[Amps] "Conventional" current flow

[Vic Rosenthal]

I don't think what he wrote is either incomprehensible or nonsense. I don't pretend to understand quantum mechanics intuitively (maybe humans, whose ability to understand things developed from the necessity of survival in an environment composed of 'things' that are not very small or very big, just can't do that), but people a lot smarter than me have shown that the math works in a practical way to explain things that otherwise would look like magic.

Vic 4X6GP

> On 9 Dec 2016, at 03:35, Bill Turner <dezrat at outlook.com> wrote:
> 
> Jim's post, reprinted in full below, is incomprehensible nonsense.
> Everyone but Jim knows what "current" is: The liquid-like movement of
> particles such as water molecules, air molecules or electrons. 
> For the life of me I do not understand why some people want to make
> things more complex and obscure than they are. Science has always been
> the search for truth except, apparently, when it comes to electricity.
> Ben Franklin made a mistake and we are still paying for it. 
> 
> Time to wise up, folks!
> 
> 73, Bill W6WRT
> 
> 
> 
> 
>> On Wed, 16 Nov 2016 22:16:50 -0700, Jim wrote:
>> 
>> Hi Mike,
>> 
>> Let me give you the simple, direct answer to your question, and then I will give you the more complicated answer that's closer to being correct. In a vacuum tube, the only things that move between the cathode and the anode are electrons, and these move only in one direction, which is toward the anode. There's nothing else moving inside the tube. Note I used the word "move," rather than "flow," because if we have only, say, one electron or a small number of them, then it doesn't make sense to talk about a flow. A single electron is just a moving charge, it's not a flow of anything. A "flow" always represents the aggregate motion of a large number of things. 
>> 
>> 
>> 
>> Now, what about electric current? Unlike a moving charge, current is always represented as a flow of something. Current flows, it doesn't make sense to speak of current moving. Now, here's the important point. Electric current is an abstract concept. It's not a real substance. You can take an electron and weigh it on a scale (in principle!). You can't weigh current, because current is an idea, not a material thing. Using the language of physics, one would say that current represents the impact of moving charges, but is not the charges themselves. So, in a vacuum tube, electrons move from cathode to anode. The current flow, which is in the reverse direction, isn't a real substance. It's just a useful mathematical way of representing the aggregate effect of the moving electrons. The reason current is so useful is because it allows us to ignore the sign of the charges whose impacts we're describing. It doesn't matter whether the charges are negative, like electrons, or positive
> ,
>> like holes, or a mix of the two. Once you've characterized the impact of the charges as a flow of current, you've learned most everything useful about them. 
>> 
>> 
>> 
>> Here's another example. We know that a variable capacitor passes an alternating RF current. But we also know that no charge actually travels between the capacitor plates. So the current flows between the plates, even though no real particle is moving between them. The abstract idea of RF current flowing through the capacitor is just a useful mathematical way of describing the alternate charging and discharging of the capacitor plates.
>> 
>> 
>> 
>> The universe is an extremely subtle place, and our intuition about it is frequently wrong. When an apple falls from a tree, we say that the gravitational force is pulling it down. But in fact gravity isn't really a force. Einstein showed it is just a distortion of space caused by the mass of the earth. Another example: We learn in high school that a hydrogen atom is a negative electron bound to a positive proton, because unlike charges attract each other. But that's not really true. What really happens is that photons pop into existence and are exchanged between the electron and proton and then disappear. (In physics, these are known as the quanta of the electromagnetic field.) And if that isn't strange enough for you, these photons spend part of their short life changing momentarily into electrons and positrons. These are called "virtual" charges because they're so short-lived, and what's especially interesting is that the mass of these virtual charges is greater than the m
> a
>> ss of the photons that created them, thus momentarily violating the conservation of energy. And that's just for starters. Probe more deeply, and things get really, really odd. A vacuum is not an empty space where nothing happens. Particles can pop into existence out of empty space, and then after a short time pop out of existence. (In physics this effect is called the fluctuation of the vacuum state.)
>> 
>> 
>> 
>> So the bottom line is that we shouldn't be troubled by abstract ideas like electric current. Most everything we know about the world is an abstraction of some sort. Instead, we should be grateful that the universe, despite its enormous complexity and subtlety, allows us to simplify its rules into stripped down descriptions that our small brains can understand and that let us do useful things, like build vacuum tubes. 
>> 
>> 73,
>> 
>> Jim W8ZR
>>