The high resistance piece of wire in incandescent light bulbs glows as a result of electrons incoming through a low resistance material being squeezed through (bombard electrons that don’t want to be moved in) the high resistance material with a certain pressure (voltage). We are using the high resistance material to usurp (convert into heat and then into light) the kinetic energy of the electrons in the low resistance material (commonly copper wire).
We do the same thing with electrical heating elements and microphones.
Are we also doing this in electrical appliances from which we don’t expect a certain “end product” (heat, light, sound)? For instance, computers. When we were still using actual physical relays to build logic gates, I can imaging electron flow being converted into the energy (eletrco magnetism?) required to actuate/move the switch inside the relay. But what about today’s transistors? The processing units inside CPUs and GPUs heat up, but that’s a side effect of something I don’t understand. We are not trying to reap that heat. We are after manipulating groups transistors into expressing boolean logic by either giving them a voltage or not.
I know very little of electricity, so please do correct any incorrect assumptions! I’m very eager to learn! 😊💡
You’ll need to learn some quantum theory to really understand transistor since field effect can’t really be explained using other analogies.
Basically because there is water at a high height (high voltage), the height in another pipe changes: Without the water actually flowing through the pipe.
Transistor let you set voltages without passing current through (in the real world, there is current and thus heat being generated as waste, but it’s extremely small compared to the number of switching components there are).
Alpha phoenix https://youtube.com/@alphaphoenixchannel
Has some cool experiments on his channel that explain it a bit more, dont watch the vertasium videos they are kinda bad and misleading in my opinion.
As a electrical egineer i would just pick up a physics/ee book and try to read it and build up a understanding from the simple dc calculations to dc and field theory. The simplistic models make working with real problems easy so you ddont have to use differential equations for everything and think about fields etc for sumple circuits etc.
Thanks! Maybe I’ll take a break from programming and pick up an ee book! 😊
Not to pick on them too much, but I have been deliberately avoiding Veritasium because he’s too “clickbaity”, showy and flashy. I’m not very comfortable with that.
You mean electromagnetism? We use electromagnetism all the time. That’s how we get electric motors.
The one thing I’ve learned about electricity, is that the more you learn about how it works, the less sense any of it makes.
While I understand the need to simplify things for children who do not have enough prerequisite knowledge to otherwise understand science, “dumbing it down” is what has made me - and many more - believe that electricity works just like water. This has made it so difficult for me to “transition” into seeing electricity for what it actually is: electric fields generated by slightly moving electrons. I shouldn’t have chosen music as a major. 😂
That’s how electromagnetism works. Electrical current consists of electrons flowing “in reverse”
I understand how to wire switches in my house, and that’s good enough for me.
Fair enough! I wired some PC chassi fans to a DC power adapter so that I could power them with the power outlet. And while that’s good enough for me in practice, my curious brain won’t stop bogging me until I learn it all. 🤣
when you’re using a sailing ship, you’re not actually using wind to drive, instead you’re using the energy within the wind’s movement, that’s what you’re using to push the ship forward. the air does not get consumed in some kind of air-eating machine or sth
it’s similar with electricity. the electrons rarely get consumed (exceptions exist, mostly in electrochemistry)
Sweet allegory! Thanks! 😊
I could add to this analogy. Yes, the wind passes from a high-pressure point to a low-pressure one but that’s just direct current. The weather can change, reversing the wind every few minutes (alternating current) and you can still harvest it with a turbine (for example, a lightbulb filament or heater lights up in either polarity) but it wouldn’t help a ship with a basic sail travel to a destination (much like DC motors, it would change direction when polarity is reversed). And then there’s sound, akin to very quick polarity changes where particles never travel very far. It doesn’t carry much energy but the waves travel faster than wind and can be modulated with a signal to carry information. Both wired and wireless electronic communication is kind of like that. (Except wireless is decoupled from the charged particles that create the waves, the disturbances in E and B fields propagate on their own without matter)
Thanks! This reminds me, I’ve just recently read about old oscillators and the cycles, periods and hertz of electric signals. In oscillators, or clocks, that are used in computers, the signal switches between current - no current. Which isn’t the same as switching polarity in AC, but still.
It also reminded me of how insane I find it, that the membranes of speakers - whose vibration is controlled by an electromagnet, if I understand them correctly - are able to vibrate in a fashion that not only makes one sinus wave of one frequency, but sometimes a complex, intricate mixture of sounds, such as when watching a scene from a movie that has soundtrack, ambient sound, speech, explosions, whathaveyou. How on earth can one membrane do that… A piano commonly needs 88 keys whose combination can produce complex harmonies. Speaker membrane: hold my beer.
A piano/guitar string is plucked and then vibrates at its own natural frequency (plus in practice, higher modes aka harmonics/overtones defined by where it’s plucked and mechanical design). Wind instruments are designed to create continuous oscillation from constant flow of air by amplifying reflected waves with incoming air pressure energy (blowing straight into a cylinder won’t work, hence the weird pipe shapes, holes and reeds). Either way, they resonate at their design frequency. So do self-oscillating piezo buzzers. The speaker membrane, ideally, does not have a resonant frequency (responds equally to disturbances at any frequency between 20 Hz and 20 kHz) and needs to be pushed constantly to create sound. Like the membrane of a mechanical phonograph/turntable, the shape of the wave it should create is delivered to it in real time, except electromagnetically. That’s why player pianos need very little data (literal punch cards: one bit per beat and string) to reproduce entire songs as opposed to audio recordings that require samples at decent precision (16 bits is generally good enough) at at least 2x the highest frequency to be reproduced.
so please do correct any incorrect assumptions! I’m very eager to learn!
It is not so much the assumptions. You need a more careful approach. Do not rush from observations to “easy” conclusions.
the kinetic energy of the electrons
The mechanical model does not fit here.
If it were kinetic energy, the outcome would be very weak because of the electrons low mass. Also the electrons do not change their mechanical speed when there is electrical resistance.
Take a good science book that explains the basics and gives you the correct formulas to do such calculations.
Had I “concluded” anything, I wouldn’t have posted in the first place.
Reading up on the subject at my local library is on the agenda. I just have get tired of programming first. 🤣
electron flow is not what transmits energy it’s the electrical field. in AC circuits electrons don’t really get transported from a source to a destination.
the water allegory unfortunately breaks down very quickly. pressure is force per area. voltage is a difference in potential (~charge).
i feel like someone might be better to really answer to your questions. my physics ed is … long gone.
edit: ofc electrical currents (flow/wiggeling) heat up materials through interaction with it. so yeah electrons transmit the energy they get to tge materials.
transistors (and diodes) are black magic to me. i learned to calculate, but never understood the how and why. you might wanna have a look into the avalanche effect, that is at play in a transistor switching. its a good rabbithole for a weekend, i promise!
This is actually incorrect as well, and I’m annoyed at veritasium for this persistent misconception. The flow of electricity is the movement of charge, which is conveyed by the electron. This is what creates the electromotive force, and what does work.
hm thanks for pointing that out. i will have to thonk abt that for longer though.
It’s admittedly confusing because electromagnetism is a unified field theory, and like I said, a bunch of pop-science YouTubers really make it worse. Current is defined as the rate of charge flow through a cross sectional surface of a conductor, which is caused by the electromotive force, which is simply a charge potential. The fields created by moving charge can be used to do work proportional to the current which creates them, but it is fundamentally the current doing the work.
The misconception is that it’s not like one electron zooming down a wire, dumping energy into a sink, but the bulk change in how electrons, and therefore charge is distributed which moves energy around. Think about pushing something with a stick - the atoms near your hand don’t actually need to move down the stick to transmit force.
Thanks! So it isn’t the electrons alone that we make use of, but the electric field that their tiny movements generate?
There’s a HUGE number of electrons in everything with a massive total negative electric charge but almost exactly balanced by protons. That’s why electrons move very slowly in a conductor but still transmit lots of current (electric charge over time).
Accumulating charge in a place is what charging a capacitor or battery is, it creates voltage (potential difference). Charges in an electric field store energy but also their presence/absence can represent data (DRAM and flash memory) and the field has various effects we can use, such as deflecting the beam in a CRT oscilloscope controlling the flow of electrons in an eectron tube or field-effect transistor.
And the current also creates magnetic field with some similar effects (deflecting the beam in a TV CRT) and some different ones (attracting magnets in a motor, inducing current in a transformer’s secndary winding).
Plus, both fields can oscillate a vast range of freequencies and travel in waves, making radio, microwave ovens, vision, UV sterilization, X-ray machines etc. possible (although each of these applications uses the properties of EM waves at specific frequencies differently).
Thank you for the great examples! See, this is yet another misconception that I picked up at elementary school: that “electricity travels at the speed of light”. After having read all the comments, yours included, and done some more reading, it is obvious that it’s the effect of electricity that to us seems immediate - for instance, a light bulb turning on. The propagation of the electromagnetic fields is what’s fast. Am I right?
Yep electrons travel at VERY different speeds through different materials. For instance, in certain semiconductors they can travel millions of times faster than in copper wire, which is why they are used for power amplification. But even in those, a single electron does not travel very far, relative to the distance we transport ‘electricity’ through wires and such.
Yup. When you add an electron to one end of a wire, the change in the electric field will be felt very quickly (high percentage of light speed) across the wire and the electrons, now outnumbering protons, will repulse and want to shed the extra one from any point in the wire.
Like when you add an atom to a sealed gas container.
I mean, to be fair the water pipe analogy is pretty good as the pressure performs work done per unit volume, and voltage is work done per unit charge which takes up a specific volume of the wire.
But you’re right, with A.C. that analogy gets complicated unless supposedly you had water going back and forth in the pipe, but that is still transmitting energy like a wave does.
like any good model it has it’s scope. inductivity and capacity are out of scope. electrical current is not electrons pushing each other as a longitudinal wave in water could make it wiggle in a pipe. as soon as something stops to make sense in the model we need a new model.
I always see analogies as effective at their chosen level of resolution (similar to your scale).
At dinner-table-conversation level, or 5 year old kid level, these water analogies work.
If you need to actually produce something, they’re completely useless.
But for most stuff/people, Newtonian analogies work surprisingly well, so long as we always qualify it with “remember, this isn’t actually how it works, this is just an analogy to get you closer to how it works”.
This is a reasonable description of heating elements and incandescent lightbulbs.
Microphones, generators, speakers, and motors typically involve an electromagnet and a permanent magnet. For speakers and motors, electrons moving in a circle generates a magnetic field, which pushes against the permanent magnetic field of the permanent magnet. For microphones, and generators, it’s kinda the opposite: a permanent magnet moving near a coil of wire generates a magnetic field.
Transistors, which are the basis of modern CPUs, rely on the need for loose electrons to be around for an electric current to flow. In a carefully crafted setup, you can end up with a current flowing along one path depleting the loose electrons needed for a flow along another path to form. This creates a kind of “electric switch”.
Heat is generated in all of these processes, but it’s generally an unwanted but unavoidable byproduct, similar to heat produced by friction in a mechanical system.
I’m not sure what you mean by “EFFECTS of electron flow” vs “electricity”.
What tends to matter is the electromagnetic fields and how they change. Often we use electrons flowing in a piece of metal because they are easily influenced by electromagnetic fields, but also when there is an electron flow in a wire, the shape of that wire can result in different electromagnetic fields. However, I think it’s worth mentioning that electrons and wires are just convenient for controlling the electromagnetic force. It’s possible to have electromagnetic effects without either (for example, lightning and static electricity are electromagnetic effects that don’t involve conductors, and light is an electromagnetic effect that doesn’t rely on electrons).
I’m happy to answer more questions, I’m trying not to launch into a whole physics lecture lol but I sure can if you like.
Thank you for the elaborate response! Are radiowaves also electromagnetic fields, or are those something completely different?
What I meant by the vague title was whether we actually consume or use the electrons themselves or simply reap the biproducts of some kind of manipulation that we do with them. I guess we do both, then, since it seems like it’s the acutal current in one node of a transistor that frees up/depletes the electrons of another node/path, as opposed to heat and light, where we instead reap some biproduct?
Are radiowaves also electromagnetic fields
Radiowaves are a color of light that we can’t see. Technically “light” typically only refers to visible colors, and we call everything else “electromagnetic radiation”. Radio waves, microwaves, and infrared light are past the red end of the rainbow, while ultraviolet, x-rays, and gamma rays are past the violet end of the rainbow. All of these are self-propagating ripples in electromagnetic fields.
whether we actually consume or use the electrons themselves or simply reap the biproducts of some kind of manipulation that we do with them
It’s very difficult to actually destroy an electron. When I said the electrons are “depleted” in a transistor I meant they are pushed somewhere else. Electrons can be pushed and pulled by electromagnetic fields, so in a transistor one current makes a field that pushes electrons out of the region where they would need to be for the other current to use them.
In all cases it’s the electromagnetic fields that actually do the work.
If you want to know about electrons actually being destroyed, an electron will annihilate with a positron (antimatter electron) releasing some gamma rays. There are some medical applications for radioactive material that produces positrons which annihilate to produce gamma rays in this way, and then they can detect the gamma rays.
Thanks for all the clarifications! It’s mindboggling and fascinating how we found out about all this, came up with concepts and pointers - language - to express and describe it all.
For the fundamental concepts of electromagnetism, see ‘Maxwell’s Equations’. Personally, I prefer looking at the differential equation versions to understand the interplay between electro- and -magnetism and how that relates to light/electricity/so many things
Everything is part of the EM (electromagnetic) spectrum - light, radio, microwaves (which were originally/still used for radio) etc.
https://www.narodnatribuna.info/lists/pictures/electromagnetic-spectrum-diagram-for-kids/
Check your library for the Great Courses Electrical Engineering for Everyone
You’re also stepping into the realm of Quantum Physics, which is what helped me start to understand electricity at the quantum (i.e. electron) level.
Taking the Quantum Leap is just about the best intro I’ve come across for an intro to Quantum Physics. Super easy read, life-changing, paradigm-shifting consequences.
The Great Courses also has Understanding the Quantum World (hopefully your library has it).
Katching😉
Is how I say thank you for all this to a persons whose display name is onomatopoeia. 😁
Go to a library and ask the reference desk/research desk if they have any introductory textbooks on electrical engineering.
maybe also something more basic for general physics.
They’ll have something that fits your needs, or at least know where to find it.
IN THIS ECONOMY?! /j
Thanks! This has been on my mind for a long time, but at the moment, I’m learning how to program. I don’t know how to squeeze in yet another subject as a hobby project. 😅 Maybe when I get tired of programming.
