# Voltage. What is it really?

This is an analogy I use. Suppose I ask you to carry ten rocks. That tells you how many. Then I tell you that you need to carry them to the top of a mountain. That tells you how much work you must do per rock. Similarly, current is how much charge is being moved per unit of time, and voltage is the work done per unit of charge.

I think the box being pushed analogy makes the most sense. I passed through school and then college without ever realizing how cool this analogy was. Drakkith gave a great thing to remember about voltage!!

sophiecentaur
Gold Member
2020 Award
Why don't you share what you feel sufficient answer? In your first post you state that a voltage is a J/C, which is true, but doesn't really provide insight as to what a volt is in physical terms. After all, a Joule and a Coulomb are just units of length mass time and charge.

Granted I cant answer my own question with great accuracy as I am not an electrical engineer or a physicist who's studied electricity. So how would you describe a volt in terms of physical phenomena?
The word "insight" is a bit like 'motherhood' and no one likes to question it but what are we actually after?
My "sufficient answer" to the whole problem is to use the Definition (V=J/C). This is not a cop out; it Works when you need to predict what will happen in a given situation.

I am just acknowledging that the feeling that people 'need' before they allow themselves to 'understand' things is very little more than Familiarity. Use something enough times and you treat it as second nature. A new piece of what we call understanding is no more than using a new combination of familiar ideas in a way that satisfies us that we "now understand it". We have managed to pigeonhole it amongst the things we feel we are familiar with. (If you are really after improving your understanding, you use these pigeonholes as temporary storage, only - a Scientist is always emptying holes and replacing their contents with an improved version.)
Humans have spent hundreds of years in developing a mathematical system to describe / analyse / predict natural phenomena so why not be prepared to use it? The mathematical descriptions used in Physics are every bit as 'real' as the dodgy analogies that people seem to hang all their hopes on. In my view, it is pointless and fruitless to ask for a 'physically meaningful' explanation for anything but the most concrete phenomena (and even then, the explanation is just not that simple).

I have frequently made the point that many of the posts on these forums (some of mine included, of course) merely serve to confuse the uninitiated. The 'worst' ones are of the rambling, speculative kind which use none of the accepted ideas or the mathematical approach. Unless someone challenges them, they appear just as attractive as the more accepted views and can seriously damage someone's potential learning process.