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Why does current flow the opposite way from the electrons?

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Re: Why does current flow the opposite way from the electrons?

#21
post #7

> that makes electrons negative, and apparently nobody knows why When there is a symmetry, there are choices, all the time in math, and sometime in physics too. Also I don't like calling electrons negative, they are not. Maybe you can say that their charge is -1, when you model charge with the additive structure of real numbers / integers, and you choose the protons charge to correspond to 1. Modeling charge with the…

> So you shouldn't say "electron is negative". That's weird, confusing, misleading, and trolling.

Huh? By the convention you describe (and we all share), electrons have negative charge, since -1 is negative. When speaking in the shared and understood context of charge, you shorten that to saying electrons are negative.

Nothing weird, confusing, or misleading, and certainly not trolling. I'm baffled where you get that from.

Re: Why does current flow the opposite way from the electrons?

#22
post #9

Could be worse. They could have chosen any term implying opposite. We could have had left and right handed charges. Although I suppose we essentially did that when naming the quarks.

The worst part is that up and down are not really opposites. Down is up on the other side of the world.

Up and down are opposites on the other side of the world too...

Re: Why does current flow the opposite way from the electrons?

#23
post #7

> that makes electrons negative, and apparently nobody knows why When there is a symmetry, there are choices, all the time in math, and sometime in physics too. Also I don't like calling electrons negative, they are not. Maybe you can say that their charge is -1, when you model charge with the additive structure of real numbers / integers, and you choose the protons charge to correspond to 1. Modeling charge with the…

> So you shouldn't say "electron is negative". That's weird, confusing, misleading, and trolling. Huh? By the convention you describe (and we all share), electrons have negative charge, since -1 is negative. When speaking in the shared and understood context of charge, you shorten that to saying electrons are negative. Nothing weird, confusing, or misleading, and certainly not trolling. I'm baffled where you get that…

He comes from an accounting background where commonly-understood terms mean the opposite of what everyone commonly understands them to mean.

Re: Why does current flow the opposite way from the electrons?

#24

A big part of this is we measure what's important to us. As an electrician, what's important is which wire is full of angry pixies. They're technical direction of travel is far less important to my job (and my safety). When doing electronics, the direction of travel becomes quite important. So there's a different point of view.

Anytime electrochemistry is involved it's important. But regular electronics not very much. I think positive and negative mostly trips up people trying to use what they think is happening to explain theory. When it's not that useful most of the time.

What I could never keep straight is anode and cathode.

Re: Why does current flow the opposite way from the electrons?

#25
Others have answered correctly (it was an arbitrary choice), but fwiw I always found it helpful to think of current as the direction of the “holes” where electrons can be.

Like bubbles rising in water, the holes “travel” opposite the potential that’s pulling the surrounding electrons the other way.

Re: Why does current flow the opposite way from the electrons?

#26

A big part of this is we measure what's important to us. As an electrician, what's important is which wire is full of angry pixies. They're technical direction of travel is far less important to my job (and my safety). When doing electronics, the direction of travel becomes quite important. So there's a different point of view.

Actually both wires are full of angry pixies, it's just that you have angry pixies in your body that match the ones in one of the wires, so you don't notice when you touch one, and strongly notice when you touch the other.

On top of that if we did not ground one side of the electrical network, you could touch either wire and feel nothing. That's called an isolated ground, and is not commonly used except in hospitals and some other specialty settings.

(If you wonder, we ground one side because if two different people both happened to touch a wire, current would flow between them using the each.)

Re: Why does current flow the opposite way from the electrons?

#28

Because he didn't know anything about electrons, and the experiment he did involving rubbing amber and glass rods on fur and silk cloth only showed that something was transferred between the two materials, and that when the material containing the substance was brought near to the other material containing the other substance, the property conferred by the substances appeared to negate. If you read Teaching Introduct…

It really seems like had a rationale:

"We suppose as aforesaid, That Electrical Fire is a common Element, of which every one of the three Persons abovementioned has his equal Share before any Operation is begun with the Tube. A who stands on Wax, and rubs the Tube, collects the Electrical Fire from himself into the Glass; and his Communication with the common Stock being cut off by the Wax, his Body is not again immediately supply’d. B, who stands upon Wax likewise, passing his Knuckle along near the Tube, receives the Fire which was collected by the Glass from A; and his Communication with the common Stock being likewise cutt off, he retains the additional Quantity received. to C, standing on the Floor, both appear to be electrised; for he having only the middle Quantity of Electrical Fire receives a Spark on approaching B, who has an over-quantity, but gives one to A, who has an under-quantity. If A and B touch each other, the Spark between them is stronger, because the Difference between them is greater. After such Touch, there is no Spark between either of them and C; because the Electrical Fire in all is reduced to the original Equality. If they touch while Electrising, the Equality is never destroyed, the Fire only circulating. Hence have arisen some new Terms among us. We say B (and other Bodies alike circumstanced) are electrised positively; A negatively: Or rather B is electrised plus and A minus. And we daily in our Experiments electrise Bodies plus or minus as we think proper. These Terms we may use till your Philosophers give us better. To electrise plus or minus, no more needs to be known than this; that the Parts of the Tube or Sphere, that are rub’d, do, in the Instant of the Friction, attract the Electrical Fire, and therefore take it from the Thing rubbing: the same Parts immediately, as the Friction upon them ceases, are disposed to give the Fire they have received, to any Body that has less. Thus you may circulate it, as Mr. Watson has shewn; You may also accumulate or subtract it upon, or from any Body, as you connect it with the Rubber or with the Receiver; the Communication with the common Stock being cut off."

from Benjamin Franklin's letter to Peter Collison, May 25, 1747.

Re: Why does current flow the opposite way from the electrons?

#29
post #24

A big part of this is we measure what's important to us. As an electrician, what's important is which wire is full of angry pixies. They're technical direction of travel is far less important to my job (and my safety). When doing electronics, the direction of travel becomes quite important. So there's a different point of view.

Anytime electrochemistry is involved it's important. But regular electronics not very much. I think positive and negative mostly trips up people trying to use what they think is happening to explain theory. When it's not that useful most of the time. What I could never keep straight is anode and cathode.

CAThodes are PAWsitve

Re: Why does current flow the opposite way from the electrons?

#30

Charge carriers aren't always electrons anyway, so you're restricting yourself by thinking of current as electrons moving. Even in the usual case where electrons are the charge carrier, it is only the small net movement of zillions of electrons back and forth which produces a current. So in any case current is a macrostate and electron movement is a microstate, and sign convention won't change that.

Exactly this!

Even the use of 'flow' is misleading. It's barely trickling through the wire...

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