An intuitive approach for understanding electricity
Vložit
- čas přidán 10. 05. 2024
- In this video, I try to explain electricity Ohm's Law… using a LOT of different demonstrations and analogies. I've been working on this script for like a year and a half now - this took SO long to assemble because electricity is an absolute pain to learn and to explain. I crammed every analogy to describe electricity I could think of into this video (which is why it's... oof... 40 minutes... who's going to watch this?).
When I learn something hard, it's normally after I've seen it a few times before, so with a tough topic in this video, I'm trying to scatter-shot and hope that at least one demo clicks for everybody! If it DOESN'T click for you, let me know what's weird! There will be an FAQ about this video posted on the second channel in a few weeks. If you want to ask a question, drop it in the comments here, or if you want to make sure I see it, leave a note on the new Patreon Discord server!
The biggest intentional omission in this video is not addressing radial charge distribution in a wire, and I know that's going to annoy some of the commenters here. I only talk about 1D wires so I don't have to confuse people by making them imagine different families of electrons at different parts of the wire when at the end of the day they can all get squished and move the same way - so please consider all of my diagrams with electrons getting "more concentrated" to be looking all the way through a wire, including the surfaces :)
Also: I'm starting a Patreon! / alphaphoenix
And a second channel! / @alphaphoenix2
Thanks to the VERY FIRST Channel Superfans from Patreon!
birdiesnbritts
John Sosa Trustham
Vladimir Shklovsky
Chapters:
00:00 Intro to Ohm's Law
04:18 Current
06:18 Resistance
08:30 Voltage
19:43 The water Channel Model
25:06 Power and Energy
31:32 Clarifications
Media Credits:
Heavenly Choir, Monty Python and the Holy Grail
I Dunno by grapes is licensed under a Creative Commons Attribution license (creativecommons.org/licenses/...) ccmixter.org/files/grapes/16626
Acid Jazz by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license. creativecommons.org/licenses/...
Move Ya by Max Surla/Media Right Productions is licensed under CZcams Music
Mountain by Text Me Records is licensed under CZcams Music
Vespers by Topher Mohr and Alex Elena is licensed under CZcams Music
Switched on Carcassi by Brian Bolger is licensed under CZcams Music
Way Out West by Chris Haugen is licensed under CZcams Music
Urgent Mission, Randall Monroe, XKCD xkcd.com/567/ - Věda a technologie
FAQs and corrections in this comment!
Also: I'm starting a Patreon! patreon.com/AlphaPhoenix
And a second channel! czcams.com/channels/3GrRPAydgBn42lab2izBlg.html
I'll answer some of the most common comment questions here, but in a few weeks, I'm going to post an actual post-video FAQ video on the second channel including questions from the comments here, and questions from supporters on Patreon!
1) Pre-emptive answer: The distance any given electron needs to move to "pool up" behind a resistor is miniscule, but you can't ignore it. It's tempting to say that the moment you connect a wire, electricity is a pure wave where the electrons don't move from their starting positions, but in reality they just BARELY move from their starting positions. Imagine a big long line of people, and all the people in the back of the line take one step forward - now the front of the line is crammed SLIGHTLY closer together on average - that's kinda what's going on. The scale of all of this is really weird, so demonstrations amplify it, then the demonstrations get questioned for amplifying it too much…
2) lots of people asking about inductance. In the case of the water trough model, the inertia of the flowing water is similar to inductance, and if you wanted to make the inductance larger, you could put a waterwheel with a large moment of inertia in the channel. It would be hard to spin up, and then it would be hard to spin down once you got it going.
3) lots of commenters have correctly pointed out that my “replace all the electrons” statement was too general. I am referring to all mobile electrons, which in a metal refers to one valence electron per atom. However all of these electrons, no matter where they live in the wire (in the middle or on the surface) chug along at the same drift velocity and eventually would be “replaced” if you had a way to mark them
4)
Are you doing well?
One thing that I saw in your water examples that isn't representative of electric current flows is standing waves on the surface. In a shallow water type of flow it is possible to have stationary surface standing wave patterns appear. These are unlike traditional standing waves in that the it is stationary in time. These are caused because the water flow can be close to the speed of surface wave propagation. So in some of your experiments, e.g. at 21:00 the surface is clearly not quite linear as your model would expect. These effect will not be seen in electric circuits because the electron flow velocity will always be much much slower than the wave propagation velocity.
don't leave us hanging on 4!
@AlphaPhoenixChannel Okay, I think I get it. You were right to fear a fire. The demo was using nichrome wire... of I guess about 22 gauge... and about 3 feet long ... so about 3 ohms in resistance. That was to provide a length dependent voltage drop? ... and passing 1 amp of current was so as to create a voltage drop that would clearly register on your multi-mete. Anyway... that's 3 watts of power being dissipated over a very small area... so the the nichrome wire's surface temperature would start to rise quickly. Thus, it is very reasonable to fear a fire, if done near combustible materials, for an extended time. Very good video!
Ok, Another pedantic point about your example with the build up of charge in the wire as shown in 18:52. This is a great illustration, but it is misleading. The charge within the wire always redistributes to balance out forces because the charges are mobile. The potential across a wire is actually caused by extra or less charge at the *surface* of the conductor. This is because the free electrons will move until they can't move (which is at the surface interface where there is an abrupt change in conductivity). Even when there is a flow of current in the wire, it is the surface charge distribution that reaches equilibrium with the electrons bouncing around in the wire. Inside of a homogeneous conductor the distribution of charge will be uniform. This is weird because the electric field around each electron can communicate information long distances. In this case of current flow through a resistive wire, the electrons in the wire are all interacting with each other through the electric field. In this way the electrons colliding with the lattice are in equilibrium with the surface charges which are actually developing the electric field in the conductor that equilibriates to balance the effects of the "collisions" with the lattice.
as an EE grad student, this is the first time the term "electron volt" has made sense to me, never got why mass/energy was expressed as that unit
Thinking about the energy of a photon E=hf, an LED with a 2V drop will emit a photon with an energy of 2eV (red). Because each photon only reacts with a single electron. The same intuition behind the photoelectric effect. From a perspective of linear electrostatic particle accelerators, it also made a lot of sense to talk about the energy of an accelerated particle as being a function of the voltage it was accelerated by and its charge. The use of eV in particle physics world is likely a holdover from those days.
I think you’re right it is probably based on accelerators. It’s super easy to express the energy you added to a particle in eV if you multiply the charge of the thing by the voltage across the plates in your gun! As particles started splitting and ending up with different masses AND energies, I think the potential necessary to slow any given particle to a stop may also have been relevant (although now don’t they look at orbit diameters in magnetic fields?) I need to know more particle physics…
@@AlphaPhoenixChannelafaik you are right. Cyclotrons and Synchrotrons make expressing electron (or proton) energies as eV VERY attractive. And since a Joule as the "default" SI unit of energy is HUGE compared to an eV it's basically useless in this regard...
The only thing I can't tell you why is "why didn't physicists invent an in-between energy scale when they discovered the first signs of the charm/strange quarks at many many MeV" but maybe they were just used to eV by then and so we continue to this day saying an electron is 511keV...
Edit: I just tried checking wether or not "natural units" might have something to do with holding onto the eV, but couldn't find my old lecture notes. So it might be a good starting point to look into c = h_bar = e = 1 which makes basically all physical units be eV as to why we still use it instead of some other slightly better positioned unit
yes, they flat out lie to use to try to 'make it easier ' to understand. Where a clear simple explanation could deliver the principals easily. Its like saying to someone: "its just because"
1 EV was taught us as equivalent to 1 Mosquito Power
I’m a professional electrical engineer with 30 years of experience and an adjunct physics teacher. I am Old. I think this is probably the best examples I have seen for examples of voltage and current flow. Excellent job and my hat is off to you.
I have a 4 year education in the field, I feel I understand it better after his video than after 4 years of high school haha
@@CharlieTheNerd91you probably did. Everyone equates a degree with understanding when in reality all it meant was that you could pass tests :P
Some of the most amazing teachers I’ve seen have been on CZcams. I just wish they’d get their act together and make a CZcams university.
@@stevrgrs Absolutely true. Those were four mostly wasted years of my life. We had two excellent teachers who were experts in their fields, and the rest were just people who could not get a job in the field, so they started teaching.
@@CharlieTheNerd91yeah I’m 43 and had a mentor that I learned everything from but back then society trashed everyone that didn’t have a degree or was a tradesman. I would tell people I wasn’t in school and they would look at me like I was a heroin addict.
Now I’m the one with the student loans and the tradesmen are retired and spend their days fishing and doing whatever they want 😂
I’m so glad my son will grow up with all this awesome information !
I found this video whilst trying to find someone that could explain electricity like I do so my seven year old doesn’t have to listen to me all the time :P
I have an engineering degree and I never quite understood electric flow until I stumbled upon on this gem of a presentation and I am pushing 50. Never too old to learn. Top notch.
As a 77 year old Amateur Radio enthusiast I am tired to the max of taking all my theory on "faith" only and not a working understanding of how it all works. Wish we had the benefit of CZcams 50 years ago. Thank you for taking the time to put this all together. God Bless...
A 71 year old Ham here. Hello and 73
You're gonna be really disappointed when you realize the theory is math based and then learn what an axiom is.
There are some really good old books for technical stuff regarding that I got some through thriftbooks I don't have access to them at the moment but I found them by looking up lists of recommended books
"HOLES AREN'T REAL!" 😂😂 I love that line.
K3TBA
"Height isn't a measure of energy."
As a hydraulic engineer I took that personally.
😏
Head is.
Blaise Pascal would have, too.
It’s like having a reservoir the size of the oceans and adding a cup of water at one side and having a cup spill out the other side thousands of kilometres away. The individual water molecules don’t move very far or fast, but it’s the influence that each molecule has on the next, ie a wave, is what is carrying the electric potential effect on the other side.
This is a bit of an epiphany for me. Thank you, Brian. 🥲
I’m glad! You’re welcome! I love this phrasing - that’s a great mental image. Still off by many orders of magnitude, but much more tangibly similar to the truth than the few-inch deep channel
@@AlphaPhoenixChannel GAH, the scale is mind boggling. But I'm closer to the conceptualization of electrical systems thanks to you 🙏 You're a leader.
This actually helped for me! Thanks!
Interesting. I made a similar analogy before I saw yours. Great minds!
@@AlphaPhoenixChannel so, a field perturbation of some kind?
P.S. I’ve always had trouble conceptualizing many of the fundamentals of electricity. Your video is breaking down those walls. Thank you!
I only started AC analysis this year
but i love how all our maths is just making everything work with ohms law
Haha yeah then it’s even weirder because you can use ohms law on an instant-by-instant basis to analyze real current, or you abstract an alternating current into imaginary numbers and somehow those still play nice and linearly with abstracted impedances. It’s amazing how many bizarre systems (even within electricity) can boil down to “thing is proportional to other thing” 😂
Don’t forget Euler’s formula, and the fact that such a thing is possible only because those circuits are linear time-invariant and only sinusoidal inputs are allowed and steady-state is assumed. It’s not just thanks to “Ohm’s law”.
I'm an electrical engineer and had till recently a very clear idea of "how electricity worked". Heck, I even wired all the electricity in my home. My understanding all started to shatter when Veritassium started talking about the Poynting vector 2 years -ish ago and *you* dear AlphaPhoenix did a follow-up video which I loved. So I'm more confused about the theory that explains why I can build such electronic marvels in the real world with no sweat 🙂 I guess that's the difference between a PhD and a Masters degree... Congrats on sustaining your thesis by the way. Never too late to celebrate.
If I've learned anything at this point it's that I don't really know anything.
i am unaware of this theory - " the theory that explains why I can build such electronic marvels in the real world with no sweat", this no sweat building theory, what is it called?
“The Final Theory: Rethinking Our Scientific Legacy “, Mark McCutcheon for proper physics. Electricity is expanding electrons crossing over from the subatomic realm to the atomic realm and spiraling ( the skin effect) around the wire physically; not E B ‘waves.’
@@doublewhopper67 Gravity is simple Galilean relative motion. The earth is approaching- expanding at 16.14 feet per second per second constant acceleration- the released object (apple). D=1/2at^2 major part of the Atomic Expansion Equation in referenced book.
Wtf@@davidrandell2224
You're able to convey information in a way that people don't just hear what you're saying but they understand it.
You use technical terms when appropriate and you also break down their meanings and give insight into what things really mean instead of leaving it behind a technically accepted definition of the word.
The point is, being able to teach things effectively and in a way that the majority understand is not a common trait.
I hope you continue to make more content and keep exercising this ability. Good teachers are hard to find.
Thank you for your kind words! I truly believe that effective teaching is a rare skill, and it's great to hear that the CZcamsr was able to convey complex information in an understandable way. As someone who values quality family time and outdoor adventures, I also appreciate products like the Segway Portable PowerStation Cube Series. Its massive capacity, fast recharging, and versatile sockets make it a reliable power backup solution for camping trips and ensuring uninterrupted family time. Keep up the good work, CZcamsr!
Thank you for being intelligent enough to teach without answering questions with an equation. Equations arent answers, they’re just tools that explain absolutely nothing about how or why. Thank you sir.
wrong.
My hat is off to you AlphaPhoenix because you've succeeded at completing a task that I've been trying (and failing) to do for over 40 years : i.e., Fully explaining Ohm's law and making it understandable to a layperson with no prerequisite EE knowledge in under one hour. You're the teaching hero my family needed! Many thanks to you for taking the time to make the video :)
I teach electricity and showed this to my students. About 30% of them understood it. The rest of them got lost about 10 minutes in. Think understanding electricity takes time and effort. Most people don’t understand it because they don’t want to put in the energy to learn it.
Learn the proper way. Rick Hartley on twisted wire pairs, transmission lines.
Electrons don't push each other.
The power from your home doesn't share electrons from the power station.
As a lifelong High Voltage Electrician I can tell all that this is absolutely the best presentation of what I've been telling folks my whole life. Great job! As I grew & developed my family and housing, my children learned physics beyond their years. Water + movement - Electricity = Work-Power
I love that! I hope to teach my children likewise someday. Understanding the basic physics of things is so satisfying when you can look at an object and think "I bet I could reverse engineer that." lol
The water model breaks down when you understand the transmission lines .. it's a terrible tool and that sets up the mind set that electrons push each other in a circuit and they don't.
@@Dazza_Doo Terrible is an exaggeration. AlphaPhoenix's demonstration even shows how water acts like a wave channeled through a waveguide. Opening the switch initiates a wavefront that travels along the channel until reaching a barrier with a new impedance, at which point it can partially reflect and partially transmit. The only thing unique to a transmission line is the electric field is a 3D vector field rather than the 1D scalar field of the water level, so you have added complexity with TE and TM propagation modes. But the root of wave propagation is the same for both water and electricity.
This a great tool for getting young minds to make analogies between things they can easily see and things that are basically invisible. Don't discredit simplicity just because it's not flawlessly accurate. Insisting on telling everyone how complex physics is dissuades many from ever attempting to pursue it. It's disheartening because, sure, some of the math is complicated and a grind to get through, but most of the physical concepts are very intuitive.
@cwithham69
Did you know there is an alternative cosmological theory called the Electric Universe?
The Thunderbolts Project and more recently Breaking the Science Barrier are Electric Universe yt channels.
@@Dazza_Dooelectrons do, in fact, push one another. Why else would there be any potential difference in a transmission line caused by a generator. Think of that for a second. The generator excites electrons near it. This excitation spreads through the electric field causing each electron to interact with its adjacent counterparts. However, this reaction isn’t instantaneous - as electrons have mass and absorb energy; therefore, the traveling wave in a transmission line is a product of a the ‘speed limit’ of the electric field. Furthermore, since electrons all possess the same charge characteristics, the fields all interact similar to a fluid. This interaction is repulsive in nature. The water model is not a great model - nonetheless. The gravity model is the best, but there is no parallel to negative charges for gravity, as antimatter’s existence is in question. The gravity model is similar because of gravitational fields and every objects linear contribution to the total given gravitational field at any point.
Am 45 and struggled for years to grasp voltage vs amps. This video finally made it all make sense. Thank you!!!
It can be confusing. Some people think a 12V battery with 800 cranking amps can kill, if you touch both poles, because of the high current.
But because skin has a high resistance, there is barely flowing any current if you touch both poles of a 12V battery.
Higher voltage on the other hand, forces more current through skin, but it's not the current we should worry about.
Example: Worst case you need about 1000000V before 800A can flow through skin (but it's not relevant!).
In short, it's the voltage that's dangerous.
Touching anything under 48V is unlikely to kill anyone.
But 110V for example, can surely kill you!
Edit: Some clarifications.
I'm 42 ATM and finally I can say the same :D
Now I’m down a rabbit hole with learning about high versus lower ohms, watts, wire ratings, etc. LOL
@@BrainHurricanesI learned very young at age 13 difference between voltage and amp...don't ask me how.😅
@@BrainHurricanesyou actually don’t have the concepts right. The battery supplies a voltage that is given by the electrochemical reaction used in the battery. It defines the potential difference (voltage) between the poles. There is no current associated with a battery. The current that will flow is given by Ohm’s law when a load is connected. That’s what you almost had right by referring to the resistance of a person’s body (“skin”); whatever the load R is, the current (I) will be given by I = V/R. V is fixed by the battery, but I depends on R. “Cranking amps” of a car battery, which you mentioned in your comment as if it were relevant, is only specifying the capacity of the battery (how large it is or more technically the capacity of the chemicals inside), which relates to how much current it can supply (quickly) for starting your car once the circuit is closed with a fairly low resistance of your starter. It doesn’t tell you anything about actual current that is somehow “supplies.” BTW- You can get quite injured by much less than 1 million volts, as you claim. Ask anyone who has accidentally grabbed two ends of 110V with their two hands. Current flowing across arms can stop a human heart almost instantly. I just want to make sure nobody reads your comment and thinks anything less than 1 millions volts is safe.
I cannot tell you how thankful I am for this. I always struggle when I can’t see ‘how’ and ‘why’ things work, and I had this issue in school where we learned to memorize things but were never explained why. It’s only as an adult that I’m relearning things for fun that i never fully grasped while supposed to be learning it
I'm exactly the same :). This is one of the few channels that really gets my attention which is why it's so good.
Omg same! If I don't understand something, maybe I can memorize it for the test (sorry, matrices; I tried) but no way is it staying in my brain!
+1
Wow, same for me. I've learned hundreds of times more, as an adult via videos like this, than I did at school. I just love knowledge now and didn't care much for it at younger ages
@@emilyrlnI suggest 3blue1brown's linear algebra list for REALLY learning how matrices work but to be proficient with them practice is necessary.
Wow, man, you are one of a kind.
Please dont stop doing these. Youre doing a big service to humans.
Thank you.
56 year old engineer here - ths is one of the best demos of Ohm's Law I have ever seen.
As an EE dropout that became a hobbyist and still loves this stuff... This video is fantastic! I'm gonna use it to explain the concepts to others. It's so intuitive!
thanks for mentioning XKCD's "urgent mission" and saving me the trouble of doing so myself. As an electrical engineer, this is one of my favorites. 😀
In a way Franklin did us a favor by getting the sign convention "wrong". He taught us that we have to be more flexible in our understanding of what "current" really is, and that it isn't necessarily electron flow, and also isn't necessarily in the direction charges are flowing. Had he gotten his sign convention "right", we'd learn from day 1, that current is the flow of electrons, and most people would complacently stay in the dark about other possibilities.
@@carultchI think electron drift has been solved for a long time. I’m trying to make a crookes CRT in the garage right now
Have struggled with the water model for years due to lack integration of particle physics and too much anthropomorphic metaphors. This has helped a ton. Thank you for working so hard on the visuals.
I don't know what sort of introduction you had, but water analogies are absolutely where electricity should be begin. They just need to be given with the caveat that water molecules don't push on each other at a distance, they have to bump into each other (at room temperatures) and water molecules don't have another field where changes in one field affects the other. So electricity will travel through a wire faster than water in a pipe because elections will push on each other despite large gaps between them, and water won't have things like inductors. But pressure is a high level thing, and at the level of pressure they are very similar. If you were transmitting power long range with pressured water in a pipe, would you want to use low PSI and require the water to fly through the pipe at super high speed, or a high PSI and let the water move slowly through the pipe while delivering the same power? Anyone who has ever blown water through a straw will know it doesn't like to move at high speed through the straw. Its why long range power lines are 200,000V and up. You might be able to plug a low PSI pipe with your finger even if the pipe has a 1 mile diameter and turns a generator that could vaporize you. A 12V submarine battery wont do anything to you if you put your hand across the terminals but it will vaporize a fork across the terminals. Low pressure but a potential Niagara Falls of volume. There are good analogies between "ground" and the ocean also.
As always, no matter how much you know about a subject this channel always finds a different way to make you visualize the concepts!!! I love your work man, it’s of extremely high quality! That model you used to describe the random movement of electrons is AMAZING.
I teach HS physics. This was one of the best explanations I’ve seen about the various electrical terms. Thank you! This is going to be a new video that I’ll have my students watch.
Minus one large technicality.
@@MRm3th3ad please elaborate.
Ok. I mean if your teaching it , you must imply to your students only for a reference to understanding, I also use examples to try explaining to folks in the 12volt community but , technically it's not right. Current doesn't flow through the conducter, it spirals around the outside of the conducter "wire" , nothing flows inside. So with implied examples, it kinda steers u in the wrong compression but it does help to understand resistance but then again that's not what's actually occurring.
That is so cool, you sound like a very dedicated teacher!
@@MRm3th3ad Your point is trivial and irrelevent.
Wow that tabletop demonstration of resistance with all of the videos overlayed is really cool 👍
That was my Aha! moment for sure.
Yeah that was super decent.
The funny thing is that I've played with electronics more than plumbing, so the water analogy tends to only help me understand how plumbing works more instead lol
OK, can you explain me how to create water pressure regulator? And is the simple water valve pressure or flow regulator?
@@ksrele A valve will act like a variable resistor.
If pressure is fixed you regulate flow, if the flow is fixed you regulate pressure.
In order to construct a regulator you would need to incorporate some reference as a setpoint and some sort of measurement for feedback.
I need to watch this every week just to keep it clear in my head. By far the best description I have ever seen. Thank you.
Repetition is the key to good learning, get it stuck in your head, like listening to a great song.
I agree Im 72 and dropped my first electronics class in Jr college because the teacher was former Stanford instructor and required his own book for his class. The first chapter I was totally lost he was talking hole theory chemistry and moles, Physics and electron valences. I just wanted to be a technician not a physics buff. It was like Taking us skiing down a Black Diamond hill. Before we knew how to snowplow. This video helped a lot But I'll have to watch a few more times. I dont get how electrons move from atom to atom at the speed of light. There has to be some minute fraction of a second where the atom changes from what it was. interesting that Voltage can make atoms and electrons more pressure and volume. Higher potential to flow. But what of high voltage low amps. I'll watch again :)
This is why you are one of the best content creators out there. You have a talent for explaining complex phenomena in ways that can be easily understood.
Software and math guy here...dabbling in electronics. This is hands down the best, most illustrative and intuitive explanation I've encountered. The visual representations you chose really upset my current mental model and set it correct. Thanks so much. This is fantastic!
His education will oversee surface mount technology by robots. Useless meta pseudo philosophy not real physics
How does the Water model explain Transmission lines?
It can't. Search Electro-dynamics for answers
Same. I'm going to watch this video at least 5 times. I finally (sort of) understand negative volts.
@@jonragnarsson hmm ... all elections are negative 😊 the positive gaps are materials lacking in electrons ... happy Christmas 🎄
Every time I start to think "Hmm, quite a bit of time since the last AlphaPhoenix upload" it only takes a few days and I see a new video from you!
May be I should think about that more often :D
I've been learning and teaching this topic for a long time, and always thoughts there must be a more intuitive/ accurate way of thinking about it than the traditional pipes and pump model. I've searched long and hard, never finding anything, so for me this video is genuinely wonderful.
As a high school electronics major, they never really taught us to think of electricity that way, mostly how to calculate things and that has been bugging me since I've started learning electronics. This video is awesome! Love all the analogies and various explanations. It feels like I actually have a grip on those supposed-to-be basic concepts now.
Just read the textbook ffs. It literally explains all this stuff, in better detail and with far more information density. You should be reading the chapter before you go to lecture, and never take notes, since it just distracts and wastes your time. This is coming from someone who got a 3.98 GPA doing a physics major at UC Berkeley (I got 2 A-'s).
Wtf Is high school major
@@chrissantos7865Advanced diploma?
@@pyropulseIXXIwhat an embarrassing comment lol. Save this one so you can read it again in a few years. Make a note that the OP was a high schooler
I don't know what sort of introduction you had, but water analogies are absolutely where electricity should be begin. They just need to be given with the caveat that water molecules don't push on each other at a distance, they have to bump into each other (at room temperatures) and water molecules don't have another field where changes in one field affects the other. So electricity will travel through a wire faster than water in a pipe because elections will push on each other despite large gaps between them, and water won't have things like inductors. But pressure is a high level thing, and at the level of pressure they are very similar. If you were transmitting power long range with pressured water in a pipe, would you want to use low PSI and require the water to fly through the pipe at super high speed, or a high PSI and let the water move slowly through the pipe while delivering the same power? Anyone who has ever blown water through a straw will know it doesn't like to move at high speed through the straw. Its why long range power lines are 200,000V and up. You might be able to plug a low PSI pipe with your finger even if the pipe has a 1 mile diameter and turns a generator that could vaporize you. A 12V submarine battery wont do anything to you if you put your hand across the terminals but it will vaporize a fork across the terminals. Low pressure but a potential Niagara Falls of volume. There are good analogies between "ground" and the ocean also.
Glad to know someone of your big brain understanding also struggled a lot with this concept. Although I'm familiar with the analogies you presented, I must say the way you presented them has cemented them a lot better - I do feel upgraded to having a VAGUEly decent understanding now.
Thanks SO MUCH for these kind of explanations! My head always did this in school and still does, I was terribly slow in doing homework because I couldn't learn formulae just like that, I had to understand them to reconstruct them at a test. haha But, though schools don't work like that, I think that's way better... understanding something makes learning easier instead of cramming formulae in your head.
This is some really heavy stuff that would normally be miles over my head, but you’ve found a way to explain it simply while not watering down the important points. Very well done my dude 👌
Dude you are a godsend, you literally explained how electricity works better than any teacher or any learning material I've ever tried to learn from. Good stuff, thank you.
This is my favorite video on youtube. For YEARS I have tried to imagine how electricity actually works (using analogies). After a lot of headache, this just confirms what I was thinking AND taught me why the wire connecting to the terminals of a heating element don't also heat up (a question I've been having for a while now). Simply the best researched.
My guess for the nanosecond scale voltage-wire slice-time graph is - based on your previous videos - you might have used your oscilloscope to measure at a certain point on the wire and the input, moved the probe to another point, repeated the experiment, exported these snapshots and used some python wizardy to match them up and transform them (time vs voltage at a specific point on wire) to get the 3D graph (point on wire vs voltage vs time). Also, I think this is the best explanation and visual experiment for getting a grasp of these concepts, while also keeping it focused but still telling the small print later on, it should be played in schools. Thanks!
Ok, I’ve two things to say here.
1) Very good job outlining the intuitive approach to learning about electricity and how it works. I literally become a bit smarter (about this) after watching your video.
2) Your enthusiasm helped me want to learn more because it’s how I teach (automotive and criminology). So many presenters on this site merely go over formulas and surface-level material so dryly that I wonder if they’re even interested in their own lectures or explanations. The water table made things so much more understandable because I struggled with the notion of ‘potential’ regarding voltage and the water analogy made so much more sense.
Thank you!
So true, if the teacher is bored students can tell, they immediately think well if he’s not interested why should I be? The problem is if you ARE interested and desperately want to learn, it can be incredibly frustrating. I’d rather have an average teacher who cares, than some know-all who’d rather be doing something else.
Thank you so much! as a mechanic who has been in the field for 5 years this is the first time anything about ohms law made sense in my head, I finally have a confident understanding!
I have never studied and hardly understand anything about mathematics in this field. But I want to thank you that even I am able to understand these things through your visual experiments, at least superficially. I wish I had had a teacher like you earlier. Probably then I had studied before :)
Thank you very much for this!
Well you are studying right now. I think the hardest part about learning/studying is to find the right starting level. If there is something the teacher assumes that you know, but you don't, it can make it really difficult to realise that assumption by yourself, and it can make learning really hard. On the other hand if the teacher assumes you do not already know a lot of things, that can make learning very boring. If you are one on one with a teacher you trust, you can tell them that there is something you do not understand, or that you do understand the part they are descripting thereby you can move along. But on the other hand, if you have a book/video you can go back if you find something that you thought was less important but turned out to be very important, you can take a brake when you get tired, you can jump ahead if you are bored and other things that can be harder to do with a teacher.
But there is no doubt that a good inspiring teacher can change your life and send you down a path that you would never have ended up on without that teacher.
Understanding something start with understanding it superficial and don't let math hold you back. If math seems hard it i probably just because your are missing some peach of the puzzle (an assumption) or do not understand the syntax. Practice notering when there is a key peace if information holding you back, and how to find that peach. Do not let anyone, not even your self hold you back if there is something you would like to understand, and over timer you will see how many pieces of the puzzle that are reuse again and again and often you can get a good 20% understanding of something new without that much work. But also know that you will never be able to learn everything about anything, and that the more you learn the more you will know that you do not know. Learning can be very humbling, and most of the time we are only learning half truths, the har part it to know when a half truth is useful and when it is not. Keep it up.
Jesus Christ... next time you chatgbt it at least give some parameters to add paragraphs 😂
Makes it hard to study otherwise ✌️
@@cwarky7325 hehe... Just get good noob 🤣
The key new intuition I actually gained from this was understanding why and how resistors convert electrical energy to heat, rather than simply understanding that they do
Seems pretty obvious it is due to collisions; this is stuff you can easily deduce as a 13 year old by just knowing that things are made of atoms and particles
I really feel blessed to have found this post. I am in awe of the intensity of enthusiasm which you display !
Thank you
You're the best kind of nerd. Genuine enthusiasm and excitement is apparent. Thanks for helping me make sense of this crazy information.
I did have a bit of a chuckle at seeing the vacuum permittivity constant described as "some useless constant"
I had also assumed that your electricity waves we're going to be based on solving Maxwell's Equations... Now I'm really looking forward to seeing how you went about actually measuring that!
incredible video thank you, i find this water channel model quite a lot more intuitive than the usual water in a pipe model we get shown in schools.
this plus your "Path of Least Resistance" video have really furthered my understanding of electricity
I'm a computer engineer. Took a lot of Electrical Engineering course, of course, and in my Electromagnetics and Optics course (Physics 261 at Purdue), I scored 399/400 (all in exams, as that prof didn't give credit for homework).
AND I THINK THIS VIDEO IS GREAT because it still taught me stuff and provided me new ways of looking at problems.
This is AMAZING! I've been searching for YEARS looking for an intuitive explanation for voltage and Ohm's law and why it works the way it does. The water pressure thing never really quite made sense to me (since I felt like it broke down when you thought about it hard enough), but comparing voltage to water *height* instead of *pressure* suddenly made everything work. I love that explanation! This was a fantastic video to watch.
As a layman, I loved this video - it really does provide a level of intuition that I didn't get from previous explanations/analogies.
One thing not addressed is why, when there's no resistor in the circuit, the voltage drops linearly along the wire. If I had to guess, it's because the wire itself is actually infinitely many small uniform resistors in series, with infinitely many small sections where the water level is "flat". Kind of like how calculus derivatives are explained - from discrete segments of dy/dx to a smooth tangent curve (as dx approaches 0). And why does the linear drop go away when a resistor is added? Because the resistance of (any section of) the wire is now insignificant, compared to the resistance of the proper resistor. So each of the two "flat" pools of water on either side of the resistor is actually a linear drop, but with such a small height difference so as to appear flat.
Your guess is correct!
Correct. When he showed the smooth drop in voltage over the wire vs. the step when the resistor was added, he did both tests at 1 volt, which means much less current was flowing when the resistor was added. In the water trough analogy, say that when he showed the smooth gradient with no stoppers it dropped 2 cm. To make that drop, he was flowing a large amount of water and it was flowing very fast and at a uniform speed across the length of the trough. When a stopper was added, if he wanted it to still drop 2 cm over the entire distance, he had to pump much less water through the trough because it is now flowing the distance much slower on average. It is moving very slow on its way towards the stopper, so it has time to come closer to equilibrium before it reaches the stopper. It then goes past the stopper very quickly as it loses all of its "voltage" in a short distance, then moves slowly again to the exit so it comes close to equilibrium on the other side. More stoppers means the water moves slower on average and he needs less of it. This is a constant voltage power supply.
On the other hand, if he wants to keep the amount of water the same and puts in a stopper anyway, the height that the water falls at the step down of the stopper will be much higher than the original height that it dropped across the distance with no stoppers. It will still be slower than before on either side of the stopper so it will form a step, but will move much faster in the short distance passing the stopper, which will keep the average speed/amount of the water the same as it was with no resistance/stoppers. This is a constant current power supply.
Summary: For any given voltage (overall drop in height of the water over the distance of the trough), adding a resistor (stopper) will make the current drop (require less/slower moving water) and the voltage will therefore have more time to equalize on either side of the resistor. You can actually see as he moves the stoppers up (decreasing the resistance) that the water on either side starts to slope more and when he moves it down (increases resistance), it becomes more and more of a defined step. It is not the presence of just any resistor that makes the step; as the resistance value goes to 0, the voltage (water level) on either side will start to angle more and more and the curve will approach that of the original curve with no resistor. As the resistance gets higher, the curve will become more of a definitive step with the voltage on either side being more and more flat.
@@phillipthompson2347damn you’re good at this…
@@phillipthompson2347 hey in your first paragraph, why does water move slower when going towards the stopper? And why can you use the water analogy more when you said that water loses energy after it passes the stopper? And that it moves faster there.. I would really appreciate you if ya help me understand. By the way, what’s the relation of water molecules speed and curvature as it drops down across the distance
The analogy of playing with waves on a very deep ocean and the size needed of the trough to represent a 1 volt drop just blew my mind and makes an infinite amount of sense to me.
It really demonstrates how powerful the electric force is, that even such a small, imperceptible change in the total can have such a remarkable effect in things like railguns and high explosives. Imagine if you could access the depths of that abyss.
@@DFPercush Boggles the mind. Imagine having the motive potential of every electron available to you. Not just what comes out one end of a conductor.
Holy cow, that was in INTENSLY good video. As an engineer, I watch a lot of these type videos and this one REALLY stood out. I am so much smarter for having watched this , I cant thank you enough. Just really really good stuff.
absolutely brilliant, - after 4 years of materials science school and 2 years as a materials scientist, this concept has never made so much sense to me! Love this channel!
"Why electrons follow Ohm's Law"? Respect for authority!
Your enthusiasm and desire to explain reality in a way that makes it all make sense, is both engaging and incredibly beneficial for those with a desire to understand the matter you present fully. Absolutely an alpha channel.
Hands down the BEST and most complete video I have seen on OHMs law, I love your examples, the infrared cameras and analogies used! If my school would have had a teacher like you 35 years ago I might have become an electrician :). Thanks for creating this content!
What a great explanation! I've learned Ohm's law back in the 80th but never digged into it this deep. This was a clear, intuitive, eye-opener! 👏👏
I absolutely love your teaching style. I had a fair grasp of what voltage is before watching and have come away feeling I now have a solid grasp of what actually happens.
"All models are wrong, Some are useful, Very few are Magical"
This has to be THE BEST explanation of how ohm's law works that I've ever seen. I generally have trouble understanding abstract concepts. So to see it in physical form and explained this way was awesome!! Thank you so much!! I am now excited about electricity again and it's applications! I've had basic electronics 101 training back in the 1990's and have used it on my job as a Multi-craft Technician. But my understanding of the concepts were, this is how it works and that's it!
I am a person that needs to know why, things work the way they do to fully understand it! This teaching accomplishes that!
Brilliant. Thank you. I'm tasked with giving a workshop on "renewable energy" to a group of 4th graders. I have built a bike generator to help convey the mystery of "electric power." Your skillful blend of physics and intuitive experiential emersion will help me convey these invisible concepts.
The live graph at 30:49 might be the coolest representation in electronics that I've seen. What a great thing to show at the end of the explanation. That super worked for me! ❤
This video is incredibly taught and gave me so much insight on what I'm actually doing when working with electricity. Thank you so so much for this
One of the best Analogy I heard was a spring ontop of a mountain for Voltage. The height is the voltage, the narrowness of the channel down the mountain is analogous to resistance and the speed of water is the amperage.
Only watched half of this so far and already I have a better grasp than any electronics course I've taken. I'm a chemistry major and that part of my brain constantly tries to tear apart any analogy I've ever about electricity as being water through a garden hose.
So thank you!
Yeah I studied Chemical Engineering at Uni and I’m a wiz at Chemistry but I really struggled with electronics. It’s just not intuitive to me, or wasn’t, but I stuck at it. CZcams didn’t exist at the time but videos like this would’ve really helped me. Chemistry is awesome and I love it so much, what can do with just neutrons, protons and electrons and a few simple rules is fascinating. I call it Universe Lego. Anyway best of luck in your studies, hope you kill it.😊
You’re an amazing teacher. Love the way you explain and show all this. Most teachers can’t teach to make the information stick and make it fun. You can! Thank you!
The Terry Gilliam inspired trumpets for Ohm is perfect. Nice touch there.
You can also think of voltage as pushing a beach ball under water and once you let go the buoyancy inherent in the system requires the ball to rise to the surface with some amount of force which = ma not really of the ball which contributes a very small fraction but the water around it and the air pressure above the water forcing the ball to come to rest on the surface. Therefore voltage is not a force in and of itself but a certainty that energy will be transformed from one form to another. In the case of the ball, the buoyancy potential is transformed into kinetic energy until it comes to rest. The same is true of voltage which will remain until whatever is causing the voltage stops causing it and bam, through current and resistance over a very short time, equilibrium is reached just like a ball full of air floating on water.
The real big difference in the analogy is that the ball will try to float no matter what assuming you're on earth at sea level. Electricity needs a medium to conduct the energy transformation in. It needs not just any electrons but movable electrons around it to transform the potential into what ultimately becomes kinetic energy. That's why conductive materials conduct the transformation of energy from a voltage potential into a current which moves and encounters resistance through that conductive medium. That's also why a battery can store that voltage potential if there is no medium or conductor available for it to get out (mostly, batteries always leak a tiny bit all the time).
And then there's another thing to add. Even if there is a conductor attached to the battery, unless it's connected as a circuit, there's nowhere for that potential to go so it saturates what is connected and that too becomes part of the battery leaking a tiny bit as well over time. It's when you complete the circuit that the voltage can be relieved and the electrons truly flow according to the potential (voltage) contained within the battery generally by chemical means. A battery is literally like pushing a beach ball under water and then trapping it. Connecting the battery to a circuit (with a load which is important) is like removing the lid of the trap. As the ball rises to the surface kinetic energy (current) is gained like in the current created from a battery but once the ball is floating on the surface, that's the same as saying the battery is dead. There is no potential left.
Maybe Voltage could be better explained by the tendency and amount of it for a system to try to reach equilibrium. I mean, it's just a long way of saying potential. The more a system wants to reach equilibrium, the higher the Voltage. You're flipping right. It's really piss complicated to describe or understand with common objects and ideas.
I actually think current is weirder. It's not electrons flowing so much as it is the potential (voltage) seeking its way to equilibrium down the wire that is moving. The electrons themselves hardly move at all even though they are moving randomly at stupendous speeds. They do actually move through the circuit but they only move a teensy tiny fraction of the speed that the current moves as a quite literal wave. Water molecules don't move very far but the waves themselves move really far and the energy isn't in the molecules themselves. It's the wave of interactions that carries the energy from one place to another losing a tiny fraction of that total energy every step of the way in the form of heat which is another word for atoms and molecules jiggling around.
That's also whey people call the end of the universe the heat death of the universe. It's when there are no more waves left and that everything is in equilibrium. There is still energy there but since everything is in equilibrium there's nothing to change anything else. Everything is simply a soup of latent energy which unless we come up with some new physics is the ultimate end of all things uncountable years in the future. A pure equilibrium.
I appreciated how you made a bridge from this video to an analogy that more closely aligns with reality. Electrons are not flowing, they are “waving”. And your description of heat death as energy without potential connected the micro to the macro.
Hands down the best description I've ever come across. Thanks for your work
Been watching your videos for a while, and your water model has been one of the best analogy I have ever seen.
Thank you. Welcome back.
This is amazing, thank you so much, I've slowly been teaching myself this after decades of being interested in electronics, and only recently have I really started to understand what's going on. This really cleared things up in my mind.
It'd be awesome if you followed on with the "Holes" and went into semiconductors.
While I kinda understand how transistors work, it'd be nice to have some of your smart analogies to explain it better, especially with things like mosfets which still confuse me quite a bit.
Semi conductors are dielectric materials (like silicon) doped with conductors p or n (phosphorus, gallium etc..) when a threshold of current is met the gate/drain switches open and supposedly the electrons "skip" across "holes" (i don't believe in electrons) but I won't confuse you on that point.
The easiest way to think about it is that it is intermediate composite material between insulators and conductors placed between conductives like a little draw bridges that opens for current switch junctions or flow direction when electrostatic conditions are met.
If they “don’t believe in electrons”, don’t let them confuse YOU…😂
In semiconductors, as in metals, most of the electrons are locked in place because they are used in bonding. The difference is in metals, electrons can start moving down a wire if they gain just a TINY bit of energy - energy they can get just by the material being warm. In semiconductors, any given electron would need to gain a LOT of energy before it could start to flow, so the vast majority of them don’t - they’re stuck.
You can insert trace impurities of other atoms called dopants that basically add electrons that already have a bit more energy, that way again they only need a little bit to start moving like in a metal. By fiddling with the concentration of these dopants, and by applying electric fields across the entire material, you can create a device that sometimes has no mobile electrons so it’s an insulator, and sometimes has many mobile electrons and acts like a conductor.
All insulators could really be referred to as “high bandgap semiconductors”. There are even people trying to make electronics out of diamond, which is an extreme insulator.
You are an OUTSTANDING educator. Thank you!
This video goes right into my playlist "The best videos of the entire CZcams". So many questions that I've been wondering over from day to day at my job as an electician is awesomely explained.
Nice job on the video. Your demonstrations helped clear up some confusion I had about voltage.
I am a 83 year old electronic hobby student playing at it during the 1960's. Getting married and making a living in Architecture I have been retired for some time got involved with radio control systems for model aircraft and now trying to catch up with the micro chip age to keep
my brain alive. Thank you for the video .
These videos are the best I've ever seen explaining how this stuff works. My understanding (I've taught this stuff a bunch of times, not sure how effectively) of something as simple as ohm's law has been taken up a level with this video. I never thought as deeply as you have.
Decades ago when I worked as a carpenter and messed up some siding cuts on some rather expensive redwood vertical siding, a more experienced fellow told me to "think like a drop of water" That explained everything.
You are doing the same thing for electrons. Great work!
Ive been excited for this series of videos since you were talking about making your "water analogue video" way back. I love this model so much and I'm so happy you are talking about the fields and waves and velocity and all that. Great job man!
That's an interesting analogy for electron flow, indeed very intuitive, better than the traditional hydraulic analogy used in many electronic/electricity fundamentals courses (mine introductory chapters in class included).
One thing you mentioned that helps it is that the model is slow enough so you can see thing happening, and showed an actual transient and wave behavior; I was wondering if you could also show sinusoidal steady state (ac) in the model also, by making the pump somehow oscillate sinusoidally the height/pressure. Your model would probably show some inductance analog (since water has inertia) and capacitance analog (I think inertia also plays a role as such, but in the y direction); if you make the pump frequency (source) high enough (I would guess, wavelength in the order of magnitude of the size of the features of the model), I would bet you'd get some interesting transmission line effects in the model such as reflection, Ferranti, half wavelength lines, termination, impedance matching, etc
Electronics tech for 40 years, best explanation I've ever seen. Awesome video!
This was probably the best explanation, to the question of how electricity works that I've heard. Finally understood it.
Not that I'd be able to repeat it to anyone, but I at least understood it.
A lot of people get confused about the difference between voltage and current. I remember at school the thing that helped me separate them was when my friend said " Current flows. Voltage just 'is'. "
Voltage is dielectric capacitance stored or potential energy
@@off6848voltage is not potential energy. Voltage is electric potential.
Voltage is the potential function (from calculus) of the electric field. This means if you take the gradient of the voltage, you get the electric field.
I think it's really fun to imagine the electron-as-hill-of-potential. So you have your electron, and you have to push it up a hill to get it close to the other electron. But the electron itself is a hill, so you end up pushing a hill up another hill, which is hilarious to me.
That actually is the missing intuition I needed to understand why the energy is stored in the electric field, thank you so much!!! Also, I agree that it’s very funny lol.
would the coiling of a spring be a better analogy then? like two springs pushing against each other and storing energy as they do so?
8:49 "Voltage is weird." I don't know how many videos/things I've read to try and understand voltage and you're the first to put it in these terms. Thank you. Great explanations.
Haven’t yet finished watching (as it takes me a couple of rewatches per concept), but it’s already clear to me that you’ve made brilliant job understanding it yourself and explaining it to us. I was searching for this “deep intuition” for a very long time and now I’ll stick here for a while. Sincere gratitude and respect, sir. Please, keep making these videos
I wish i had this video when i was learning about this stuff. Probably the best explanation i have seen!
I thought I understood volts
W O W ! . . . i am a physics teacher with more than 18 years of experience and have been using the water model, but never at this detail . . .! My mind is stretched . . . !!! Superb . . .
Nice job! I’ve been working with electricity all my adult life. Electrical maintenance, electrical engineering and substation work. This video was informative. You know your stuff! Thanks!
The ball and hill analogy nearly caused me an epiphanic seizure. Something in my head clicked so hard, I almost blacked out.
I'm being facetious, of course, but you literally unlocked 1 component of like 50 things I've been studying, and all of them fell into place in that instance.
This would be an amazing video!😊
God I love this channel. You present things at a level that is neither condescending nor too technical. There are so many super intro level videos out there and then super advanced level shit and nothing in between. You bring advanced insight to these concepts I "knew" but never understood this intuitively! Keep it up man!
This kid just answered so many questions I have had about electricity. Not a grad student or anything, just someone who loves to play with and learn about electricity. I have struggled with the concept of voltage for years, and he made it finally make sense to me. Well done kid, you are extremely sharp. I will be happy to subscribe. Can't wait to learn more.
They don't "follow Ohm's law" They reliably behave in a manner described by Ohm's law.
Ohm's empirical equation is NOT a real Law. It is not fundamental (nothing has to follow it) and you should not pay so much attention to it. It's just a useful tool (but there are limitations), nothing more.
You have runners on a track, the first runners are fast nothing block them, the last take more time to finish, the resistor is an obstacle to the runners, so everyone runs to the resistor and then must pass it while being bunched up. Very cool video :)
This is the most intuitive visualization for ohms law and voltage I've come across. Well done!
This is great!!! Your demonstration creates a valuable mental picture and gives understanding
A fantastic description of electricity with simply models. Thanks for making this!
You helped me understand in minutes what i’ve read and studied for years. Thank you this has changed my view on electricity
Not only was this explained so well, it's engaging! It's one of those rare moments when you start watching something educational and you don't want to stop because you don't feel like you're being taught a lesson, this is learning.
If education would stop focusing on learning how to solve equations but rather how to apply an equation as a solution to a problem. People would be more success remembering or becoming interested.
Your graph at the end did it for me. Once I saw the measurement, it all made sense. My intuition "Believed you".
Excellent visuals and explanation. 75 year old EE. If only we had professors with your talent instead of those that read from a book to the class!
Your enthusiasm is just so. Friggen. Captivating. It's like the knowledge connects to my brain, making me understand your enthusiasm, which makes the connection stronger and repeats until the "path of least resistance" is cleared and it all just flows so smoothly. I'm excited as HELL for the next one!
Yeah, when a teacher is enthusiastic you instinctively want to join the party. He’s excited, maybe I should be too!
OMG this is the BEST explanation I have ever heard. I am an Electrical Engineer grad. Really amazing
thank you, you are talented to explain difficult things using simple examples
you would think in the ocean of information available today there would be similar high quality explanations available, but for me it's the first time I encounter such a thorough explanation with the intent of making it simple to understand