@antimony the real part of magnetic impedance is called magnetic resistance which is not the same as normal resistance (electrical resistance) but does server a similar function (dissipates energy as heat)
@antimony electrical impedance, the kind your used to, describes electrical current and voltage as it moves around a circuit through wires made of copper and components like inductors and capacitors as your used to
@antimony however mangentic impedance is what you'd use to ddescribe similar things (but they are physically very different) in a magnetic circuit
@antimony in a magnetic circuit the wires are replaced with iron which conducts magnetic fields rather than electrical fields through it and what acts like a capacitor or an inductor in such a circuit looks a bit different than what those things look like in an electric circuit but behave similar within the analogy
@antimony its not really used all that often honest, but there is some sort of analysis where it is useful, I see it used in radar analysis a lot where they want to calculate how a material will absorb the field
@antimony you know how if you have an inductor and it uses a ferrite core, particularly at high frequencies beyond the capabilities of the core, the core will heat up and get hot?
@antimony well in the electrical world what would would happen is we call that ESR, effective series resistance.. what that means is if the inductor is heating up we would see that as if the inductor had resistor in series with it at that particular frequency, if we measured it with a current meter it would look exactly like a resistor despite there being no resistor
@antimony however if we viewed the core as a magnetic circuit, then we would describe it as the core material itself have a complex impedanceto the magnetic field propagating through it, which likewise would have a magetic resistance
@antimony basically because gold or whatever is being smelted has a magnetic resistance it will convert the energy int he changing magnetic field into heat and melt
@antimony the equivelant of that with an electric field would be if you just hooked a car battery up to a piece of metal and used its electrical resistance to heat it up and melt it by putting regular current through it
@antimony complex permiability and electrical resistance are often the two major components at play, but there are others that are rather nuanced and complex
@antimony the three types of loss is "static hysteresis loss", which is loss that occurs if the material becomes magnetized across each cycle, this loss only applies to ferromagnetic material like iron. then there is also some sort of wall current and spin loss that i dont really understand which is called residual loss..
but the main component of loss in most materials is a combination of complex permiability and electrical resistance. That is the eddy current stuff you were talking about but best not to think in terms of eddy current if your talking magnetic circuits in my opinion
@antimony if you think of things in terms of magnetic circuits think of the magnetic field flowing through the material as being the same idea as a current flowing through an electrical circuit
@antimony reason im in here asking questions is im writing a blog aritcle explaining all this and wanted to make sure i had the right equations
@antimony the article is intended for people like you to understand and I dscribe all sorts of "electrical circuit duals".. and this is the magnetic circuit dual
@antimony one really interesting thing about magnetic circuit duals is that the main units are flipped.. the "current" in a magnetic circuit is measured in volts and the "potential" is measured in ampere
@antimony yea all the equations look very similar but they are all turned on their head :)
@antimony me too which is why i spent the last week studying this, it is new to me too as of a week ago
@antimony you will probably like the blog post once I'm done with it.. i have a half-finished draft up on my beta site right now but it isnt complete so may not be great for you and may have some errors until im done with it
@antimony the normal blog you drop the beta in the url which is where you normally want to go as i dont always update the beta site at all, it only changes when im renovating
@antimony but seriously check back in a few days when i actually finish the part on magnetic circuits, ill be adding a lot more content on magnetic circuits before publishing.
@antimony no problem.. when i first realized it was a thing i didnt know that actual physicists had proved out the ideas.. when i told my EE friends they thought i was wrong and nuts.. then i realized it was a real thing and my ideas were proven out long before i had them in more detail than my original thoughts, that was a week ago and ive beensstudying and writing about it since then
@antimony here is the wikipedia page that talks about it, though i think it does a really poor job explaining it: en.wikipedia.org/wiki/…
@antimony its kinda cool when you realize what a capacitor and an inductor (or rather their analogous counterpart) is in the model
@antimony they are sort of their opposites of the electrical one.. in an electrical capacitor you have two thin wires that attach to two plates made of the same material as the wires, and then with a resistor in the sapce between them
@antimony in the magnetic circuit its similar in that it is two thin magnetic wires (iron) coming to two big plates (also made of iron) but instead of the space between them being a high resistance (electrical or magnetic) it is low resistance, so the space between is filled with iron too.. basically the opposite of an electrical capacitor
@antimony a magnetic capacitor stores magnetic flux jsut like an electric capacitor stores energy in electric field
@antimony now whats really interesting to me though is the magnetic inductor.. just like an electric inductor stores energy in magnetic flux a magnetic inductor stores energy in an electric field.. to make one of those you would take one of the iron wired and wrap some copper wire around it to make a coil and then on the two ends of the coil you would put a regular electrical capacitor..
so a magnetic inductor is still an inductor but in the reverse orientation where the magnetic wire is where the ferrite core and the leads of the inductor form the capacitor part to store the electric field
@antimony hopefully my paper will help when im done writing it. Honestly the material that exists on this is very hard to follow and it really doesnt explain things well the stuff I could find.. thuis why i invested some much time in this article
@antimony so sadly unless you find a better source (and if you do let me know) you may need to rely on my blog post when its done
@Azmuth say the h index is 5. This tells you that the person has 5 papers with citations of at least 5. And all the rest of the papers have citations less than 5
Okay, so my friend just texted and asked if it's just half the distance from the Earth to the sun, since the sun and the Earth both pull with the same force
@JohnRennie So the question was: $4H_1^1 => \alpha + 2e^+ + energy$. It was asked that this reaction represents? (1) $\beta$ decay (2) $\gamma$ decay (3) Fusion (4) Fission
well... it looks out of place considering every single other question is very straightforward. Idk, I've never had to do this much algebraic equation in one worksheet, but I guess first time for everything?
These are generally used to describe electromagnetic fields inside materials. As the fields inside depend on how the material responds to the external field.
It might be because once you're out of school there isn't a huge change up as you go into the next year, at least not if you're working, so the years feel less distinct
Quick question, when we quantise a vector or spinor field (or more generally anything with more than one component) do we produce a quantum field operator for each component or does the entire object become one operator? I'm about 90% sure it's the former, which would immediately solve another problem I've been wondering about