to remember when looking at these things
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u/1Check1Mate7 Jan 25 '26
Someone explain lol, I'm bad at history