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Comment by smolder | Hacker News Reader

As someone familiar with electrical impedance, I don't like this article. It's trying too hard to sound smart.

I just find this an interesting comment. Having an electrical engineers education, there is this interesting repetition of formula which is unmistakable.

First you learn the physical equations, mostly applied to sound interestingly. Then at some point you learn about transmission line theory and maximum power transfer theory. Lastly, you get introduced to Maxwells equations, and how they produce the phenomena you’ve been learning about for years.

Unfortunately that is where my learning stopped, and I never got an answer to how quantum theory resolves with Maxwells equations, and how it interacts with standard model and special/general relativity.

Honestly I’d love an explanation of the standard model that wasn’t covered with mystery and math. It makes the idea of understanding particle physics impossible.

Unfortunately, in my experience the more advanced/nuanced/complete of an explanation of physical phenomenon you want, the more math heavy and abstract the "real answer" becomes. Quantum Electrodynamics is some beefy stuff, the math is gnarly, and it is built on an increasing pyramid of mathematical reasoning and intuition as well as the steps of physical reasoning and intuition that you mention.

Remembering my graduate physics days im astounded that i was able to understand it, and am unable to really follow it now, as that higher math has gotten preeeety rusty.

Feynman diagrams are the attempt to loop back around and represent this field without all the math, but my experience was you have to have done the math first otherwise they are just so much arcane heiroglyphs. the wikipedia illustrates this well, where you can see a relatively clear diagram and corresponding equation, but i recall whole pages of a notebook to get one _line_ of an equation down. https://en.wikipedia.org/wiki/Quantum_electrodynamics#Feynma...

I say all of this not to suggest a clear explanation is impossible, but it sure wouldn't be easy. Love to see it though.

The whole article appears use a very loose philosophical definition of "impedance". As a mechanical engineer, none of the mechanical examples are correct either when there are real-world examples that actually meet the more strict technical definition of impedance matching, mass-damper systems in skyscrapers is immediate example that comes to mind.

Is gearing up or down, with a fixed power budget, a valid example in the strict sense? Genuinely asking.

That's a pretty decent example IMO.

No. A gear train is just a transfer of force/torque. It's analogous to a simple lever for rotational motion. Mechanical impedance is almost always referring to harmonic forces (think of spring systems and structural dynamics). Impedance in fluids also fall under mechanical impedance but it's usually classified separately as acoustic impedance.

I think what they're getting at, and is valid, is how the speed/torque relationship is similar to voltage/amperage. There's nuance which can separate those ideas.

Mass damper systems were really important in cars too before we had deep simulations of structures. Putting some loosely coupled weight in some spot to keep the whole thing from vibrating was a breakthrough.

It's just the transformer example does not sit correctly inside the EE domain definition of impede. Once you understand that word is not locked up to the EE domain, everything is fine (except in the EE world of course).

The first three examples they use are filters.

The abstraction of impedance matching should be to "tune things to make them more efficient in their usability".

Their examples don't sit with impedance matching to me. They're all conversions or filters. The first thing was either not usable or they purely chopped off a part, not pointed it in the right direction.

In fact, the examples more or less all sit in a group in which impedance matching does not belong

Edit: the car transmission I'll give since there's a power vs speed decision that needs to be coupled

Upon further reflection, I realize there's two "impedance matching". I, and other EEs, will assume I mean the complex conjugate matching to redirect power toward load.

The author is making the argument about minimizing reflections across a medium. The trumpet, and AR coating land. The other points are more tortured. The transformer example in particular invites nitpicking.

Reading this was a relief, I've only got a hobbyist's knowledge of impedance matching in the electrical sense and felt like I was going crazy... Good to know I'm not alone

Anything from a funnel to a reduction gear on a ship is an example.

Does low verbalization imply that a concept isn't widely known?

Or is this blog post, itself, an example of impedance matching?

Just read this article as well and thought the same. Quite a bit disappointed.

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