29 ms·

But good sir, what is electricity?

• anthk 2y ago
  I used to read W. Beaty, the guy from http://amasci.com/ http://amasci.com/ Still, getting electricity right is not easy.
• ok_dad 2y ago
  My favorite thing about electrical theory is that all this business about flow of energy going from + to - is the idea of "electron holes" flowing, instead of the actual electrons! Basically all of electronics and electricity uses hole flow convention. It seems weird to me we don't use electron-flow convention (aka: reality), but then again I'm a weird guy.
  • snailmailstare 2y ago
    I had a similarly funny discussion with a proper engineering student on refrigeration insulation and why it isn't more natural to express it similarly with temporarily trapping cold given the inevitable nature of heat/entropy.
    • criddell 2y ago
      I remember when I was very young I asked my dad if a refrigerator works by moving cold into the box or heat out of the box and he told me it was the latter. It’s a strong memory because he also said something to the effect of that being a good question and at that age, comments like that had an impact on me.
  • jeffwass 2y ago
    But that’s because of historical precedent, if you weren’t aware of this then congrats for being one of today’s lucky 10,000! Ben Franklin arbitrarily picked the positive anode as the starting point when coming up with the idea of electricity flowing, long before we had any understanding of atomic theory. It wouldn’t make sense to just invert everything after we discovered that electrons are the actual fundamental charge carriers.
  • ysofunny 2y ago
    It seems to me like it's an artifact of how it was all discovered and initially implemented. like scientists didn't realize electrons were flowing in the opposite direction, but engineers already had working electrical devices
  • at_a_remove 2y ago
    I have expressed this repeatedly: the assignation of a negative value to the electron and a positive value to the proton has probably slowed humanity by a decade.
    • dotancohen 2y ago
      Anybody who needs to know this detail to design or repair a device, already knows it. There are no simple enough devices where this is relevant for casual repair or modification. You can fix your DC devices such as cellphones and your AC appliances such as refrigerators, and even design your own phones and refrigerators, without knowing in which direction the fundamental particles flow.
    • srean 2y ago
      Could you give one example
      • at_a_remove 2y ago
        In terms of pedagogy, it is a problem. I started tutoring other kids in grade school and eventually got paid for it as a side gig later in life. If I ended up covering electronics and/or general electricity, I saw the same thing I saw as an undergrad taking EE courses: confusion. A lot of people found the situation counter-intuitive. It required extra mental labor for them. Hence, multiplied against millions of people, there's overall lost time. And this isn't just in young people, either. Knew a guy who swore up and down that the "electron holes" really represent positrons. Bad notation, weird syntax, poor choices in variable names, and so on, all of these are a collective drag which could be streamlined away.
        • srean 2y ago
          Seems a pretty trivial change, like, hot water's on the left tap not the right tap. Humans are more than capable of handling that minor conceptual change. Life routinely throws far more challenging changes to adopt to. Nothing fundamentally changes because of Franklin's incorrect guess. The postit sticker goes "there " instead of "here" kind of a thing. Certainly not as grandiose and melodramatic as putting humanity back by a decade.
  • card_zero 2y ago
    The terms are due to Ben Franklin: We say B is electrised positively; A negatively: or rather B is electrised plus and A minus ... These terms we may use until your philosophers give us better. Here A and B are Franklin's buddies, standing on insulating plates while one of them rubs a glass tube with a piece of, if I remember rightly (can't find the proper source), "buckskin". Then they reach out to join hands and a spark crosses the gap. Problem is, it isn't even clear from the experiment which of A and B really was negatively charged, because it turns out the charge depends on the nature of the "buckskin" (or whatever term he used), and how hairy, furry, or possibly even leathery it was. The resulting charge could be positive or negative, depending. So he defined the terms, but didn't even clearly assign them to direction of electron flow. Edit: the ambiguity is shown in this picture: https://en.wikipedia.org/wiki/Triboelectric_effect#/media/File:Triboelectric-series_EN.svg https://en.wikipedia.org/wiki/Triboelectric_effect#/media/Fi... Here leather is above glass, and fur is below it. He was definitely rubbing glass with something like leather or fur, but the resulting charge depends on where in the series that thing was relative to glass.
    • saghm 2y ago
      As usual, xkcd has a relevant comic about this: https://xkcd.com/567/ https://xkcd.com/567/
      • 3eb7988a1663 2y ago
        This makes the robot apocalypse happen at an increased rate. All the advancements made without this stupid error infecting everything.
      • card_zero 2y ago
        Found it from the horse's mouth, finally: "We rub our tubes with buckſkin". https://archive.org/details/experimentsobser00fran_0/page/17/mode/1up?q=%22We+rub+our+tubes+with%22 https://archive.org/details/experimentsobser00fran_0/page/17... Don't know where Randall get "silk" from.
        • ThrowawayTestr 2y ago
  • kqr 2y ago
    > about flow of energy going from + to - is the idea of "electron holes" flowing You mean flow of charge. My favourite thing about electricity is how the actual energy is transferred on the outside of the wires, in both the directions of positive and negative charge. Resistance is the portion of the energy that accidentally enters the wire. The energy flux inside the wires -- and on the surface of the wires -- is zero. Just outside their surface it is very high. A capacitor wouldn't work if the energy came from its poles. No, the energy used to charge it enters from the side. This is so counter-intuitive!
    • benterix 2y ago
      > accidentally Well, we may see it this way, but there's nothing accidental in it, it's juts an inherent property of every conductor (except superconductors).
    • marcosdumay 2y ago
      Charge flows on the same medium as energy. There's current on the equation of electrical power for a reason. That bullshit model about electricity flowing around the wires is good for generating Youtube engagement, but it doesn't represent the actual physics, makes things impossible to calculate, doesn't lead to any intuitive understanding, and makes things impossible to learn. Or, in other words, the model is bullshit. DC current flows entirely in the wires (up to at least "parts per billion" precision), as does energy, because energy flows at the same place current flows. AC current leaks. Everybody knows that, how it leaks is well known, and there are plenty of resources to calculate almost everything around it.
      • jmb99 2y ago
        Exactly. If energy flowed around the wires and resistance was “the portion of the energy that accidentally entered the wire” then larger wires would have larger resistance (due to a higher chance of “stray energy entering the wire”) than smaller wires, which is clearly incorrect. It really is a terrible model in almost every way.
        • 2y ago
  • choxi 2y ago
    It’s weird in semiconductor physics too because the electrons flow uphill through voltage potentials
  • veunes 2y ago
    And it's wild for me that we've been teaching it this way for so long just because of a historical guess made before electrons were even discovered
• Xcelerate 2y ago
  > Most simply, it [electron] just exists as a particular distribution of an electrostatic field in space. Best simple description of an electron I think I’ve heard yet. I wish we would drop all the dumb analogies. From a kid’s perspective (at least what I can recall from high school), these macroscopic analogies mislead you into thinking the laws of physics work differently than what humanity’s best models of physics actually predict. For instance, I never liked the sense of “arbitrariness” I felt while learning about the periodic table in K-12 school. The diagonal rule. Hund’s rule. The exception to Hund’s rule. And so on. Don’t even get me started on organic chemistry. But if someone had told me “Forget about billiard balls and wave/particle duality. Our best models consists of solutions to simple and beautiful equations that are extremely difficult to solve”, then that would have made a lot more sense to me. The author of the article describes the truth as “weird math”. I don’t think that’s necessarily the case. Unitarity is aesthetic—it just “feels right”. The correspondence of atomic orbitals to irreducible representations of symmetry groups is beautiful. Why don’t we teach that to kids? You don’t have to go into the mathematical details of group theory, but just let them know these odd shapes originate from symmetry constraints. Much better than my reaction to seeing an illustration of a d_z^2 orbital in high school. I remember thinking “What the heck is that? This subject makes no sense.”
  • deleted 2y ago
    [deleted]
  • aeonik 2y ago
    I agree that we should teach the quantum basis of things earlier. I just think a lot of people don't know it, and we don't have a good curriculum for kids to start with. We'd also need to revamp some of the math, chemistry, and physics curricula to build on the quantum basis of things.
  • fc417fc802 2y ago
    > I wish we would drop all the dumb analogies. They're incredibly useful tools for thinking about things. You don't need or want QM to perform most reasoning tasks. Even MO is often overkill. I agree though that we should lead with the truth - that these models you're being taught are useful abstractions but ultimately wrong. That each successive model brings with it more accuracy and nuance but is more difficult to comprehend. A particular strength of that approach is that after making it to QM at the end it leaves you wondering what's next. It really drives home the point that the map is not the territory and that all we as humans can ever actually have is a succession of maps. > Forget about billiard balls and wave/particle duality. Actually that one is rather important. QM wave functions really do collapse. Things really do switch from behaving like a wave to behaving like a particle. This fact has significant effects on behavior. > these odd shapes originate from symmetry constraints Well they might fit those constraints, but can they really be said to originate from them? Is there actual cause and effect there? The answer to that would require understanding what gave rise to the phenomenon to begin with.
• _factor 2y ago
  I’ve always wondered if the electrons bound to a nucleus are somehow bound to the element they were attached to. Changing an element from Hydrogen to Helium or any other variant of conversion seems like it breaks an especially solid confluence. Each proton determines the atomic number, and there is a corresponding electron for each proton after all. They may float around the universe, but could they still “belong” to the element they were formed with, bound to be impacted in some way when that element converts to another (in a stellar reactor for example). This would mean electrons are somehow unique most likely, but stranger things have been observed.
  • aeonik 2y ago
    I'm not sure exactly what your imagining, but there are two principles that are related to your idea. 1. Particles are indistinguishable from each other. It's a very deep principle, i.e. a lot of stuff relies on this being true. 2. States and particles can absolutely be entangled ("bound") to each other, but it tends to be pretty fragile. https://en.wikipedia.org/wiki/Indistinguishable_particles https://en.wikipedia.org/wiki/Indistinguishable_particles https://en.wikipedia.org/wiki/Quantum_entanglement https://en.wikipedia.org/wiki/Quantum_entanglement
    • fc417fc802 2y ago
      To be fair, what he proposed isn't (immediately obviously) mutually exclusive with your points. If it were true it would be almost impossible to detect experimentally. So it gets tossed on the stack with all the other complex-and-unfalsifiable theories for which no evidence exists. It might make for an amusing sci-fi plot though.
      • MalbertKerman 2y ago
        > To be fair, what he proposed isn't (immediately obviously) mutually exclusive with your points. If it were true it would be almost impossible to detect experimentally. The obviousness or lack thereof is subjective, but the exclusivity is firmly established. The absolute indistinguishability of particles is deeply woven into quantum mechanics; you don't get a Pauli exclusion principle without it, for example. If the particles remembered their previous lives, and an electron that used to be tied to an iron nucleus weren't completely identical to one that used to be stuck to a carbon nucleus, all of quantum mechanics as we know it would be impossible.
• doop 2y ago
  Why does this otherwise excellent series always depict electrons as red and protons as blue when everybody knows it’s the other way round?
  • immibis 2y ago
    I thought everyone knew that neutrons are blue and electrons are yellow.
    • diegoperini 2y ago
      I refuse to believe neutrons can be any color other than white.
  • MathMonkeyMan 2y ago
    Electrons are blue and oxygen is red. Don't be ridiculous.
  • sergj 2y ago
    If you have ever looked at an old transmission electron microscope with a viewing screen, you know electrons are green ; )
• simpaticoder 2y ago
  Great article! I particularly like this paragraph: >It’s important to note that while the charge equalization process is fast, the drift of individual electrons is not. The field propagates at close to the speed of light in vacuum (circa 300,000 km/s); individual electrons in a copper wire typically slither at speeds measured in centimeters per hour or less. A crude analogy is the travel of sound waves in air: if you yell at someone, they will hear you long before any single air molecule makes it from here to there. So basically electricity flows like a Newton's cradle. But this leaves one nagging question: what is the nature of the delay? This question also arises when considering the microscopic cause of index-of-refraction for light[1]. If you take a simple atom, like hydrogen, and shine a light on it of a particular frequency, I understand that the electron will jump to a higher energy energy level, and then fall back down. But what governs the delay between these jumps? And also, how is it that, in general, light will continue propagating in the same direction? That is, there seems to be some state-erasure or else the electron would have to "remember" more details about the photon that excited it. (And who knows? Maybe the electron does "remember" the incident photon through some sort of distortion of the quantum field which governs the electron's motion.) The same question applies to electron flow - what are the parameters that determine the speed of electricity in a conductor, and how does it work? 1. 3blue1brown recently did a great video describing how light "slowing down" can be explained by imagining that each layer of the material introduces its own phase shift to incoming light. Apparently this is an argument Feynman used in his Lectures. But Grant didn't explain the nature of the phase shift! https://www.youtube.com/watch?v=KTzGBJPuJwM https://www.youtube.com/watch?v=KTzGBJPuJwM
  • marcosdumay 2y ago
    > But what governs the delay between these jumps? What governs the delay between one ball hitting the cradle and the opposite ball going up? It's the electrical equivalent of the same thing. Specifically, electricity is delayed by the material absorbing it "elastically" for a short time before emitting it back. This is usually modeled as a capacitance and inductance on the medium. > And also, how is it that, in general, light will continue propagating in the same direction? It actually doesn't. It mostly follows the medium. That's why you can bend your wires and they keep working. But if your question is why it doesn't go "backwards", they go, but there's an electrical potential there pushing your electrons on the other direction.
• k__ 2y ago
  I got told what electricity is in primary school, in middle school, in high school, and in university. Every time I understood it less. I even watched some videos where people interviewed physics professors, to explain what it really is, and the explanations only got more convoluted. Seemingly not because those people were bad at explaining, but because if you want to explain it as correctly as possible, it just isn't intuitive at all.
  • ekianjo 2y ago
    it's confusing because all of the words we use in the field make it seem like it's akin to water flowing (current) whereas the physical phenomenon is far beyond the movements of individual electrons.
    • srean 2y ago
      It's not a bad analogy if you also consider the pressure wave. That travels a whole lot faster than the water molecules.
    • H8crilA 2y ago
      The problem with (or the advantage of) the water flowing analogy, or even more broadly the discrete element model, is that it explains reality good enough to be used in most practical situations. Schematics are ubiquitous, yes they are "fake", but they are also usually "correct enough". Kind of like the incorrect Bohr's model of electrons orbiting the nucleus actually does explain the emission spectra (up to a point). But there is an accessible video that explains electricity pretty well. Veritasium - The Big Misconception About Electricity: https://www.youtube.com/watch?v=bHIhgxav9LY https://www.youtube.com/watch?v=bHIhgxav9LY There is one commonly used concept that requires understanding electricity correctly, and not just as a combination of waterhoses and gizmos. It's impedance, and it directly corresponds to the "controversial" experiment that Veritasium is proposing in his video. Impedance breaks the pipe-of-electrons analogy.
      • BenjiWiebe 2y ago
        Are you sure we can't explain impedance with the water analogy? You would have to start with alternating current water, since "DC" water maps to DC, where impedance =resistance. Once you've got alternating water, you can add inductance (inertia) and capacitance (rubber diaphragm tanks) and I think it all works out. It's just that we don't have a good intuition for alternating water current so it's not a very useful analogy in that case.
• movpasd 2y ago
  A point not mentioned by the article: the electrons in a metal at room temperature are already moving very quickly due to their thermal energy (at the order of 100km/s) — much faster than the speeds quoted in the article, which is what's called the "drift velocity". This thermal motion is essentially random, and the electrons constantly scatter off the nuclei every which way, so it cancels out and doesn't create a net current. So, it's less than the electrons gently move under the influence of an electric field, and more that it introduced a slight bias in the existing thermal motion. E: To clarify in case it may have been unclear, this is unrelated to the speed of propagation of the electric field, which as the article says is the speed of light.
  • Nimitz14 2y ago
    This feels like a very nice intuition to have thank you for explaining!
  • sfn42 2y ago
    Is this related to how some materials become superconductors at low temperature? Does the slowing down of this electron flux improve the material's ability to conduct electricity or is there some other mechanism at play?
    • khold_stare 2y ago
      Superconductivity is fascinating. I don't know how people were able to come up with the explanations. Crudely, the reduced temperature means less jiggling of the metal lattice. This in turn makes it possible for the nuclei to be pushed around by electrons to form essentially sound waves (phonons) in the lattice (think of the lattice compressing and expanding due to interplay with electrons). At a certain temperature and therefore a certain frequency of lattice oscillation, electrons pair up to form "Cooper pairs" - they move in concert due to the lattice movement. What's crazy is that cooper pairs become a sort of pseudoparticle, and their quantum behaviour is different to regular electrons. Cooper pairs have integer spin (as opposed to half-integer spin), so they no longer obey the Pauli exclusion principle and all the electrons in the entire material basically form one giant condensate that extends through the whole material and can all occupy the same lowest energy quantum state.
• iandanforth 2y ago
  For introductory articles like this I also find it helpful to know that the whole positive / negative thing is arbitrary. In fact the assignment of "negative" to electrons arise due to a mistaken interpretation by Benjamin Franklin of one of his experiments. So if you're wondering why gaining the primary mobile charge carrier makes things more negative blame Ben Franklin!
  • FabHK 2y ago
    I wouldn't call it "mistaken". It was an arbitrary choice at the time, nothing but a naming convention.
• mackman 2y ago
  As someone who studied physics and electronics for many years, I still appreciate an article like this for reminding me how profoundly weird science is. Working day to day with the equations and practical applications of electricity gives you a false sense of confidence that we actually have any fucking clue what’s going on.
  • ffsm8 2y ago
    *how profoundly weird reality is. (◕‿ ◠) Or is it "how profoundly weird this simulation is"? we'll never know!
• djsamseng 2y ago
  There's also the field theory of electricity: https://youtube.com/watch?v=bHIhgxav9LY https://youtube.com/watch?v=bHIhgxav9LY It’s an eye opening alternative explanation to the electrons flowing like a chain theory of this article.
• jvanderbot 2y ago
  > Pay no mind: it’s enough to say that most nuclei on Earth were formed through nuclear fusion in stars and won’t undergo any change on the timescales of interest to electronics — or to terrestrial life. It's impossible for me to understate how awesome this is. And how hard it is for me to truly grok.
  • frutiger 2y ago
    Yes, and in particular that it's in all the "ordinary stuff" around you - wood, air, glass, sand. Reality is truly extraordinary upon any closer examination.
• karaterobot 2y ago
  This was pretty clear and readable, I guess. But the most succinct explanation of electricity that I know of is from Stephen Leacock: > Electricity is of two kinds, positive and negative. The difference is, I presume, that one comes a little more expensive, but is more durable; the other is a cheaper thing, but the moths get into it. And that's sort of all I need to know.
• jimbob45 2y ago
  In pop-science articles and videos, the concept is usually illustrated using the dated but intuitive model developed by Niels Bohr around 1918. The model envisions electrons that travel around the nucleus in circular orbits: Please stop teaching the history of what we used to think the atom looked like. We’ve reached the point where we spend 99% of the material teaching what we know the atom doesn’t look like and very little on what it does look like. Even this author offers a picture for what it doesn’t look like and nothing for what it does. Physicists should know the value of a good picture/mental model better than anyone else. I challenge you to go on Wikipedia and find the article/space for the current understanding of the atom. Was that hard for you to find? Would a curious high schooler have enough information within that article/space to learn everything you now know (textbooks are too expensive and inaccessible for high schoolers to rely on, physics websites are hit/miss). Is this how you would prefer to have been taught?
  • oh_my_goodness 2y ago
    The picture of electrons sitting in states (or the empty states without electrons) is not used for historical reasons. It's used because the next level of explanation requires partial differential equations.
• erehweb 2y ago
  There is a story of a student taking an oral exam at Oxford or Cambridge many many years ago. Examiner: "What is electricity?" Student: "Oh, I do know, I mean I used to know, but now I've forgotten." Examiner: "How very unfortunate. In the whole of history only two people have known what electricity is - the Creator and yourself. And now one of the two has forgotten."
  • dmos62 2y ago
    I've heard it said that we don't know what electricity is or how it works. To what extent or in what sense is that true?
    • CamperBob2 2y ago
      That goes along with the other old saying, "All models are false, but some models are useful." We don't know what electricity is in the sense that if you keep asking "But why does object X cause (or experience) effect Y?", you will eventually reach a point where we don't know the answer. In that sense, we don't know what anything is. But we can still use it. And because everything we learn seems to become useful sooner or later, it doesn't pay to stop asking.
      • JALTU 2y ago
        I'm not sure that was the point of the poster's question about electricity, because I've heard the same assertion made by science writers and such. Our current BFF, ChatGPT, says the question is about "charge" in that we don't know why particles have a charge. So what is a "charge" and why? Gravity is also presented as a thing we don't fundamentally (ontologically) know about. Interesting! And not disagreeing with the desire to keep asking, nor with the desire to find a final answer. The author of the article puts it fairly well: We don’t have philosophically satisfying insights into the universe at subatomic scales...there’s no straightforward explanation of what a bound electron actually does: it’s not orbiting the nucleus or spinning around its own axis in any conventional sense. Most simply, it just exists as a particular distribution of an electrostatic field in space.
• benterix 2y ago
  > The field propagates at close to the speed of light in vacuum (circa 300,000 km/s); individual electrons in a copper wire typically slither at speeds measured in centimeters per hour or less. It would be worth mentioning why it happens as it's quite interesting.
  • AlienRobot 2y ago
    I'm no physicist, but if I remember correctly, light is some form of electromagnetic radiation, which means EMR travels at speed of light. In that case, it's not surprising that an electrostatic field can travel at similar speed. From my understanding the quote is talking about electrostatic effects that occur when electrons move to fill a void/go away from a negatively charged area. Since the force that makes electrons repeal each other is very weak, I think it makes sense. But note that it mention "a single electron." Voltage deals with a difference in immense scales of electrons, so I assume the effect and speed would be different in practical cases.
• alabastervlog 2y ago
  On a whim, I bought a book called There Are No Electrons at a used book store, some years ago. The idea of the book is that we spend lots of time teaching students various incorrect and inconsistent models for how electricity works, that also don’t optimally build intuition for working with the stuff. The book’s remedy is to say “forget all that: here’s a wrong model that is good at building intuition for working with electricity, and if you’re not planning to go for a physics PhD, that’s much better for you than the other wrong models” I don’t know enough about electricity to evaluate whether this was a good idea or well executed, but it’s an interesting approach. https://goodreads.com/book/show/304551.There_Are_No_Electrons https://goodreads.com/book/show/304551.There_Are_No_Electron...
  • xandrius 2y ago
    Could you give a gist of such a wrong model?
    • holoduke 2y ago
      The classical model of an atom with circulating dots representing electrons. I believe those dots must be more like waves.
    • tigerlily 2y ago
      Or the plum pudding thing. Oh, and phlogiston.
    • genewitch 2y ago
      If that's the book I am thinking of everything an analogy with little aliens called greenies that bounce on trampolines. I couldn't get through it. I got to just past the holes part. It is written well, so might be worth a shot.
      • TheSpiceIsLife 2y ago
        Angry pixies.
  • therealdrag0 2y ago
• nayuki 2y ago
  > what is electricity? My favorite answers are: * http://amasci.com/miscon/whatis.html http://amasci.com/miscon/whatis.html * https://blog.rootsofprogress.org/the-significance-of-electricity https://blog.rootsofprogress.org/the-significance-of-electri...
• danso 2y ago
  Ever since seeing this time traveling meme [0], I'm constantly thinking about how I would be the worst time traveler ever. Maybe I could explain flight? But not electricity, definitely not the engineering needed to make it usable. [0] https://cheezburger.com/9253930240/this-electricity-business-sounds-like-bs-to-me https://cheezburger.com/9253930240/this-electricity-business...
• thetwentyone 2y ago
  > A crude analogy is the travel of sound waves in air: if you yell at someone, they will hear you long before any single air molecule makes it from here to there. Isn’t this a very good analogy? What’s so crude about it?
• CHB0403085482 2y ago
  Relevant: How Electricity Actually Works by Veritasium ~ https://www.youtube.com/watch?v=oI_X2cMHNe0 https://www.youtube.com/watch?v=oI_X2cMHNe0
• aranchelk 2y ago
  > We don’t have philosophically satisfying insights into the universe at subatomic scales. We have quantum mechanics: a set of equations that are good at predicting the behavior of elementary particles, but that don’t line up with our intuition about the macroscopic world. Our analogies and intuitions are based off of our macroscopic experienced reality, this seems to be an entirely emergent phenomenon based on those strange behaviors described by quantum mechanics. If those insights ever do come, I don’t believe they’ll correspond to anything prewired into our brains or experienced in our lives, and will never be remotely satisfying.
  • crazygringo 2y ago
    > If those insights ever do come, I don’t believe they’ll correspond to anything prewired into our brains or experienced in our lives, and will never be remotely satisfying. I don't know why you'd assume that. Euler's identity certainly doesn't correspond to anything prewired, and yet it's very satisfying. The philosophical insights will be satisfying if they are simple and elegant. Our theory of biological evolution through natural selection isn't remotely prewired either, but that doesn't stop it from being one of the most philosophically satisfying theories we've come up with.
• TheSpiceIsLife 2y ago
  If people are going to bring up Veritasium and AlphaPhoenix, then I'm going to want to say something like: ElectroBOOM and AvE and bigclive have done more to further my understanding of electricity, both theoretically and practically, than everything else combined. https://www.youtube.com/@arduinoversusevil2025 https://www.youtube.com/@arduinoversusevil2025 https://www.youtube.com/@ElectroBOOM https://www.youtube.com/@ElectroBOOM https://www.youtube.com/@bigclivedotcom https://www.youtube.com/@bigclivedotcom
• andrewla 2y ago
  Except in extremely exceptional circumstances, it is not useful to try to reason about the behavior of electrons when looking at electricity. Treat it as electrical fields and you'll be fine. The fields represent reality at the non-quantum scale much better than attempts to model non-quantum reality. As a notable example, macroscopically electricity is totally symmetric - positive current flows the same as negative current does. There are components that exhibit asymmetric behavior but they can be arbitrarily oriented so it doesn't really matter.
  • michaelt 2y ago
    You're broadly correct when it comes to designing practical circuits. But if your aim is to answer questions like "why do different colour LEDs need different resistors" or "what does it mean for something to be a semiconductor" pretty soon people will start talking about 'electrons' and 'holes' and 'band gaps' and 'depletion regions'.
    • andrewla 2y ago
      It is true that this is how we tend to discuss these things, but the important thing in practical circuits (even semiconductor circuits) is how they behave, not why they behave that way. Really there has been only limited success in discovering new semiconducting technologies motivated from first principles -- it's mostly intuition and dabbling and experimentation that has yielded the advancements. To some degree of course motivated by models of behavior, but it's very easy to ignore all the blind alleys that theory has led down. Mostly you're better off understanding that semiconductors work by "magic" and knowing what the response curves look like (or building mental approximations and heuristics) and otherwise just treating things in terms of currents and voltages (and fields at the lower level as necessary).
• netbioserror 2y ago
  Electricity finally made some sense to me when I wrote down the basic high school electricity equations and derived the basic energy and charge units from them. That's how I finally understood that power is energy rate (Joules per unit time), current is charge rate (electrons per unit time), and voltage is energy per unit charge (Joules per electron). Voltage makes a lot more sense as the excitation of electrons; them wanting to jump gaps and go to a lower energy place feels more intuitive in that framing.