Yes, this is correct.

Okay great, so in that reply you linked where you said "while this could be true" regarding interpreting negative current as net flow of negative charge, I am slightly confused. If you include the word net in the sentence as in: A negative current represents a NET flow of negative charge in the direction of you arrow, would the statement always be true? I don't know if that person changed their text or anything and left off the word net originally, which that would make sense why it isn't always true (because maybe sometimes only positive charge moves), but what would be the situation in which this statement is not true if the word net is included?

Also, could we talk about what actual current means. You said if you had a reference arrow pointing to the right and the 'actual current' was -10A than you could say electrons are going to the right, and as always the actual current would be flowing to the left, against electrons (I am paraphrasing because I don't want to bring that thread up if I am not supposed to). So I am confused an actual current of -10A to the right means actual current goes to the left? Is actual current only allowed to be positive or did you mean the actual current of +10A goes to the left? I just don't understand this term. I thought any current, positive or negative, up or down, left or right, were all actual current? I could be wrong though, like I said I haven't dealt with this terminology much in high school.

 

Okay great, so in that reply you linked where you said "while this could be true" regarding interpreting negative current as net flow of negative charge, I am slightly confused. If you include the word net in the sentence as in: A negative current represents a NET flow of negative charge in the direction of you arrow, would the statement always be true? I don't know if that person changed their text or anything and left off the word net originally, which that would make sense why it isn't always true (because maybe sometimes only positive charge moves), but what would be the situation in which this statement is not true if the word net is included?

Also, could we talk about what actual current means. You said if you had a reference arrow pointing to the right and the 'actual current' was -10A than you could say electrons are going to the right, and as always the actual current would be flowing to the left, against electrons (I am paraphrasing because I don't want to bring that thread up if I am not supposed to). So I am confused an actual current of -10A to the right means actual current goes to the left? Is actual current only allowed to be positive or did you mean the actual current of +10A goes to the left? I just don't understand this term. I thought any current, positive or negative, up or down, left or right, were all actual current? I could be wrong though, like I said I haven't dealt with this terminology much in high school.

The word "net" just means the overall result. Imagine a bucket that has some water in it and we define the water flow as positive for water entering the bucket. Now say that we have two pipes connected to the bucket and in one pipe we have 2 gal/min flowing into the bucket and in the other pipe we have 5 gal/min flowing out of the pipe. The current in the first pipe would be +2 gal/min and the current in the other pipe would be -5 gal/min. The net current flowing into the bucket is -3 gal/min.

We could describe this mathematically by saying that the net current flowing into the bucket equals the time rate of change of the volume of water in the bucket.

Now what if the bucket was sealed and made so small that it was really just the junction of the pipes connected to it with the result being that the volume of water in the junction was effectively zero or, more to the point, couldn't change appreciably. Under these circumstances we could modify our mathematical description to something simpler and say that the net current flowing into the junction is zero. Sounds an awful lot like KCL doesn't it? In fact, KCL is not an absolute law, it is a law that applies to the special case where we assume the total charge stored on an electrical junction is fixed (namely zero). The actual law that is a special case of states that the next current flowing into a junction is equal to the time rate of change of electrical charge on that junction.

So "net current" covers the possibility that there are multiple currents flowing in a branch. In circuit analysis this often arises when we are using superposition or mesh currents, for instance. But if can also happen in the physical world, for instance, two ion beams traveling what is effectively the same path.

The term "actual current" is just to make a distinction from "symbolic current". When we draw a current arrow on a diagram and label it Io, then Io is the symbolic current in that branch. The actual current would usually refer to either the numeric value of Io or possibly to the expression for it in terms of other variables.

 

The word "net" just means the overall result. Imagine a bucket that has some water in it and we define the water flow as positive for water entering the bucket. Now say that we have two pipes connected to the bucket and in one pipe we have 2 gal/min flowing into the bucket and in the other pipe we have 5 gal/min flowing out of the pipe. The current in the first pipe would be +2 gal/min and the current in the other pipe would be -5 gal/min. The net current flowing into the bucket is -3 gal/min.

We could describe this mathematically by saying that the net current flowing into the bucket equals the time rate of change of the volume of water in the bucket.

Now what if the bucket was sealed and made so small that it was really just the junction of the pipes connected to it with the result being that the volume of water in the junction was effectively zero or, more to the point, couldn't change appreciably. Under these circumstances we could modify our mathematical description to something simpler and say that the net current flowing into the junction is zero. Sounds an awful lot like KCL doesn't it? In fact, KCL is not an absolute law, it is a law that applies to the special case where we assume the total charge stored on an electrical junction is fixed (namely zero). The actual law that is a special case of states that the next current flowing into a junction is equal to the time rate of change of electrical charge on that junction.

So "net current" covers the possibility that there are multiple currents flowing in a branch. In circuit analysis this often arises when we are using superposition or mesh currents, for instance. But if can also happen in the physical world, for instance, two ion beams traveling what is effectively the same path.

The term "actual current" is just to make a distinction from "symbolic current". When we draw a current arrow on a diagram and label it Io, then Io is the symbolic current in that branch. The actual current would usually refer to either the numeric value of Io or possibly to the expression for it in terms of other variables.

Okay that makes a lot of sense. So since we have two types of charge for electronics, it seems to make things a bit deeper, no? As if we had a type of negative water?

Overall, would it be fine if I said a positive current means that positive charge goes in your reference arrow or negative charge moves the opposite your arrow. Thus, a negative current means that positive charge goes opposite your reference arrow or negative charge moves in the direction of your arrow. So a negative current means a net flow of negative charge or electrons in the direction of your arrow (assuming a circuit with wire not water). Are these statements 100% true?

And with actual current if you had a negative actual current to the right than negative charges (electrons, others) go right, and positive charges go left. If you had a positive actual current right than negative charges (electrons) go left?

Sorry just want to make sure the way my head processes these two new terms correctly, I would rather understand this than NEETS which seems to be mathematically incorrect. Not sure how that would be of benefit to learn that.

 

Yes, that all sounds fine.

 

Yes, that all sounds fine.

Okay so on this site when it says conventional current flows from + of battery to -, we are supposed to imagine some positive value? Meaning we could put conventional current from - to +, but you would have to put a - value? I know you already touched on this being conventional, I am just confused about why the site's article only says conventional current vs. electron flow is up to the direction your arrow is drawn. But based on your info, it seems the arrow can go whatever way you want, in either convention, the sign is what the important part is?

Also, I am still confused on your one response from the thread you linked. I reworded that OP comment as basically saying negative current means you have a net flow of negative charge (electrons) in the direction of your arrow, and you said that this may be true, but you really should be saying negative current means you have a net flow of (positive) charge the other way. Could you give the example of a time when the net flow of negative charge comment would NOT be correct?

I think I am really understanding this so thanks for your answers! This website deserves more popularity from students!

 

I have addressed all of this ad nauseam. I have given numerous explanations and examples. I can't do any better than I have already attempted to do. I see no point in continuing and I am done.

 

I have addressed all of this ad nauseam. I have given numerous explanations and examples. I can't do any better than I have already attempted to do. I see no point in continuing and I am done.

Oh okay, that is fine. I will leave stuff related to the other thread alone. I am going to assume for that one the OP in that section left off the word net or something and therefore the statement negative current means you have negative charge in the direction of your arrow wouldn't always be true, because a negative current could be due to positive charges the opposite way like you stated. The word net must be included or that statement can't always be true, so I am assuming that's why you responded the way you did. I won't bother much about that though.

But if you wouldn't mind could we talk real quick about the article on this site since I don't believe that was covered (correct me if I am wrong there). In the one picture, it just shows an arrow for conventional current going from + to - and then the other arrow labeled electron flow goes from - to +. But based off what you said conventional can go from + to - or - to +, it just needs to have the correct sign. I guess the article is just a little vague in defining what each of those mean? I know you may not be the author of this article, just wondering if you have any perspective of maybe adding more details, or if I am potentially wrong and no details should be added.

 

Oh okay, that is fine. I will leave stuff related to the other thread alone. I am going to assume for that one the OP in that section left off the word net or something and therefore the statement negative current means you have negative charge in the direction of your arrow wouldn't always be true, because a negative current could be due to positive charges the opposite way like you stated. The word net must be included or that statement can't always be true, so I am assuming that's why you responded the way you did. I won't bother much about that though.

But if you wouldn't mind could we talk real quick about the article on this site since I don't believe that was covered (correct me if I am wrong there). In the one picture, it just shows an arrow for conventional current going from + to - and then the other arrow labeled electron flow goes from - to +. But based off what you said conventional can go from + to - or - to +, it just needs to have the correct sign. I guess the article is just a little vague in defining what each of those mean? I know you may not be the author of this article, just wondering if you have any perspective of maybe adding more details, or if I am potentially wrong and no details should be added.

The arrows in the diagrams you are referring to are not reference arrows (of the type that you draw when you are defining the current in a branch). They are intended by the author to illustrate the motion of something in those circuits. In the conventional flow case the arrows illustrate the direction that (positive) charge flows in the circuit. In the other case the arrows illustrate the direction that electrons flow in the circuit. The author makes several of the same mistakes that most authors that talk about electron flow make as a result of confusing the flow of charge with the flow of charge carriers. Further, the author claims that the mathematical analysis of circuits is equally valid using both and I have shown several ways in which this claim is only true -- for the way that nearly all electron-flow acolytes perform it -- if you incorporate magical mystery minus signs.

Regardless of which convention you use and whether you use electron flow properly or improperly, when you define the references for the currents in the circuit you can ALWAYS flip a coin and point the arrow in which ever direction the coin dictates. Always. It is arbitrary. ALL that the direction of the arrow does is tell you how to interpret the numeric value of the current based on its polarity according to the convention you have chosen to use. I showed this very explicitly here:

https://forum.allaboutcircuits.com/threads/conventional-vs-electron-flow.166883/post-1476934

 

The arrows in the diagrams you are referring to are not reference arrows (of the type that you draw when you are defining the current in a branch). They are intended by the author to illustrate the motion of something in those circuits. In the conventional flow case the arrows illustrate the direction that (positive) charge flows in the circuit. In the other case the arrows illustrate the direction that electrons flow in the circuit. The author makes several of the same mistakes that most authors that talk about electron flow make as a result of confusing the flow of charge with the flow of charge carriers. Further, the author claims that the mathematical analysis of circuits is equally valid using both and I have shown several ways in which this claim is only true -- for the way that nearly all electron-flow acolytes perform it -- if you incorporate magical mystery minus signs.

Regardless of which convention you use and whether you use electron flow properly or improperly, when you define the references for the currents in the circuit you can ALWAYS flip a coin and point the arrow in which ever direction the coin dictates. Always. It is arbitrary. ALL that the direction of the arrow does is tell you how to interpret the numeric value of the current based on its polarity according to the convention you have chosen to use. I showed this very explicitly here:

https://forum.allaboutcircuits.com/threads/conventional-vs-electron-flow.166883/post-1476934

Oh okay, I see now, this makes much more sense. The arrow in a circuit diagram will help you find out the actual current, which if it is negative your reference arrow is in the electron direction, if it is positive, it is opposite the electron direction. I just got confused because although electron flow done consistently is conventional current, it seems like you were still referring to it as a separate entity in the other thread. And in the differences in those equations in that post, it would only be in how passive sign convention and Ohm's law is operated under either convention?

So why are people so angry with Ben Franklin about this? In what way would we be better off giving current a positive value in the direction of negatively charged electrons? He put negative current in the direction of negative charge flow, that makes perfect sense! I guess people would prefer electrons to hold a positive charge and that was what is "wrong"

 

So why are people so angry with Ben Franklin about this? In what way would we be better off giving current a positive value in the direction of negatively charged electrons? He put negative current in the direction of negative charge flow, that makes perfect sense! I guess people would prefer electrons to hold a positive charge and that was what is "wrong"

As with everything else. already addressed:
https://forum.allaboutcircuits.com/threads/conventional-vs-electron-flow.166883/post-1477094

 

Nobody is angry with Ben Franklin. Frankly, he did nothing wrong.
As I mentioned in the other thread, it really does not matter if you label the charge with a + or - sign. Label it # and * for all I care. It does not change the way we view and analyze electrical circuits. Get over it.

 

As with everything else. already addressed:
https://forum.allaboutcircuits.com/threads/conventional-vs-electron-flow.166883/post-1477094

Okay, so essentially Franklin didn't necessarily define positive current, he defined what positive charge was? And from this since he defined current as the flow of charge, he assigned a positive current value to the direction of charges that were stationary (to be consistent with the definition of positive charge)? Basically, when some people say he did it 'wrong' they don't mean he should have put a positive value in the direction of negatives, but rather it would have been 'better' to make the positive charges the ones that were moving the majority of the time?

 

Nobody is angry with Ben Franklin. Frankly, he did nothing wrong.
As I mentioned in the other thread, it really does not matter if you label the charge with a + or - sign. Label it # and * for all I care. It does not change the way we view and analyze electrical circuits. Get over it.

While researching this, I have seen outside sources that have criticized Franklin. I have not seen that here though so fair enough. And agreed it didn't have to be + or - but even if they were # and *, you would still have currents with + or - values? It would just read something like positive current is in the direction of # charge and negative current is in the direction of * charge?

 

Okay, so essentially Franklin didn't necessarily define positive current, he defined what positive charge was? And from this since he defined current as the flow of charge, he assigned a positive current value to the direction of charges that were stationary (to be consistent with the definition of positive charge)? Basically, when some people say he did it 'wrong' they don't mean he should have put a positive value in the direction of negatives, but rather it would have been 'better' to make the positive charges the ones that were moving the majority of the time?

He indirectly defined what positive charge was.

Before Franklin the dominant theory involved there being two type of electric fluids. Franklin proposed a one-fluid theory and showed that it was perfectly capable of explaining everything that the two-fluid theory did. It turns out that this was somewhat coincidental because, in all of the various studies and experiments up to that time, all of the electrical phenomena could be explained by the transfer of a single type charge. In general this is not the case, but it was the case for everything that he and others had data for at the time. In a real sense, the two-fluid model was actually closer to reality (but not in the manner in which it was used to explain the data -- the one-fluid theory was better for that).

Franklin assigned positive to any substance that had more fluid that it would naturally have ('naturally' meaning that under normal conditions all materials have just the right amount of fluid to make them electrically neutral). He also proposed the notion of the conservation of fluid, something which we now embody in the notion of the conservation of total charge, something that still holds even at the subatomic level.

The only "mistake" he made was in assuming that, when rubbed, fluid was transferred from silk to glass and not the other way around. Thus glass was considered to have excess fluid and, hence, a positive charge. I've never seen anything that describes why he made this assumption or to what degree he was aware that the other assumption would have been equally valid based on the data he was trying to explain. But whether he was or not, it underscores the fact that, in nearly all situations, the transfer of one kind of charge in one direction is indistinguishable from transferring the opposite kind of charge in the other direction.

As for what the websites and books and other things have to say about it, almost all of them are based on repeating the gist of the claim that the authors heard as kids in school and have simply been unquestioned. It is essentially a tale of folklore that has been boiled down to an overly simplified rendition that is easy for school kids to remember on the upcoming exam and, like any such thing, is almost devoid of actual technical accuracy.

 

He indirectly defined what positive charge was.

Before Franklin the dominant theory involved there being two type of electric fluids. Franklin proposed a one-fluid theory and showed that it was perfectly capable of explaining everything that the two-fluid theory did. It turns out that this was somewhat coincidental because, in all of the various studies and experiments up to that time, all of the electrical phenomena could be explained by the transfer of a single type charge. In general this is not the case, but it was the case for everything that he and others had data for at the time. In a real sense, the two-fluid model was actually closer to reality (but not in the manner in which it was used to explain the data -- the one-fluid theory was better for that).

Franklin assigned positive to any substance that had more fluid that it would naturally have ('naturally' meaning that under normal conditions all materials have just the right amount of fluid to make them electrically neutral). He also proposed the notion of the conservation of fluid, something which we now embody in the notion of the conservation of total charge, something that still holds even at the subatomic level.

The only "mistake" he made was in assuming that, when rubbed, fluid was transferred from silk to glass and not the other way around. Thus glass was considered to have excess fluid and, hence, a positive charge. I've never seen anything that describes why he made this assumption or to what degree he was aware that the other assumption would have been equally valid based on the data he was trying to explain. But whether he was or not, it underscores the fact that, in nearly all situations, the transfer of one kind of charge in one direction is indistinguishable from transferring the opposite kind of charge in the other direction.

As for what the websites and books and other things have to say about it, almost all of them are based on repeating the gist of the claim that the authors heard as kids in school and have simply been unquestioned. It is essentially a tale of folklore that has been boiled down to an overly simplified rendition that is easy for school kids to remember on the upcoming exam and, like any such thing, is almost devoid of actual technical accuracy.

This is very interesting. So essentially he imagine that there was only one type of charge coming in the form of fluid. Therefore, if in Franklin's time you solved for a negative value for current, he wouldn't say it was wrong, but he also wouldn't imagine anything flowing in that direction at all. If you told him it was even possible for that to happen, he would disagree? Presently we know that a negative value indicates negative charge movement in that reference direction, at least in wires or other circuits conducting negative ions. While we still may not think of it that way, if you asked any person it seems that they would agree, because they know there are two types of charge? So like you said he defined what positive charge was, and thus from that it made sense to put positive current in the direction positive charge would move. So the only thing "wrong" is the fact that it would be slightly more convenient for an electron to be defined as positive charge, because then positive current would flow the same direction as electrons, and it would hold up in any other mathematical sense. How have you been able to find such a deep understanding in this despite the steady perpetuation about false, vague, or blatantly incorrect summaries of this topic?

Bottom line is it seems like the order of conventions went something like this: Franklin unknowingly labels charge as a single positive fluid going from his defined + to - of a voltage source. He imagined this fluid as physically moving from + to -. Then, the electron is discovered, and rather than change voltage definitions and charge definitions, we just decided to make the electron negative, in order to maintain mathematical equivalence of our system. If the electron was defined as negative, we knew it would carry negative current, and thus be equivalent to Franklin's positive fluid going the other way, so the convention still worked? Because even if the electron was never discovered, we could still write our currents as negative values form - to + and be mathematically consistent with Franklin's hypothesis.

 

This is very interesting. So essentially he imagine that there was only one type of charge coming in the form of fluid. Therefore, if in Franklin's time you solved for a negative value for current, he wouldn't say it was wrong, but he also wouldn't imagine anything flowing in that direction at all. If you told him it was even possible for that to happen, he would disagree? Presently we know that a negative value indicates negative charge movement in that reference direction, at least in wires or other circuits conducting negative ions. While we still may not think of it that way, if you asked any person it seems that they would agree, because they know there are two types of charge? So like you said he defined what positive charge was, and thus from that it made sense to put positive current in the direction positive charge would move. So the only thing "wrong" is the fact that it would be slightly more convenient for an electron to be defined as positive charge, because then positive current would flow the same direction as electrons, and it would hold up in any other mathematical sense. How have you been able to find such a deep understanding in this despite the steady perpetuation about false, vague, or blatantly incorrect summaries of this topic?

Bottom line is it seems like the order of conventions went something like this: Franklin unknowingly labels charge as a single positive fluid going from his defined + to - of a voltage source. He imagined this fluid as physically moving from + to -. Then, the electron is discovered, and rather than change voltage definitions and charge definitions, we just decided to make the electron negative, in order to maintain mathematical equivalence of our system. If the electron was defined as negative, we knew it would carry negative current, and thus be equivalent to Franklin's positive fluid going the other way, so the convention still worked? Because even if the electron was never discovered, we could still write our currents as negative values form - to + and be mathematically consistent with Franklin's hypothesis.

In Franklin's time no one solved for current because the notion of quantifying electrical current and electrical voltage hadn't yet occurred and wouldn't for several more decades. In those days work was done with electrostatic devices and observations were purely qualitative in nature and the theories were attempting to explain two aspects: the charging and discharging of objects, and the attraction/repulsion of charged objects. Franklin's work that eventually resulting in the assignment of the polarity of the charge on an electron happened around 1750. Nearly all work done up to this point used static electricity produced by rubbing different materials together. A reasonably efficient means of doing this was invented around 1650 and is the basis behind the Van der Graaf generator. Just a few years earlier (~1745) the Leyden jar, which is essentially a glass capacitor, was invented. Franklin (and many others) had been experimenting with them and he coined the term "electrical battery" for a collection of them in series. As most people of the time, he was trying to understand and explain electricity in terms of concepts already familiar to them and describing things in terms of the properties of fluids seemed quite reasonable. The older and competing two-fluid theory was described mostly in terms of the two types of fluids ("vitreous" and "resinous") being produced or destroyed independently of each other by some process. Franklin's one-fluid theory explained things in term of a single type of fluid being moved from one object to another. The Leyden jar was the culmination of attempts to capture some of fluid (regardless of whether it was one fluid or two different fluids) in a jar. But after showing that the same phenomena could be obtained without any jar and just using flat plates of glass. Franklin himself explained this by describing one side of the plate becoming positively charged and the other plate being negatively charged. In this model, the fluid was positively charged and flowed from what would become the negative plate to the positive plate. That the fluid was "positive" is simply a natural way of assigning polarities. But his earlier work had already deemed that this "positively charged" fluid flowed from silk to glass when, in reality, the "fluid" (i.e., electrons) flow from the glass to the silk.

The invention of the chemical battery would not occur of another fifty years (1799 by Alessandro Volta) and the discovery of the electron wouldn't occur for a century after that (1897 by J. J. Thompson). Despite that, once we had a means of working with sustainable and relatively constant voltages delivered by chemical batteries, a lot of things were able to happen. Georg Ohm developed what would become Ohm's Law in 1826, The period from about 1760 to 1860 (mostly after about 1820) saw all of the key elements that James Clerk Maxwell brought together in Maxwell's Equations in 1862. Keep in mind that Maxwell's equations themselves predate the discovery of the electron by well over a quarter of a century.

So Franklin was one of the leading pioneers in the efforts that led to where we are today. It's a remarkable testament to his genius of how close he was able to describe things given the context of the body of knowledge of his time -- and it's not surprising that his theories didn't explain everything.

 

In Franklin's time no one solved for current because the notion of quantifying electrical current and electrical voltage hadn't yet occurred and wouldn't for several more decades. In those days work was done with electrostatic devices and observations were purely qualitative in nature and the theories were attempting to explain two aspects: the charging and discharging of objects, and the attraction/repulsion of charged objects. Franklin's work that eventually resulting in the assignment of the polarity of the charge on an electron happened around 1750. Nearly all work done up to this point used static electricity produced by rubbing different materials together. A reasonably efficient means of doing this was invented around 1650 and is the basis behind the Van der Graaf generator. Just a few years earlier (~1745) the Leyden jar, which is essentially a glass capacitor, was invented. Franklin (and many others) had been experimenting with them and he coined the term "electrical battery" for a collection of them in series. As most people of the time, he was trying to understand and explain electricity in terms of concepts already familiar to them and describing things in terms of the properties of fluids seemed quite reasonable. The older and competing two-fluid theory was described mostly in terms of the two types of fluids ("vitreous" and "resinous") being produced or destroyed independently of each other by some process. Franklin's one-fluid theory explained things in term of a single type of fluid being moved from one object to another. The Leyden jar was the culmination of attempts to capture some of fluid (regardless of whether it was one fluid or two different fluids) in a jar. But after showing that the same phenomena could be obtained without any jar and just using flat plates of glass. Franklin himself explained this by describing one side of the plate becoming positively charged and the other plate being negatively charged. In this model, the fluid was positively charged and flowed from what would become the negative plate to the positive plate. That the fluid was "positive" is simply a natural way of assigning polarities. But his earlier work had already deemed that this "positively charged" fluid flowed from silk to glass when, in reality, the "fluid" (i.e., electrons) flow from the glass to the silk.

The invention of the chemical battery would not occur of another fifty years (1799 by Alessandro Volta) and the discovery of the electron wouldn't occur for a century after that (1897 by J. J. Thompson). Despite that, once we had a means of working with sustainable and relatively constant voltages delivered by chemical batteries, a lot of things were able to happen. Georg Ohm developed what would become Ohm's Law in 1826, The period from about 1760 to 1860 (mostly after about 1820) saw all of the key elements that James Clerk Maxwell brought together in Maxwell's Equations in 1862. Keep in mind that Maxwell's equations themselves predate the discovery of the electron by well over a quarter of a century.

So Franklin was one of the leading pioneers in the efforts that led to where we are today. It's a remarkable testament to his genius of how close he was able to describe things given the context of the body of knowledge of his time -- and it's not surprising that his theories didn't explain everything.

Okay, why did the positive fluid go from the negative plate to positive plate but now we say negative current goes from negative to positive? Is this referring to like inside a battery positive current would be flowing from negative to positive or is this still in an external circuit?

That is quite astonishing that Maxwell equations were created so early on. This level of knowledge is what I desire. What resources did you use to get to this understanding? Books like Griffith's electrodynamics? Other books? It seems the basic circuit books (including this one) are just going to give you basic statements like "conventional current always moves opposite electrons", without going into the full details that yes positive conventional current moves opposite electrons and negative conventional current goes opposite positive conventional current, and since they both move opposite positive, they go the same way. It seems like we are scaring students away from thinking about electrons and - signs when they are just fine. You want to represent some electron movement from a to b? Do so with an arrow pointing from a to b with a -value and everything is consistent. And this is just a beginning topic so does this vagueness continue from here. Is it only in graduate school that you could get a detailed look at the physics and underlying emag theory? I don't know how comfortable you are with sharing a bit of your background, but this vagueness seems to be a problem in a field that should maintain mathematical rigor.

 

Okay, why did the positive fluid go from the negative plate to positive plate but now we say negative current goes from negative to positive? Is this referring to like inside a battery positive current would be flowing from negative to positive or is this still in an external circuit?

The thing to keep in mind is that it is referring to charging a capacitor (or recharging a battery).

So imagine that you have a bunch of very small white balls and a bunch of very small black balls in two buckets. They are small enough that each bucket looks like it contains a bunch of grey balls.

Now you connect a device between the two buckets and turn it on and you notice that the bucket on the left begins to look blacker and the bucket on the right tends to look whiter. You might explain this by saying that the device is turning white balls black in the left bucket and turning black balls white in the right bucket. With this theory there is no need to consider the possibility that and balls are being transferred from one bucket to the other -- you could theorize that it is moving black balls in one direction and white balls in the other, but there is no need to do so. This is essentially the two-fluid model.

But another way to explain it is to consider that there is only one kind of fluid and that the device moves some of this fluid from one bucket to the other. But does it move white balls to the left or black balls to the right? But to ask the question this way you have to be thinking in terms of two different colored balls -- instead, you are thinking in terms of a single color of ball and some mechanism whereby if there are more than the natural amount of balls the bucket it looks one color but if less than the natural amount it looks the other color. Now let's say that in the left bucket the balls are embedded in a solid but in the right bucket they are in a gel. It probably makes sense to surmise that balls are moving from the gel (right bucket) to the solid (left bucket) rather than the other way around. Since the solid bucket is getting blacker you conclude that the balls that make up the fluid are black and therefore anything that looks blacker than grey has a more black balls than normal and is thus positively charged, but anything that is whiter than grey has fewer black balls than normal and is thus negatively charged. Here, the notion of positive and negative has nothing to do with the polarity of the charge, but rather whether the total number of balls (total amount of fluid) is more or less than the equilibrium point (zero charge).

So you publish your work and others reproduce it and they try it with a lot of other materials and they adopt your notion that the fluid consists of black balls and that an excess of black balls constitutes a positive charge. But a century or so later it is discovered that there really are black balls and white balls and that in all of these experiments it was actually white balls going the other way (but it is also being discovered that you can create devices and situations in which it really is black balls moving in the original direction).

Do we need to change anything? No. Remember, a bucket was defined as having a positive charge if it has more black balls than white balls. All that has been altered is that now we know that this condition arose not because we added black balls to the bucket, but because we removed white balls from it. There's no compelling reason to change the definition of what we consider to be a positive charge and a negative charge.

That is quite astonishing that Maxwell equations were created so early on. This level of knowledge is what I desire. What resources did you use to get to this understanding? Books like Griffith's electrodynamics? Other books? It seems the basic circuit books (including this one) are just going to give you basic statements like "conventional current always moves opposite electrons", without going into the full details that yes positive conventional current moves opposite electrons and negative conventional current goes opposite positive conventional current, and since they both move opposite positive, they go the same way. It seems like we are scaring students away from thinking about electrons and - signs when they are just fine. You want to represent some electron movement from a to b? Do so with an arrow pointing from a to b with a -value and everything is consistent. And this is just a beginning topic so does this vagueness continue from here. Is it only in graduate school that you could get a detailed look at the physics and underlying emag theory? I don't know how comfortable you are with sharing a bit of your background, but this vagueness seems to be a problem in a field that should maintain mathematical rigor.

This information is all out there on the web and is not too hard to find. But you do have to look for it and be willing to take quite a bit of it with a grain of salt. So finding "good" information is quite a bit harder.

My undergraduate background was in an engineering physics program and, in general, physics courses go much more in depth into the history of discovery and not just what was discovered. So it is very common to see significant portions of a text devoted to the history of the material being presented. There are probably a few reasons for this. Probably the biggest is that most physics programs are primarily interested in developing scientists and not engineers -- it's a different mindset. A scientist tends to be focused on the how and why things work and is much more likely to be interested in discovering new knowledge in this regard, so physics programs tend to have a significant element aimed at understanding how new knowledge is discovered and an integral part of this is becoming familiar with how new knowledge has been discovered historically. Engineers, on the other hand, tend to be focused on how to apply existing knowledge to solve practical problems and so engineering programs are much more knowledge-centric and focused on developing good problem solving skills to apply that knowledge. Certainly there's cross over and the very existence of engineering physics programs represents a deliberate effort to try to blend the best aspects of both (while recognizing that some of the depth of each is sacrificed in the process).

 

The thing to keep in mind is that it is referring to charging a capacitor (or recharging a battery).

So imagine that you have a bunch of very small white balls and a bunch of very small black balls in two buckets. They are small enough that each bucket looks like it contains a bunch of grey balls.

Now you connect a device between the two buckets and turn it on and you notice that the bucket on the left begins to look blacker and the bucket on the right tends to look whiter. You might explain this by saying that the device is turning white balls black in the left bucket and turning black balls white in the right bucket. With this theory there is no need to consider the possibility that and balls are being transferred from one bucket to the other -- you could theorize that it is moving black balls in one direction and white balls in the other, but there is no need to do so. This is essentially the two-fluid model.

But another way to explain it is to consider that there is only one kind of fluid and that the device moves some of this fluid from one bucket to the other. But does it move white balls to the left or black balls to the right? But to ask the question this way you have to be thinking in terms of two different colored balls -- instead, you are thinking in terms of a single color of ball and some mechanism whereby if there are more than the natural amount of balls the bucket it looks one color but if less than the natural amount it looks the other color. Now let's say that in the left bucket the balls are embedded in a solid but in the right bucket they are in a gel. It probably makes sense to surmise that balls are moving from the gel (right bucket) to the solid (left bucket) rather than the other way around. Since the solid bucket is getting blacker you conclude that the balls that make up the fluid are black and therefore anything that looks blacker than grey has a more black balls than normal and is thus positively charged, but anything that is whiter than grey has fewer black balls than normal and is thus negatively charged. Here, the notion of positive and negative has nothing to do with the polarity of the charge, but rather whether the total number of balls (total amount of fluid) is more or less than the equilibrium point (zero charge).

So you publish your work and others reproduce it and they try it with a lot of other materials and they adopt your notion that the fluid consists of black balls and that an excess of black balls constitutes a positive charge. But a century or so later it is discovered that there really are black balls and white balls and that in all of these experiments it was actually white balls going the other way (but it is also being discovered that you can create devices and situations in which it really is black balls moving in the original direction).

Do we need to change anything? No. Remember, a bucket was defined as having a positive charge if it has more black balls than white balls. All that has been altered is that now we know that this condition arose not because we added black balls to the bucket, but because we removed white balls from it. There's no compelling reason to change the definition of what we consider to be a positive charge and a negative charge.



This information is all out there on the web and is not too hard to find. But you do have to look for it and be willing to take quite a bit of it with a grain of salt. So finding "good" information is quite a bit harder.

My undergraduate background was in an engineering physics program and, in general, physics courses go much more in depth into the history of discovery and not just what was discovered. So it is very common to see significant portions of a text devoted to the history of the material being presented. There are probably a few reasons for this. Probably the biggest is that most physics programs are primarily interested in developing scientists and not engineers -- it's a different mindset. A scientist tends to be focused on the how and why things work and is much more likely to be interested in discovering new knowledge in this regard, so physics programs tend to have a significant element aimed at understanding how new knowledge is discovered and an integral part of this is becoming familiar with how new knowledge has been discovered historically. Engineers, on the other hand, tend to be focused on how to apply existing knowledge to solve practical problems and so engineering programs are much more knowledge-centric and focused on developing good problem solving skills to apply that knowledge. Certainly there's cross over and the very existence of engineering physics programs represents a deliberate effort to try to blend the best aspects of both (while recognizing that some of the depth of each is sacrificed in the process).

Do you have recommendations of books that really explain the fundamentals in a deep and complete way? I have looked here, Wikipedia, circuits tutorials websites, and others that just give the same basic statement "current moves opposite electrons, by convention". This is stated repeatedly without saying whether this is true for positive or negative values of current, how it came about, etc. I realize most people don't care, but what if you are a person who cares, where do you go? I feel like books are written by people who are more rigorous in their definitions, but even some of those are vague? I saw the Nilsson and Riedel text you linked in the other thread after reading through it more, and that seemed pretty good. That explanation was something like you assign a reference arrow, value is positive if positive charge moves in the direction of the arrow or negative moves opposite. Value is negative is negative charge moves in the direction of the arrow or positive moves opposite. I mean why is this not the standard explanation? Instead we tell students current moves opposite electrons and then right after show them a positive value one way is equivalent to a negative value the other way, wait what? Two arrows going separate ways are both opposite electrons? Well, no we mean positive current goes opposite electrons. Oh okay, well why not be specific? Maybe I am just annoyingly detailed because of only doing math and science classes my whole life, but I want to find other texts that provide similar levels of detail. Maybe my reasoning above is still not correct, but it seems to agree with what you have explained, so maybe we should just be more detailed in our initial explanations, or maybe it's just stupid and I am being to critical.

I have even seen a book that says if you get a negative current that it indicates the actual current goes opposite the reference direction. This is extremely misleading because negative current and positive current are both actually current. One is not more current than the other, at least I haven't ever seen that written.

FYI thanks for the explanation above, it now seems clear that Franklin wasn't really using current the way we do. What he really "got wrong" is that electrons might have been more convenient to be positive, at least in some other opinions.

 

The thing to keep in mind is that it is referring to charging a capacitor (or recharging a battery).

So imagine that you have a bunch of very small white balls and a bunch of very small black balls in two buckets. They are small enough that each bucket looks like it contains a bunch of grey balls.

Now you connect a device between the two buckets and turn it on and you notice that the bucket on the left begins to look blacker and the bucket on the right tends to look whiter. You might explain this by saying that the device is turning white balls black in the left bucket and turning black balls white in the right bucket. With this theory there is no need to consider the possibility that and balls are being transferred from one bucket to the other -- you could theorize that it is moving black balls in one direction and white balls in the other, but there is no need to do so. This is essentially the two-fluid model.

But another way to explain it is to consider that there is only one kind of fluid and that the device moves some of this fluid from one bucket to the other. But does it move white balls to the left or black balls to the right? But to ask the question this way you have to be thinking in terms of two different colored balls -- instead, you are thinking in terms of a single color of ball and some mechanism whereby if there are more than the natural amount of balls the bucket it looks one color but if less than the natural amount it looks the other color. Now let's say that in the left bucket the balls are embedded in a solid but in the right bucket they are in a gel. It probably makes sense to surmise that balls are moving from the gel (right bucket) to the solid (left bucket) rather than the other way around. Since the solid bucket is getting blacker you conclude that the balls that make up the fluid are black and therefore anything that looks blacker than grey has a more black balls than normal and is thus positively charged, but anything that is whiter than grey has fewer black balls than normal and is thus negatively charged. Here, the notion of positive and negative has nothing to do with the polarity of the charge, but rather whether the total number of balls (total amount of fluid) is more or less than the equilibrium point (zero charge).

So you publish your work and others reproduce it and they try it with a lot of other materials and they adopt your notion that the fluid consists of black balls and that an excess of black balls constitutes a positive charge. But a century or so later it is discovered that there really are black balls and white balls and that in all of these experiments it was actually white balls going the other way (but it is also being discovered that you can create devices and situations in which it really is black balls moving in the original direction).

Do we need to change anything? No. Remember, a bucket was defined as having a positive charge if it has more black balls than white balls. All that has been altered is that now we know that this condition arose not because we added black balls to the bucket, but because we removed white balls from it. There's no compelling reason to change the definition of what we consider to be a positive charge and a negative charge.



This information is all out there on the web and is not too hard to find. But you do have to look for it and be willing to take quite a bit of it with a grain of salt. So finding "good" information is quite a bit harder.

My undergraduate background was in an engineering physics program and, in general, physics courses go much more in depth into the history of discovery and not just what was discovered. So it is very common to see significant portions of a text devoted to the history of the material being presented. There are probably a few reasons for this. Probably the biggest is that most physics programs are primarily interested in developing scientists and not engineers -- it's a different mindset. A scientist tends to be focused on the how and why things work and is much more likely to be interested in discovering new knowledge in this regard, so physics programs tend to have a significant element aimed at understanding how new knowledge is discovered and an integral part of this is becoming familiar with how new knowledge has been discovered historically. Engineers, on the other hand, tend to be focused on how to apply existing knowledge to solve practical problems and so engineering programs are much more knowledge-centric and focused on developing good problem solving skills to apply that knowledge. Certainly there's cross over and the very existence of engineering physics programs represents a deliberate effort to try to blend the best aspects of both (while recognizing that some of the depth of each is sacrificed in the process).

My other comment was a little long winded, if you don't want to read any of that I understand haha. The big thing I was trying to say was a lot of books just seem flat out wrong making statements like "a negative current means the real or actual current is going the other way" so I would prefer to get any book recommendations that go into the details and do so correctly, if you have any recommendations. Like I said Nilsson seemed pretty good.