I can create a current without using the electromotive force.

Drop a charged object in an gravitational field. The gravitational force is responsible for the movement of charge, no electric force needed.

Bob

You still have a difference in potential, otherwise the object would not move. Maybe one should think in more general terms, not consequently referring to a voltage

 

Because classical electronic circuits are engineering solutions. They make the proper simplifying assumptions of quasi-static conditions because it works if you follow the engineering rules.

OK - now I know what you mean.
But I am sure that the questioner with his problem description follows these engineering rules.

 

This thread reminds me of the parable of the blind men describing an elephant:
https://en.wikipedia.org/wiki/Blind_men_and_an_elephant

Engineers sometimes need to be reminded that voltages and currents are derived abstract concepts, not fundamental physical things. Voltage is a convenient way to describe changes in electric potential (another abstraction), and current is a rate of charge flow. They are high-level simplifications of a single underlying physical process (the behavior of the electromagnetic field). It doesn't make physical sense to describe one as causing the other, they're two different ways of looking at the same physics.

 

This thread reminds me of the parable of the blind men describing an elephant:
https://en.wikipedia.org/wiki/Blind_men_and_an_elephant

Engineers sometimes need to be reminded that voltages and currents are derived abstract concepts, not fundamental physical things. Voltage is a convenient way to describe changes in electric potential (another abstraction), and current is a rate of charge flow. They are high-level simplifications of a single underlying physical process (the behavior of the electromagnetic field). It doesn't make physical sense to describe one as causing the other, they're two different ways of looking at the same physics.

I don't know that I'd go that far (saying that they are two different ways of looking at the same thing). It would be hard to tell someone to describe a charged capacitor from a current standpoint and claim that it contains the same information as looking at it from a voltage standpoint -- the same with trying to do something similar to an electromagnet. Also, the notion of an electromagnetic field is also an abstraction.

 

... Like @bogosort has noted, voltage and current are just components or constituents of what we think of as power, and the integral over time of power, which is energy, sometimes known as work.

 

I don't know that I'd go that far (saying that they are two different ways of looking at the same thing). It would be hard to tell someone to describe a charged capacitor from a current standpoint and claim that it contains the same information as looking at it from a voltage standpoint -- the same with trying to do something similar to an electromagnet. Also, the notion of an electromagnetic field is also an abstraction.

I agree that they do not present the same information, which is by design -- they are simplifying (dimension-reducing) characterizations of the same fundamental physical process. Heat and entropy perform a similar role, and hopefully no one would suggest that heat causes entropy or vice versa.

And yes, the EM field is an abstraction, but it's much closer to the source, so to speak.

 

I don't know that I'd go that far (saying that they are two different ways of looking at the same thing). It would be hard to tell someone to describe a charged capacitor from a current standpoint and claim that it contains the same information as looking at it from a voltage standpoint -- the same with trying to do something similar to an electromagnet. Also, the notion of an electromagnetic field is also an abstraction.

An abstraction yes, but If it carries energy and momentum then it's as real as a rock hitting you in the head.

https://www.feynmanlectures.caltech.edu/I_10.html

One of the propositions of Newton was that interactions at a distance are instantaneous. It turns out that such is not the case; in situations involving electrical forces, for instance, if an electrical charge at one location is suddenly moved, the effects on another charge, at another place, do not appear instantaneously—there is a little delay. In those circumstances, even if the forces are equal the momentum will not check out; there will be a short time during which there will be trouble, because for a while the first charge will feel a certain reaction force, say, and will pick up some momentum, but the second charge has felt nothing and has not yet changed its momentum. It takes time for the influence to cross the intervening distance, which it does at 186,000 miles a second. In that tiny time the momentum of the particles is not conserved. Of course after the second charge has felt the effect of the first one and all is quieted down, the momentum equation will check out all right, but during that small interval momentum is not conserved. We represent this by saying that during this interval there is another kind of momentum besides that of the particle, mv, and that is momentum in the electromagnetic field. If we add the field momentum to the momentum of the particles, then momentum is conserved at any moment all the time. The fact that the electromagnetic field can possess momentum and energy makes that field very real, and so, for better understanding, the original idea that there are just the forces between particles has to be modified to the idea that a particle makes a field, and a field acts on another particle, and the field itself has such familiar properties as energy content and momentum, just as particles can have. To take another example: an electromagnetic field has waves, which we call light; it turns out that light also carries momentum with it, so when light impinges on an object it carries in a certain amount of momentum per second; this is equivalent to a force, because if the illuminated object is picking up a certain amount of momentum per second, its momentum is changing and the situation is exactly the same as if there were a force on it. Light can exert pressure by bombarding an object; this pressure is very small, but with sufficiently delicate apparatus it is measurable.

 

In an interview Richard Feynman trys to explain the role of distance as a kinematic predominant factor in a conductor circuit and in the atmosphere.

With a mathematical proof a corollary must be shown to be true. Both the chicken and the egg are necessary. As the charge approaches conduction the kinetic energy transfers to potential energy. Now it can be expressed mathematically as i=dq / dt it can be stated quantitatively that the number of charges per unit time passing through a boundary equals the current. And this proof gets quite long by when the component associated with magnetic momenta are inserted. This is outside the scope of electronic circuits. When it comes to problem solving with a resistance circuit the process is either series or parallel the units can be applied. The chicken and egg are both there. When it's time to set up the equation it is not a relevant to the procedure. It would be a distraction like trying to contemplate breathing when swinging a golf club. The golfer would improve by developing a well practiced routine.

Because of the conceptual flaws we have been noticing about electrical conduction an effort is made to help visualize the mechanics (of a conducting flow) to improve the understanding about the nature and origin of electricity. Feynman's explanation could be expanded to show a variety of ways the principals apply. In the study of electronics an emphasis on applications in circuits.

 

Is it the potential difference that creates the current or is it the current that creates the potential difference?

Okay you guys , what did you do with @Raúl Figueirinha. He has to pick a winner to be crowned the new naturally occurring phenomenon.

 

Okay you guys , what did you do with @Raúl Figueirinha. He has to pick a winner to be crowned the new naturally occurring phenomenon.

Some questions that seem simple are not.

 

Okay you guys , what did you do with @Raúl Figueirinha. He has to pick a winner to be crowned the new naturally occurring phenomenon.

I got the impression that the answer to the original question depends on whether you are an engineer, theoretical physicist or a philosopher

 

I got the impression that the answer to the original question depends on whether you are an engineer, theoretical physicist or a philosopher

Magnificent! I was on a committee responsible to pick the color of the book used by theoretical physicists we kept it gray

 

I got the impression that the answer to the original question depends on whether you are an engineer, theoretical physicist or a philosopher

The answer of the the physicist and philosopher might be close to this. Voltage vs Current cause and consequence are an illusion.

Everything contains Yin and Yang and nothing is absolute with Yin and Yang

http://www.numericana.com/arms/bohr.htm