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Sick of ridiculous KVL infighting

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PlainName:

--- Quote from: Simon on January 14, 2022, 12:30:14 pm ---My memory is that Lewin demonstrated that the law did not hold, but gave no further explanation as though he had proved someone wrong. As a lesson that is a failure.

--- End quote ---

Disclaimer: I know nothing about all this (in fact, this thread is the first time I've tripped over it). If you're teaching someone, surely you don't show them the answers to every problem straight off? You pose a problem and they figure out how to solve it. Teaching is simply giving them the means to find a solution, not giving them the answers. So posing an issue (something doesn't work as expected) it seems to me to be fine to then let them figure out wtf is going on. Later, either no-one figures it and you have to explain, or it is figured and you smooth over the rough edges.

Berni:
This stuff is still going?

The reason why people can't come to an agreement with each other is that both sides are correct from a given point of view. The physicists and electronics engineers look at it in different ways, that both work within the given context. One of the explanations deals with electric/magnetic fields in 3D space, the other deals with voltages and currents inside a circuit diagram. Both come to the same result.

Just stick to the explanation that works best for you stop trying to convince others that your way is the 'only and only correct way'. Both explanations are idealized cases that ignore certain other natural effects(and rightly so, since why include stuff that have negligible effect on the result).

It's the same as arguing about light being treated as particles as being wrong. Mr. Maxwell there clearly shows how light is also just a electromagnetic wave. Yet you wouldn't use waves to calculate at what angle a laser beam will bounce off a mirror. Yet then again Maxwells equations don't describe the packet nature of light, so are they also wrong? No point in being overly pedantic for no reason. As long as an equation works within the context it was made, just make sure to use it within the correct context.

PlainName:

--- Quote --- No point in being overly pedantic for no reason
--- End quote ---

But... it's the internet.

Berni:

--- Quote from: dunkemhigh on January 14, 2022, 01:32:50 pm ---
--- Quote --- No point in being overly pedantic for no reason
--- End quote ---

But... it's the internet.

--- End quote ---

Indeed...

instrumental:

--- Quote from: Berni on January 14, 2022, 01:30:49 pm ---This stuff is still going?

The reason why people can't come to an agreement with each other is that both sides are correct from a given point of view. The physicists and electronics engineers look at it in different ways, that both work within the given context. One of the explanations deals with electric/magnetic fields in 3D space, the other deals with voltages and currents inside a circuit diagram. Both come to the same result.

Just stick to the explanation that works best for you stop trying to convince others that your way is the 'only and only correct way'. Both explanations are idealized cases that ignore certain other natural effects(and rightly so, since why include stuff that have negligible effect on the result).

It's the same as arguing about light being treated as particles as being wrong. Mr. Maxwell there clearly shows how light is also just a electromagnetic wave. Yet you wouldn't use waves to calculate at what angle a laser beam will bounce off a mirror. Yet then again Maxwells equations don't describe the packet nature of light, so are they also wrong? No point in being overly pedantic for no reason. As long as an equation works within the context it was made, just make sure to use it within the correct context.

--- End quote ---

I'm not sure I agree with this. Both sides are correct up to a point; then, one answer strongly dominates the other. It's a matter of knowing when certain approximations can be made and when those approximations no longer hold.

Newtonian gravity was sufficient to calculate orbital trajectories to land us on the moon. No need to invoke general relativity to tackle that challenge. But we would consider GR a better theory than Newtonian gravity, no? It's a matter of understanding when and where the framework breaks down; which one is more correct and which one provides a simpler, more user-friendly method to calculate.

It's the same here; Maxwell's result demonstrated that light is a wave. Then, the discovery of the photoelectric effect yielded issues and inconsistencies which manifested in the development of an entirely new framework (quantum mechanics) which successfully yields an explanation and tools to calculate -- and gives us wave-particle duality. However! -- I work on infrared instruments, and nobody uses quantum optics here; regular old Zemax is good enough, thank you very much. Why bring in something so complicated when regular ray/wave optics will do?

KVL is a step back; an even further simplification which assumes a conservative electric field. This assumption breaks in some cases (as mentioned earlier), but is a useful approximation for most circuits we see in our day-to-day lives. KVL is a useful tool if it provides useful results; we should understand where it breaks down so we aren't caught pissing into the wind on a £100k deliverable.

And that's the nutshell of my point -- sure, both are "valid," but only up to a point, and we need to have a good understanding of where that point is.

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