How does electricity find the "Path of Least Resistance"?

Ever wonder how electrons know where they are going? Electricity is a pretty mystifying topic, because electricity seems to be able to do impossible things, or at least things that don't make sense at a normal "human" scale. In this video I use a thermal camera to show electric current through a maze made of aluminum foil. The electric current very efficiently solves the maze, which is awesome, and heats up the "solution" so we can see it!
To explain this effect, I printed out the same maze but made of plastic trenches and not metal foil. By running water through this plastic maze, we can learn something about how electrons flow in metals. This analogy does have some limitations that you need to keep in mind, but for the vast majority of cases, I think it does a FANTASTIC job at modeling bulk electron behavior in "1D" wires.
At the end of the video, I have a few more mazes that have two solutions each, to test the "path of least resistance" adage.
Videos referenced:
"Can water solve a maze? - Steve Mould
• Can water solve a maze?
"Why Rivers Move" - Practical Engineering
• Why Rivers Move
Also relevant:
Discussion of current reflections from resistive loads @ 10:38 in this video from Electroboom and Veritasium
• How Right IS Veritasiu...
Music in this video:
I Dunno by grapes is licensed under a Creative Commons Attribution license (creativecommons.org/licenses/...) ccmixter.org/files/grapes/16626
Ether by Silent Partner
KZbin Music License

[@AlphaPhoenixChannel]

FAQs and corrections: 1) Someone very correctly pointed out that my final question with the "cutting the line" test was ambiguous. For all of these tests I had the power supply set up as a current source, not a voltage source. If I had been holding a constant voltage at the start and end of the maze (also assuming I would have had thicker wires) the result would have been different =) 2) Multiple commenters have pointed out that the classic “hydraulic analogy” deals with water PRESSURE, not height. This means that we aren’t relying on gravity, so very small changes in pressure can have very large current flows and power transmission, but I think it’s less visual than height and I wanted a visual representation. Also, the pressure at the BOTTOM of the channel actually is higher when there’s more water above it, so it’s almost the same! 2b) I want to take this opportunity to mention the “surface charge” thing. Yes, real charge carriers in a wire spread out the excess charge (positive or negative) by placing excess electrons or depleting electrons, exclusively from the surface (but this only-at-the-surface thing only holds once the system is in steady state). The equivalent here with water is like imagining the water in the bottom of the channel is always present, that’s like the electrons in the bulk of the wire. The “wedge” of water you place on top of it is like the “surface charge”. It’s physically in a different place, and you aren’t actually changing the amount of water in the BOTTOM of the maze, but the wedge drives the slow of water all through the channel. I normally don’t even think about the surface charge because I visualize wires as 1D objects. 3) upon further inspection, I misread my meter when I was looking at the “tall step”. It didn’t read 5 mV, it read 0.5 mV. I think the circuit shorted out somewhere in the lower left just before I made these readings, which would explain why the 70-something number was too low and why the 0.5 number was WAY too low. 4) “The maze should start half full” - you’re right! In electricity, there is a significant driving force to move charge around if a wire has too many OR too few electrons. Wires like to be neutral, and where negative electrons can move, if they abandon the material they leave it with a net positive charge cause the (positive) atomic nuclei have nothing to cancel them out! In the water model you can think of this as actively pulling water from one end of the maze AND actively pushing water into the other end of the maze. But in water, you have to rely on it finding a steady state to flatten out because any stable water level can exist - in electricity it kinda already knows what it wants. 5) A lot of people have likened this to lightning, and lightning is way cool. Unfortunately I don’t claim to understand exactly how lightning “chooses a path”, but it’s more complicated than this. I know it tries many paths at once, but because it has to ionize channels of air do do so, it forms a filamentary structure instead of the more “continuum” flow/wave thing we see in a solid brick of metal. 6) Many commenters have said that I just have an RLC circuit bouncing around. The thin bits of foil behave like capacitors and store some electrons using electric fields, and the magnetic fields around the input wires are coupling to this and making it bounce. YES! This is exactly correct, you’ve just used the more technical wording. I was trying to keep it very linked to the water model so I said electrons were “sloshing”, but that’s exactly what happens in an electronic oscillator. It’s like one of those wave pools hitting resonance! 7) I’ve had a few comments ask what quantum physics has to do with this, and I would say for this experiment, nearly nothing. The reason electrons can flow in metals has a strong foundation in quantum, but it all ends up isotopic so it’s very possible to handle electron flow as a continuum thing. The problem with seeing quantum effects in wires is that electrons like to run into things, and every time they do, they kinda rerandomize. This means that to see quantum effects you need something REDICULOUSLY clean like an ultra pure GaAs/AlGaAs heterojunction with a 2DEG, or your circuit features need to be ridiculously small. A few years ago I had most of an experiment set up to fabricate a wire one atom thick but didn’t have time and tore it down. I’ll absolutely be setting that back up eventually. 8) Local forces - the water molecules can ONLY interact with (and sort of exchange information with) their adjacent molecules, but that’s plenty for them to solve a maze like this. Each individual water molecule doesn’t even know that it’s IN a maze, but the collective is able to solve it - I think that’s really beautiful. Electricity on the other hand, DOES have some longer range forces, and this was demonstrated very well by the Veritassium experiment I set up for real in the field. The thing is, all of these long-range forces can’t actually DELIVER electrons - nothing’s moving down a wire, which means that the results from these forces are always temporary, and if you want a DC current to flow, that’s still set up by relatively local forces between nearby electrons behaving like water. 9) a LOT of comments are recommending slomo guys. A 10million FPS camera would take a frame every 100ns. That would skip right over the larger sloshing/ripples that I said were way too slow. Electricity is mind-bogglingly fast!

[@OrigamiMarie]

Not a mess-up, but a simple consumer-grade Cricut machine will cut your foil maze out very easily and with little danger 😃

[@Mezzo_Roo]

@@OrigamiMarie yeah but that wouldn't have been as cool haha

[@OrigamiMarie]

@@Mezzo_Roo true!

[@dougfoster445]

is it kirchoffs current law? States current remains the same at all points of a series circuit? Just taking a stab.

[@gingermany6223]

If you used a properly doped semiconductor, would it be possible to create a maze where the electrons flowed preferentially through one path but holes through a different path?

[@alext8828]

They take all paths. The less resistance, the more current flows thru that path.

[@Ethan-ej6fz]

In the case of a maze that wouldn’t be true. All paths that don’t lead to the exit would be considered as open circuits, and no current would flow.

[@smoothbraindetainer]

@@Ethan-ej6fz Yes they do. Just in that case, the resistance is such a high number the current is effectively zero. There's no such thing as an insulator.

[@movitoviscyrinxed446]

@@Ethan-ej6fz There is current flow when you introduce a new voltage to an open circuit. It's like when you charge a capacitor, there is current flow until it "fills up" on voltage and then the current effectively stops.

[@alext8828]

@@Ethan-ej6fz When I said "Path", I meant successful paths of varying complexity. I did not mean interrupted paths. A path, to me, goes from source to destination. But I see your point.

[@RupertBruce]

You might say that the field includes all paths. The current follows the path of least resistance through the field so electrons are more likely to appear on that path.

[@praetorprime]

Never thought I'd see a voltage divider in maze form. Incredible.

[@AlphaPhoenixChannel]

I was watching Steve’s video and at first I wanted to do the vacuum test, but then thought about it some more and the whole “built up pressure in the closed off bits” thing reminded me SO much of electricity I had to do it! I was thinking about this on a Friday while driving away to an FRC competition but you better believe that on Monday night after I got back I was in the garage cutting foil 😁

[@monad_tcp]

How do we create a depletion zone with water? I mean, is it possible to have a transistor for water?

[@benniethejew]

​@@monad_tcp kzbin.info/www/bejne/hqW7mJitr7lkfNE

[@yearswriter]

@@d.6325 Actually, I think Steve Mold even had simple water-based adder for couple of bits

[@maxgood42]

@@d.6325 Yeah I guess this is what you may call an Abacus with extreme mechanical princebles at play, I think the very First calculator ever made was the size of a small car?

[@ElectroBOOM]

Awesome experiment!

[@gallium-gonzollium]

Imagine all of these youtubers collaborated together to make the best video ever.

[@Metal_Master_YT]

@@gallium-gonzollium ok, now I need that.

[@AMATISIG]

Just don't short it !!

[@baptistebauer99]

@@gallium-gonzollium Melting lipstick...? (IM KIDDING)

[@tyrannicpuppy]

@@gallium-gonzollium They set up the coolest circuit ever. Linus accidentally drops something and somehow Mehdi is still the one that gets shocked.

[@Uthael_Kileanea]

For me, as an engineer, watching this video is like relaxing in a forest near a lake in springtime. Thank you for this effort.

[@margodphd]

Same, which is why nobody outside of scientific community wants to hang out with me 😢😂

[@wayneyadams]

Using thermal imaging to trace the current is a really great idea. I taught Physics for 33 years before retiring 7 years ago, and I wish I had thought of this demonstration. I really did not see any errors in your explanation, good work.

[@Operational117]

You can suggest it to every physics teacher you meet. Just because you can't teach with this method any longer doesn't mean you cannot suggest this to other physics teachers. Spreading knowledge to other teachers is just as important as spreading it to the students.

[@graealex]

Or just crank up the current until the thermal radiation decides to enter the visible spectrum 😅

[@wayneyadams]

@@Operational117 I would except that I have not been in touch with any teacher since i retired.

[@X4Alpha4X]

Thermal imaging is also an incredible way to help diagnose bad circuit boards. If you look at a powered board under thermal and see one extremely bright spot, you've almost certainly just found where an IC unit shorted out.

[@ska042]

​@@graealex That's actually a fun idea, just increase the current until it starts glowing a bit. I'd imagine aluminum foil probably has a very narrow area between "glows a bit" and "melted" though because it's so thin. Alternative idea that comes to mind: Put the foil down flat on a piece of thermal printer paper (the stuff used for receipt printers), just hold it down with a wood or acrylic plate. It'll take a little tweaking to get the "exposure" right but there should be a combination of current and on-time that darkens the paper juuust right so you can see the pattern on the paper after you take off the foil.

[@aaronlow1977]

It's very nice seeing so many Physics KZbinrs duplicating experiments using different methods, but getting similar results. My understanding of these different concepts is increasing because of this. Well done. I especially like the 1 light second power transfer experiments by you and many others.

[@djosearth3618]

thhx now i know what to look for next! appreciate that 1 C sec tip

[@PinkeySuavo]

yeah learning the same thing from different sources is the best thing to do I think. There's always someone missed or someone added extra and you can get some average of all you learned

[@rajonstephano9857]

I'm currently a PhD student and about to publish a paper discussing spatial dependence of microscopic percolation conductance. We are studying the case of a conductive 2D lattice (essentially a maze), and although we use computer simulations to do thousands of runs (since we are interested in the average conductance) this video was still very illuminating. Thank you so much :)

[@AlphaPhoenixChannel]

Sounds fascinating! I always liked the percolation problem.

[@rodsmade]

sorry to say this but if you're a phd student about to publish a paper on the subject and this is your FIRST TIME watching this experiment being conducted, ain't there something very, very wrong with the current educational system? i'm flabbergasted.

[@AnnaBananaRepublic]

Microscopic percolation? Is that so you can make coffee for some little critters?

[@AnnaBananaRepublic]

@@rodsmade universities only exist to train the youth to be Marxist activists

[@DecrepitBiden]

@@AnnaBananaRepublic Maybe Starbucks for narcoleptic kleptomaniacs 😆

[@Emilis2023]

Years back I majored in mechanical engineering and I still remember how much the fluid dynamics course blew my mind. When I learned how well everything in FD had a near perfect analog with electrical circuits it felt like things finally clicked in my head. Instead of living in a world with a near infinite amount of things all following their own principals and laws, most everything was more or less just different forms of the same fundamental objects and mostly seem to follow a relatively small and simple list of principals. It gives me hope that one day we may end up finding solutions to things like quantum gravity and the rules aren't as different as they look right now with our limited understanding.

[@MrJdsenior]

And thermal, and dynamics, the analogies abound. But they are NEVER perfect, they always fall completely apart at some level. I used to like to think of capacitors like buckets, inductors like flywheels, voltage and current like pressure travel and flow in a rigid pipe, etc. Like I said, everywhere. My old man, at the start of his career, used to design analog circuits to simulate missile or helicopter blade dynamics, bending moments, stability and such. And yeah, fluids was a fun, but not super easy course...compared to Dynamics though, it was fairly easy, at least for me. My dynamics prof, first day, walked in and said F is ma, you can go home now. Right, and then soon we were into Coriolis, etc. He also said he'd keep the numbers reasonable, so if you calculated the weight of a guy in an elevator to be three tons, you did something wrong. There was a big hint there. :-)

[@Adhjie]

​@@MrJdseniorlangdown bridge gang to bridge mathematics to the realm of applied science

[@rcrawford42]

I took fluid dynamics my senior year studying electrical engineering. The professor -- who was dean of engineering -- told us EE students could sleep through the fluid circuit stuff. He wasn't far off. I spent the time trying to think of fluid analogies for capacitors, inductors, and transistors...

[@zendude]

Read the book: Principia Mathematica 2: A Complete Toolkit for Hacking the Physical Universe, by Robert and David Dehister. They have a physical model of the matter-in-motion expressed with simple principles. They are able to describe electricity, gravity, light and magnetism in a simple manner.

[@WeirdDuck781]

And then quantum physics joined the chat

[@jordansorenson698]

Ever since I was in high school, I ALWAYS had an issue understanding how electricity flowed in series and parallel circuts (and combinations of such) with resistances. I never got a straight answer on whether or not current existed on the path with more resistance. This has helped solve that decade-long mystery for me. THANK YOU!

[@philipgwyn8091]

The short answer is "of course." The longer answer would be to measure the current through the higher resistance path. Your HS profs probably didn't have the equipment nor the time to do this.

[@wayneyadams]

You must have had some poor teachers because you should have learned how to calculate potentials (voltage) and current in each branch of your circuit as well as the potential drop across each resistor and current through each resistor.

[@sarowie]

@@philipgwyn8091 Ohms law says V = R * I. So by just measuring the voltage across a resistor, you already know the current. (Assuming the resistor network has significantly less resistance then your voltage meter). Most High School teachers just have no idea what they are talking about when it comes to electricity. You see that phenomenon the strongest in Physics education in Electrical/Electronics Engineering Programms: Physics education starts with Water and then teaches Resistor networks as analog to Water flow. Students in EE Programm gain intuition in current flow in Electronics 101 and then use the associations for electricity in water models in physics (exactly flipped on how the physic instructor teaches it)., because electricity is - after having it learned once - more intuitive then water. In electricity, we easily assume wires to have negligently low resistance; with water, a pipe (or any component including connectors) is always a significant resistance. Sure, you can show me cases where the resistance of an electrical wire and connector also matter, but when you reach that point, you already know to add a resistor symbol to your schematic, even if you latter assume it to be 0.

[@memebandit]

@@wayneyadams bro

[@whuzzzup]

Why did you never got a straight answer? Did you ask? This is standard highschool stuff that I teach (especially, because I hate people saying "electricity takes the least resistance way", because, as you just saw, this is just wrong.

[@dkosmari]

For the oscilloscope test, you should have used a capacitor instead of your power supply. You could show, side by side, the discharge curve of both the maze vs a simple resistor with equivalent resistance to the maze. Any deviation from the resistor curve would be the "electrons sloshing around the maze."

[@sarowie]

interesting, you assume the maze is an inductor and the "sloshing" would be an LCR resonance circuit.

[@dkosmari]

@@sarowie What do you think ISN'T an inductor?

[@Mandragara]

​@@dkosmari Still very mad about the time I was diagnosing a sensitive circuit and what was messing me up was a single loop in my probe wire.

[@gljames24]

@@Mandragara Done that before and it's annoying!

[@xxportalxx.]

I think you could also just look at the inrush current vs the steady state current.

[@carbonwolf3865]

This finally explains how electricity follows the path of least resistance. The backing up of the other routes forces the electrons to go the quickest, and least resistant route. I've had this question in my mind for a while and I finally have an answer. thank you

[@Finkle76]

I am falling further and further down the rabbit hole of the scientific side of youtube and I am nothing but hyped for the journey. Thank you for having incredibly simplified yet also complex descriptions and explanations. It ensures my attention is held no matter what level of understanding I have at the moment. Amazing content. Thank you.

[@skootz24]

Welcome! Science youtube is best youtube. Hope you find something that inspires you to experiment/try/make stuff yourself!

[@Penultimate1785]

​@@skootz24 I've been stuck. Help 😂😂😂

[@djosearth3618]

ua he's incredible eh. why does YT keep showing me ther same recomendations

[@kaushalsuvarna5156]

Hope you have seen Huygens Optics

[@PinkeySuavo]

man I wanted today to learn about antennas and im in EM waves, magnetism and electricity rbithole for last 8 hours... 4;30 am and I should sleep already

[@toddphillips8899]

An idea for the water maze; block the entrance and exit and fill with clear water, then fill the ‘input’ with died water. Unblock the start and end and the stagnant zones should stay clear with the solution turning the died color. Great video!

[@BenAlternate-zf9nr]

Yeah, I was going to suggest the same idea. You could also start it running with clear water to let it find its equilibrium and then add dye to the input while it's running. It would eventually diffuse into the stagnant mesas, but you could see the color front solving the maze in real time.

[@SpydersByte]

he has already basically done this when he filled the dead-ends with new clear water. It wasnt the point of the demonstration but you could see the entire maze went clear and then the correct path started bluing again @ 7:50

[@HenryLoenwind]

Note that you have to start with flowing clear water for this to work. When there's no flow at all, the water level is the same in the whole maze. So when the flow starts, the level in the "upper" parts will rise (adding dyed water) and the level in the "lower" parts will sink. And BTW, there still is an exchange on a molecular level (from temperature) and on a macroscopic level from turbulence. So over time, the dye will bleed into the branches.

[@ricolorenz7307]

*Dyed

[@HenryLoenwind]

@@ricolorenz7307 Careful, I'm tempted to rant about how English has no logic in which words swap between y/i/ie (while still sounding the same!) for their different forms... ;)

[@JustinMayfield]

You never miss man. Always very interesting and thought provoking content.

[@VanBurenOfficial]

🎯

[@johnfroh6774]

I have a technical degree in electricity and took several circuits and electronics classes for a Computer Engineering degree. This one single video explained how electricity works and answered questions I've been trying wrap my head arouns for years. In 20 minutes. Bravo. Thank you so much, and I look forward to your future videos explaining electricity using water that you mentioned.

[@sopik242]

hahahhaa same and we took the same course too

[@tonymccann1978]

I'm was an electrical engineer and I can safely say that your channel is the best explainer of how electricity behaves out there. Bravo, keep it up. I've binged your videos

[@KingofArsenal]

This is why I have the notifications turned on for this channel from day one, I have been pontificating the particles/waves,, Thank you and keep up the great work, I can see this channel reaching 1M+ soon!

[@bencheevers6693]

When I was in grade 6 I kept asking the teacher when we did our introduction to electricity unit "but how does the electricity know what's ahead of it, how does it decide where to go?" I like that you decided to cover this subject a lot, I have a better understanding now but you always make very informative and entertaining videos. I kind of thought I knew the answer when I started thinking of electricity like water and that made a lot more sense to me but I'm excited to see the video and see if I can get a more comrpehensive understanding.

[@sigmaxi7822]

Nice demonstration! It always delights me when someone takes precious time to describe complex things in a simple way, thank you. The whole maze/path setup is a perfect example of sheet resistance, too.

[@eggimage]

a great thing i like about your video is, unlike most others who wait till the very end of a 500 hour video before telling you the result-which makes viewers feel like getting tricked into helping monetize the video-it shows you the summary and actual secret right at the beginning, and shows in depth processes in the rest of video.

[@mariobiavati942]

I've recently started working with circuits and it's really interesting how this "self-balancing" mechanism translates to the simple rules we were explained in class

[@caniggiaful]

Showing how hard it is to measure transients on the order of a few nano seconds is such a contribution to viewers! It's a very valuable practical lesson in many ways. It is made all the more effective with the high spirits you keep as you fail to get a conclusive measurement. Respectable work!

[@AndreiDWerkhausen]

First (but not the last) time watching this channel. Much more depth, creativity and passion than I was expecting. Nice work!

[@djosearth3618]

couldn't agree more instant subbed

[@jrchannel7405]

I love the water example. I don't see it as the input "pushing" the stream through the maze but rather the output "pulling" the water through a predefined path. As if you pull a string through the maze solution.

[@AlphaPhoenixChannel]

In reality it’s both! Mhedi made a great point like this in his video with Derek - you’re pulling on one end of the chain and pushing on the the other end of the chain at the same time - both actions deliver torque to the sprocket

[@alflud]

@@AlphaPhoenixChannel See how if you have a barrel of water, a hose and a pump - you can put that pump at the end of the hose with the hose on it's inlet and other end in the water and it will suck the water from the barrel. Is there an electrical equivalent for that? It's negative pressure when you're 'sucking' water - is there some sort of negative electrical pressure too?

[@AlphaPhoenixChannel]

@@alflud There is! Conductors like to be neutral, so if you pull electrons out of a conductor, other electrons will be drawn in from anywhere they are available. In reality, it's not a vacuum of electrons, but a charge imbalance, because when you remove electrons you don't remove the associated positively charged nuclei, and that section of the material gets a NET positive charge. That net positive charge and the associated fields attract more negatively charged electrons. Hope that made sense

[@wayneyadams]

@@alflud Yes, the cathode repels electrons while the anode attracts electrons so its like a pump pushing water at one end while "sucking" water at the other.

[@kindlin]

@@wayneyadams It's kind of both at the same time, but really a circuit is just that, a round circuit of wire that has to connect back on itself, a loop. In that sense, the pump is really what the battery is doing.

[@Viaexplore]

Those 5ns riples are reflections in your maze. Touching the wire is producing diraque pulse which is propagated thru your maze. Every end or blind end will reflect that pulse back to source which depends on impedance. Add capacitance, inductance and resistance to your theoretical model and you will get your voltage readings on your scope. You can even do FFT of your response curve and you will find out that there are certain frequencies peaking up. Those are based on length of each branch in your maze. Each branch is now also a peace of tuned RF antenna. And remember, electrons are very slow in conductive material, the interaction between the electrons and overall propagation are what is almost as fast as light in vacuum.

[@BitwiseMobile]

Also, remember as electrons pass a gap they WILL generate RF. That's how RADAR and Klystrons works essentially. That maze is probably noisy as all get out in the RF spectrum.

[@KarldorisLambley]

" diraque " will say that or tell you, in french?

[@PigeonLaughter01]

I'm glad I'm not the only one that thinks in rf! 😂

[@arthurmoore9488]

@@PigeonLaughter01 You say RF, I say black magic. Then again, the difference between a Computer Engineer and an Electrical Engineer is I didn't have to take Emag.

[@the_ALchannel]

You probably meant Dirac pulse, and in that case a step pulse would be more accurate, dirac is short singular impulse

[@mikekrywko2990]

Love this channel. As a corrosion specialist who works on pipelines, i.e. cathodic protection, ac powerline interference, materials engineering, etc, i think this channel might be my favorite. I really like how excited you get about the science. Awesome job.

[@FalcoGer]

My guess for mazes with two solutions is that each path has some resistance R1 or R2. Given a uniform material, any one length of material in one path will have the same resistance as the same length in the other path. So the resistances are proportional to the length of the path. The current will split such that is split between the two in the ratio R1 to R2. So the less resistant path will see more current. The power dissipation is P = U * I. The voltage drop across both resistors is the same because they are connected, so the shorter path with more current will heat up more. The maze with two paths is equivalent to two resistors in parallel, which is grade 5 physics textbook stuff.

[@degtyarev708]

Been working with electronics at the hobby level for years, and this has always been something I *know*, but never intuitively understood. One demonstration and everything immediately clicked into place. Love it, good work man!

[@Afitz200]

What a beautiful video. You tied together several high and low-level concepts of electromagnetism and with wonderful visual examples that are easy to parse quickly. Great work, I truly enjoyed this!

[@Oscar-vf9tg]

Awesome video! The way you explained it is so intuitive and easy to understand with examples and refering back to simple concepts. I wish I had this back when I first learnt about electricity

[@DiogeneDeSin0pe]

So cool how you referenced two videos I previously watched. Using the water maze horizontally was even better.

[@andrewmattern8185]

Bro, I'm just gonna say it, you're awesome

[@dmeemd7787]

Agreed!

[@VanBurenOfficial]

Holy carp you actually said it m8

[@goat5249]

I've loved watching your channel grow. From all your subscribers to your Ph. D., I just wanted to say "Congratulations!" Thank you for all of the wonderful content!

[@tristan95]

You always put so much effort into explaining things simply. Really love your videos.

[@dhy5342]

Your multi-path experiment reminds me of a similar idea I had many, many years ago when I was much younger. Way before GPS was a thing I drove a cab for a couple of years. Routes driven were highly subjective and may or may not have been optimal but paper maps helped in many cases. My idea was to create a road map using lengths of wire to represent streets and each intersection would be the relevant wires joined at the junction. At the mid-point of each street between intersections, there would be a small bulb that would light when the current passed that point. One-way streets would be controlled by diodes in the circuit and in an improved version, speed limits would be controlled with resistors in the circuits. The ultimate thought was that probes would be clipped onto the starting and ending points, and a string of lights would show the shortest (and quickest) path to take. I never got to a testing stage with the idea which is just as well since the covered area of 750 square miles had over a thousand streets covering over 500 miles and probably a dozen or more ways to get from point A to B. The resulting map would be totally unmanageable in size and either all the bulbs would light or, more likely, none would be bright enough to see.

[@youvebeensubbedto8009]

I love the water model for electricity! It's what really solidified my understanding of fundamental electronics. Looking forward to the (hopefully) coming video :)

[@__dm__]

I'm an electronics engineer and I thought of the electromagnetics of the foil maze which I understand quite well, and that actually gave me insight into the water maze haha

[@sarowie]

@@__dm__ When obsessing electronics students, it is always a good sign when they start to use electricity as a model for water system. Really funny when the physic instructor tries to explain electricity with water models to EE students and they apply the tabels in reverse, because electricity becomes more intuitive then water after solving various resistors networks in Electrical Engeering Classes.

[@jmlatimer]

@@sarowie We treat heat transfer as energy flow through a resistive system when modeling it mathematically as well.

[@cablebee8790]

Do I ever struggle to solve mazes, you ask? Yes, I have indeed played The Witness…

[@henningerhenningstone691]

This is an awesome visualization! It also makes the formulas and calculations in electronics more logical to me. In the end, all electronic circuits are basically just a maze, where the measure of resistance of a certain component tells you how "long" that component's "path" is, and the voltage drop over a series of components gives you the "gradient" of the "water hill"

[@DeusExNihilo]

this just gave me a great idea for a D&D scenario. The players find themselves in a dungeon maze and there's an aqueduct near the entrance. Maybe there's already a leak in the aqueduct with a little stream running down into the dungeon and some wood barrels near the entrance to give the players a hint on how to solve it.

[@chopper3lw]

WOW.. I've been torturing electrons for over 40 years and have never seen such a great demonstration. Nice Job!

[@CharlieBurrows]

Great video as usual. Two things I would have liked to see: 1. When you poured clear water onto the maze but kept pumping dyed water it would have highlighted the solution very nicely. 2. Multi-path water mazes. Maybe starting with clear water flowing and adding a dye tablet in the source basin would have yielded different strengths of colour in the two paths.

[@mazocco]

I bet you wrote this before watching until the end

[@BenAlternate-zf9nr]

I think with adding dye to a multiple-path water maze, they would both end up the same color, but the dye color would propagate more quickly through the shorter path due to the faster-flowing water.

[@robbolles4742]

Thank you very much for all that you demoed. This has been huge to my understanding of circuits.

[@SamanBahrampoor]

Dude, you're such a great engineer/physicist/educator. Amazes me every single time!

[@clover7359]

Wow, that was a lot of work but it was definitely worth it because this demonstration was every bit entertaining as it was educating. Really nice explanation of everything.

[@catalyst012]

I have just never seen a teacher explaining things in such an interesting and easy way! What a fabulous mind!

[@lastchance8142]

Awesome experiment! Thank you for for the many hours you obviously labored to produce this excellent demonstration!!

[@VincentvanFlow]

This was a great video. A slightly more technical way to put it that is also helpful is that all conductive material, including wires, have capacitance. A capacitor is like an electric spring, same equations as a spring. Compressing the electric spring is the same thing as the filling up of the maze with water. When the voltage is removed, they will "slosh" out, or sort of pushed out like a spring releasing compression, as the charge of the maze reaches 0 again. I always found the spring analogy helpful.

[@joseramonlopezblanco7558]

Great video, just a couple recommendations: 1) What about glueing the mazes to some kind of base to avoid annoying perturbations in your tests? 2) As a cheaper alternative to lasser cutting... you can use conductive 3D printer filment instead 😊. Thanks for the interesting video!

[@calum.macleod]

While watching this I had three thoughts. 1. After a four year physics degree, I think I would prefer to have had Alpha Phoenix as my high school teacher, than my university lecturer. Your ability to take complex and even controversial topics and make them accessible is fantastic and all young people should watch your work. 2. I am quite obsessed by super-high time-resolution photography of stepped leaders. Obviously an oscilloscope is going to have trouble seeing the EM fields, feeling their way around a maze. But perhaps a huge maze with atomic clocks scattered around could allow us to see the equivalent of stepped leaders in an electrical circuit? 3. In the very last pictures, why does the circuitry heat up so much more, at the corners of the maze? I get how, for example, racing cars have friction when they get to the corner. But how do EM fields or electrons know to expend more energy at the corners of a maze? I am fascinated by that picture!

[@djosearth3618]

that's what he asked but you like me already agreee with his posit thus already assumed to equiv to water flow.

[@APF3LKUCH3NLP]

All of this is just awesome! Amazing, thoughtful and beautifully demonstrative experiments 💜

[@robfhiuo1]

I love this. I had a hard time visualizing and understanding electricity as a student until I started using water as an analogue - great experiment.

[@14ajencks]

1:13 this man, sitting with a casual 2.4 Amps of current running through his maze there

[@matthewkilner]

That's a really beautiful demo. Thank you.

[@LightTheUnicorn]

It was really cool to see a practical demonstration of this, and the explanation was really easy to follow. Great stuff!

[@PIXELamPC]

aMAZEing

[@AlphaPhoenixChannel]

Ba dum tss

[@mqb3gofjzkko7nzx38]

I'm guessing that the electricity will treat each valid path like a parallel resistor. A larger portion of the total current will pass through the shorter path.

[@dereknalley]

That video was complete badassery. Well done!

[@TravellingTheWorldWideAndLarge]

Very nice experiment! It illustrates Kirchhoff's circuit laws in an interesting and engaging way. The different paths to "solve" the labyrinth are wires of different lengths and can be seen as resistances of different values. For two resistors in parallel, more intensity will flow through the least resistant one and so it will heat up more.

[@WalterSamuels]

A good way to think about it is that once the shortest path has been found, it's like a pulling motion from the end of the maze, rather than a pushing motion from the beginning. Now the water is being pulled through the maze from the end of the maze, so it's always following that path (despite very small deviations here and there).

[@-danR]

That's a way to _think_ about it, but it does not correctly portray a solution. The solution is in the video, and it is not in theoretical equivalence with any pulling mechanism.

[@WalterSamuels]

Yes it's theoretically equivalent to think about it this way, the pressure differentials along the path are what define this behavior, and that two-way equilibrium is only established once the path has been located. The added tugging force (pulling motion/negative pressure) is what allows for this path to dominate over the other paths. Without it, as you can see when the maze is closed, or when it hasn't located the path yet, there is nothing to enforce that particular path. So it is more clear to think about this from the opposite end once the path has been established, as this is what is maintains that behavior. It works the same way with the electricity example as well, negative and positive EM radiation pressure. @@-danR Btw, the "solution" (it's not a solution) is wrong. This is not caused by water level, that is just an observational byproduct. You can read his pinned post that confirms this as well if you need to appeal to an authority.

[@thefreshwes]

Instead of pulling, I like to think about it like the electrons get out of the way. Imagine rolling a basketball down a highway of AI driven cars (all going the same speed). The ball will follow the path of least resistance.

[@sagewaterdragon]

Electrical engineering was always my weakest point, I'm always glad when you make videos about it. Excited for the eventual hydraulic analogy one.

[@ipaqmaster]

Great video loved the callbacks to Grady and Steve's uploads, other great channels covering theory with helpful practical examples. Loved thoughts being confirmed by the excel visualization. Had a jump saying "back to equilibrium" out loud then thinking maybe that wasn't the right word and was immediately followed up by the video saying it too

[@Sarcose]

Thanks for the recommendation on how to solve mazes. This is so much easier than any other possible method!

[@Whytho2000]

I will say, that I'm glad I'm an ME instead of a EE or a Physicist. The EE world and the Physicist worlds never quite made sense. The explanation for electricity acting like water, but not really, and that it flows one way but is represented the opposite way mathematically, and then that electrons move, but not really, was just too much for me to be happy with. The same goes for physics. Physicists will ask a question on an exam, and just expect that you can intuit things they never taught in the class. I still love watching channels like yours to get a sneak peek into your worlds. As ME, CE, EE, Physics and all other branches of science are all interconnected at a fundamental level. Its fun delving deeper :)

[@KarldorisLambley]

i would never want to use a ME who confessed to disliking physics!

[@Whytho2000]

@Dorian Anreiter sorry I should have specified quantum physicists that ask questions on exams like, if you were an an astronaut floating in Space with a flashlight pointed in one direction, starting from zero, how fast would you be accelerating after 10 years? The prof straight up skipped how much momentum light imparts. And just assumed everyone knew that stuff

[@KarldorisLambley]

@@Whytho2000 lol. that makes sense. thanks for your polite reply

[@joeleagles5491]

Also good to remember that heat and resistance have a linear relationship. Meaning the hotter it gets, the more resistance it has. So as the line heats up, it can increase resistance to the point that the longer path has a lower resistance (to a certain point)

[@1ch190]

Plasma is a thing

[@FR-ce2tk]

We use the saying...."path of least impedance" at work. It's a good way to always remember that a lot of devices or circuits use both AC and DC and it reminds you that capacitive reactance and inductive reactance can play be huge factors in how that circuit operates.

[@chrisdekock8864]

Well done video. Love your practical explanation on the excel graph with the water level. Great job mate.

[@52flyingbicycles]

The electrons in current move extremely slow, but electrons are tiny and their force is strong. Through the entire life of a power plant, the electrons in the main conduit may never leave the premises, but they force other electrons to move, which force other electrons to move, and can move electrons hundreds of miles away

[@grandsome1]

So following the water analogy, the flow of "current" is the gradient of the pressure of the water in maze. (Actual hydro-engineer or physicist correct me.)

[@tl880linux]

Looking forward to the hypothetical video where you go full circle and somehow connect that maze water level diagram to material grain boundaries or crystal defects

[@nucle4rpenguins534]

Super cool idea; this reminded me quite a bit on how electrical resistance of a wire can be defined in terms of the wire length. In this maze game I guess you work in the limit where the difference in wire path lengths is significant to show a noticeable difference in current. A cool follow up experiment is if you can mimic this behavior where instead you swap the extra long wires for resistors of near equivalent effective resistance, and see if you get the same proportions of charge flow down each path!

[@user-ou3ul6or4d]

Awww the maze, my favorite medium of simplicity to be able to find solutions. Such beautiful plain medium 😊

[@ianmercer1291]

Id be curious to see if the path for those multipath mazes changes if you changed the cross section area of the foil at different points. Id expect thinner parts to maybe act like resistors. If that was the case it would still make sense with using water as an analogy for electricity.

[@AlphaPhoenixChannel]

Yup! A thinner path would behave like a longer path, and it IS still very well-represented by the water height=voltage shtick! I shoulda done that… Actually come to think of it I kinda did with water! For the 2-path water demo, I had one that was printed the same width as the maze channels and it wasn’t dropping enough voltage -I mean height- so I thinned the channels to 2mm wide 😁

[@pikapomelo]

This would be interesting to see. I understand that the paths for current are acting like resistors and longer paths lead to higher resistance. I also get that thinner paths have higher resistance. Would be interesting to see the pattern of a solid sheet of foil. The part that is confusing to me is the real world application. From soldering simple analogue circuits, the gauge of wires or traces doesn't really seem to make any difference, I guess since the scale is so far off from the resistor components etc. Thanks for the videos and comments!

[@Hirosjimma]

​@Robert Swaine A weir is indeed weird It completely blocks flow under a certain threshold, and once over that threshold its resistance goes down as potential goes up. What electronic doohickey does the same?

[@alexholker1309]

@@Hirosjimma Zener diodes, particularly a pair of reversed Zener diodes in series?

[@ianmercer1291]

@@Hirosjimma I think what's really going on is in a Forward bias situation you get an exponential relationship between voltage and current. But when you're in a reverse bias you get a really small current until you surpass the breakdown voltage. I think it's also good to represent that in terms of current and voltage because diodes are typically shown in terms of their IV curves (current vs voltage). Just like how a diode behaves, the band structure even looks almost the same as the physical weir. But also like the weir and a diode, you need a small forward bias to go down the weir, but a large reverse bias to go the other way, until you get to the breakdown voltage.

[@PaulMarostica]

AlphaPhoenix: It appears that the paths you used in the mazes all have the same width or cross sectional area. It might be interesting to also vary the path widths or cross sectional areas to show how water and electricity flow in those mazes.

[@barefootalien]

I think having all of the paths equal width for the water maze is the best analogue to the electric mazes. As far as I know, unless you're pushing the material close to its limits, heating it up enough to change its resistance over time significantly, the electricity won't care how wide or narrow the paths are. That's one of the ways in which the water-electricity analogy breaks down, unfortunately.

[@PaulMarostica]

@@barefootalien I think wider path results in more flow.

[@barefootalien]

@@PaulMarostica Yeah, it would. I was pretty tired when I wrote that earlier, heh. Resistance is inversely proportional to cross sectional area. That foil is actually quite thick to an electron, something like a couple hundred thousand atoms, and should remain constant, so that should translate to a linear relationship for the width of the foil, as the only variable in the area. So yeah, half the width should result in half the current. Now I'm thinking about how that would affect the brightness of the wire in IR... Heat is proportional to current squared, so a path twice as wide would generate four times the heat, which seems clear enough... However, it also cools itself, so the steady state is reached when the heat in equals the heat out. Heat out would come in several forms... Radiative heat dissipation (what the camera sees) is proportional to area and... I want to say the fourth power of temperature (in Kelvin). However, that camera is only capturing a narrow bandwidth of infrared light, and because of the constraints on black body radiation, the peak could move in ways that seem like they'd be non-trivial to calculate. He's also doing it in atmosphere, so there's convective heat loss as well, which is proportional to area, relative temperature to ambient, and speed of air movement, if any. I think it'd be reasonable to assume the foam board he's doing it on doesn't contribute much in the way of conductive heat dissipation, at least. Heh, maybe you're right... this _would_ be an interesting one to play out in another video. I'm sure it _is_ calculable, I just don't especially feel like it at the moment, as I'm about to go to bed. xD That said, it'd be more of a 'teasing out fine details of several physical processes' video and less of a 'here's a neat analogy to help you understand how electricity behaves' video.

[@PaulMarostica]

@@barefootalien I wish you good luck if you do try the calculations you've mentioned.

[@carlosrossembergcubasalcan7474]

Thanks so much for such a great video. It really makes sense now how electricity follows the least resistance path, It's not because it always knew where to go but because it "test" all the paths! And choose the one that takes the less effort to complete. You just won a new subscription!

[@marcoottina654]

That's an awesome quality video and explanation! Great!

[@Ordolph]

I think the "usage" of each path is going to also depend on the amount of current you're pushing through. If you start pushing enough that the shortest path gets hot enough to raise the resistance, then the longer path will start getting used and the system will find an equilibrium.

[@gingermany6223]

Something tells me this took longer than planned to setup and shoot 😂

[@AlphaPhoenixChannel]

Haha this is FAR AND AWAY the fastest I’ve ever produced a “full” video… most of my pieces to camera were filmed yesterday. It normally takes me weeks to edit something like this but this was an abnormally animation-light script 😁

[@gingermany6223]

@@AlphaPhoenixChannel nicely done. So on the order of 10x faster?

[@Pants4096]

@@gingermany6223 closer to 12 ;)

[@gamingclipz7309]

Love it!! So happy you have new videos!! You helped me get over my depression and anxiety and now I’m in love with all things science I’ve found doing projects help me sooo much. Ty for the amazing content my friend! Stay blessed

[@JasononaBike]

I just stumbled onto your channel and I love it, thanks for all the great content! One thing that crossed my mind listening is that I believe you'd benefit from a higher quality mic and audio setup. Specifically I went and watched Steve Mould's video that you recommended and when I came back the contrast between audio setups was clearly clarity :)

[@AskYourStupidQuestions]

6:00 that would be a cool idea for world generation.

[@TheRetroEngine]

Wow this is normally the kind of questions I come up with, this is explained SO well. Nice one.

[@stevesloan6775]

Just so you know, this video is well worth, a heap of skips backwards, plus a full rewatch. : ) Great content man.!!!

[@Moohasha1]

VERY cool visual representation of what's happening!

[@DarnokPL]

I love intuitive videos like this! :D

[@ChrisMasto]

I'm sure someone else said it in the 1000+ comments, but that last demonstration was also a good explanation of why an inadvertent low-resistance path is called a "short circuit" and why it's a problem.

[@F_L_U_X]

I love the vocabulary that you use. It mixes will with what you're trying to describe. Maybe you're just that good. Maybe we're just similar. Whatever the case, I enjoy your videos A LOT!

[@billymanilli]

Wow! This might be quite literally one of the COOLEST things I've ever seen!!! THANKS!!!!

[@jimited1]

What an amazing explanation, thank you!

[@masive61]

It is amazing how I was so hooked watching this video. I've always enjoyed watching and or learning about stuff like these but what really amazes me is the "of course" moments. Watching this internally trying to come up with answers like how the electricity will solve the 2nd maze and when it actually happened, the feeling of "of course it did that, it was so simple why didn't I think about it first". It was the same feeling i had first hearing the story of how isaac newton discovered gravity. It leads me to believe that there is a whole lot of thing that we are observing with everyday but still yet to comprehend the magnitude of how they will affect future science.

[@palmettoblend24]

Unironically the best explanation of electricity I've heard.

[@macronencer]

Really enjoyed this - thanks! Electricity and mazes were two of my favourite things when I was a kid, so it was a perfect piece of entertainment :)

[@sgtcrtrdnl]

Fascinating expirament and report!

[@ArifSoylu]

Unbelievable good demonstration of plenty of things

[@FtLongFry]

"how does current find the 'path of least resistance' " is something I've honestly questioned for a very long time (but was too lazy to do real research lol) thank you so much for laying out the perfect answer so clearly!

[@alittlebitgone]

The answer is it doesn't, you caught that right?

[@iamuzairahmad]

first time seeing this channel and i subscribed immediately after seeing the intro. he didn't beg, he earned it

[@Mad_Bun]

EE approved! What a great metaphor and visualization to help people learn electricity intuitively!

[@Elkhaligy]

Great experiment, much fun!

[@TolisOnLine]

22:07 Just after you made the "snip", on the other path, the heat builds up around the bends first, while the straights are cool. Fascinating.

[@CostasLilitsas]

Beautiful Work!!

[@swedishpsychopath8795]

Thank you Norway for inventing this techonology and spreading it to the world.