AlphaPhoenix - 2023-12-06
In this video, I measure a wave of electricity traveling down a wire, and answer the question - how does electricity know where to go? How does "electricity" "decide" where electrons should be moving in wires, and how long does that process take? Spoiler alert - very fast! I've been very excited about this project for a while - it was a lot of work to figure out a reliable way to make these measurements, but I've learned SO much by actually watching waves travel down wires, and I hope you do too! There will be a Q&A about this video posted in a few weeks on the second channel, and if you head over there right now, you'll see two direct follow ups to this video with experimental details, and a section about "impedance matching" that was cut from this script. https://www.youtube.com/@AlphaPhoenix2 Special thanks to my top Patreon supporters! birdiesnbritts John Sosa Trustham Vladimir Shklovsky Aloysius Sparglepartz Ryan M Jason Whatley Lohann Paterno Coutinho Ferreira Kasper Nielsen Jeffrey Mckishen https://www.patreon.com/AlphaPhoenix Media Credits: Slomoguys clip used with permission. Thanks Gav! https://www.youtube.com/watch?v=nsJGJHkJolI I Dunno by grapes is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/...) http://ccmixter.org/files/grapes/16626 Arcadia - Wonders by Kevin MacLeod is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/) Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100326 Artist: http://incompetech.com/ 0:00 a hypothetical question 3:30 Measurement difficulties 7:44 Individual oscilloscope traces 10:23 Electricity moves through Y circuit 12:54 The single wire experiment – how electrons move 17:32 Electrons hitting a dead end 20:23 Revisiting the Y circuit 22:16 The water channel model
Excellent video, those data-driven animations are extremely clarifying. I'd never seen someone show a circuit settle into a steady state like this, thanks for putting in the effort.
Glad you liked it! (Don’t worry, I’m a big fan of math-driven animation as well)
Does it settle to a steady state? Or does it ring with ever decreasing amplitude, forever?
It's blowing my mind just how accurate the water analogy is for electricity.
Totally agree!
@@StreuB1 so there will be a moment when the interactions will reach smallest possible energy transacttions between electrons given from quantum mechanics, but in these "large" systems it is afaik effectively infinite, but mathematically you can say it is definitely not
Well this is ridiculously cool. This makes electricity make so much more sense, and what an amazing visual!!!
nerd
This is a fantastic endorsement. I recently purchased a VNA, and learning to use it helped me understand impedance and transmission so much more than anything I learned in school or from reading. This demonstration managed to be every bit as effective, which is amazing that it could be done with just a very basic scope and stuff from the hardware store. Bravo!
Hear Hear. This a demo that all scientific communicators can aspire to match. Bravo.
And then you go to uni and learn that quantum field theory shows that it was all a lie. ;)
Here is another way to think of this circuit. The open end twisted pair are a capacitor and and inductor. The normal charging constants for a cap apply. The shorted end is more of a pure inductor, again the normal constants apply.
I love how you actually showed the waves! TO knowing is something, to seeing is something else!
If you want to see more waves, I have the follow up on the second channel with impedance matching - I learned so much watching these animations!
Retired in 2013, teacher in HS and college adjunct with MS in Physics. Love the graph with the animated bar graph and point electrons below! These tools weren’t available when I was still teaching, but this is something I for sure would have had the kids watch! When I first saw it run, I totally geeked out on the reflected wave. Just like a compression wave in a spring hitting a barrier, or light ray entering a different refractive index… I started thinking about wave-particle duality of the e-. I’m so glad you went to it in the second half of the vid! Thanks for the mental stimulation, love your work!
As someone who has worked for quite some time in the field of non-destructive testing, I was already quite aware of wave phenomena, when they encounter impedance boundaries. It's wave physics in action, with all kinds of mode-conversion options that can be utilized, such as longitudinal - transverse and vice versa. We also used so-called Time of Flight Diffraction techniques, in which we recorded a B-Scan of a weld examination, showing the longitudinal reflections and the mode-converted transverse reflections in the same representations, as well as the diffraction echoes that indicated the ends of a fissure or other small discontinuities in the parent metal. With mere pulse-echo techniques, these small echoes would certainly have been missed.
That graphic at 10:50 is amazing.
One of the best things ever uploaded to YouTube.
Certainly! Deserves a video on its own
😊
I know man, that was so cool.
Waiting for the collab
Fun fact to this video: Since the waves reflect once there is a change in the wire, e.g. an "unexpected" open end because the cable was damaged somewhere, the time between connecting the battery and the the arrival of the reflected wave can be used to measure how far away the fault in the wire is (its called reflectrometry). This is extremly useful when diagnosing where cables buried in the earth are damage so that you can dig up exactly the damaged section instead of having to dig up kilometers of wires until you find the faulty section.
At the airport I work at we recently had an underground wire break. The local electrical repair company came out to locate the break. They used a trailer that utilizes the principle you described. We call it the ‘Thumper’ as you can feel it in your feet when it sends a high voltage spike into the ground to the break.
One of my friend's masters thesis used the same principle but for sound in water pipes.
@@RovDisco Thumpers like that are very primitive compared with time domain reflectometry gear. Modern form factor is a single-unit handheld (e.g. ONX-580) that can tell you exactly how far away your different faults are on the line. You'll get a different signal back for an open branch line vs. a short vs. something else...no need to even put anything at the far end of the line, although you can if you want to confirm a certain pair of wires really does take the path you think it does.
@@TwoTreesStudiotheir primitive reading is more than necessary for their purposes I am sure. They need to access a fairly large section to make repairs.
Just how accurately can that be calculated down to?
100 feet?
That bar graph animation was one of the single best scientific visualizations I’ve ever seen, all the more compelling because it’s empirical, not simply modeled. Fantastic.
@@sIXXIsDesigns no 2:39 pretty much nails it
It was really good
Modeling is the death of science.
Just outstanding! Did Hon Physics to 18, and Engineering at Uni. Not once did I ever have someone so good, give such a comprehensive journey of "investigation " of all aspects of Ohm's Law with such compelling evidence of its disection! THIS is truly science explained, evidence based, and married to the theory and maths! The depth of knowledge required to be able to deliver this video is mind boggling!
Modeling - hmm? Too many ways for it to go wrong, short cuts, assumptions.........
Give me videos like this EVERY time! You don't get understanding like this from Modeling!😂
@@bluenetmarketing How would you do it
I’m a ham radio operator, and one thing I’ve always struggled with is how antennas work. An antenna is basically just the open circuit you demonstrated. The reason that we have to make antennas very specific lengths is to create a standing wave of voltage. The more pronounced that standing wave is, the more energy is radiated as EMF.
I know your goal in this video wasn’t to explain how an antenna works, but your explanation really made that make sense to me.
Absolutely amazing “footage.” Who needs expensive cameras when you can get such good data from an oscilloscope. 🤯
I’ve been trying to do the math to make something like a streak camera using oodles of repeated scope traces but finding LEDs with nanosecond ramp times is challenging xD
Sounds tough, hope you find them for the epic visual next video
@@AlphaPhoenixChannel Maybe LEDs aren't the ideal light source? Surely a spark gap could faster?
oscilloscope is a camera, for watching electron potential :)
actually i was wondering when i saw the video title, how a "camera" of any sorts could "see" electrons in a wire.
But he found the solution: multiple repetitions of the experiment, with oscilloscope probes at varying locations. Great.
IMO this is hands-down one of the best physics channels on YouTube. Your ability to turn highly abstract and complex concepts (like the "speed of movement" which is a video I'll never forget because it blew my mind) into real-life experiments using actual measuring equipment is just amazing.
I like it when someone takes a seemingly impossible problem, and breaks it into easily solved chunks. Brilliant!
The intuitions for (S)TEM microscopes and voltage is what sold this channel to me. Now it’s going to get better.
I have a bachelors in Electrical Engineering and have worked in the profession for 34 years (retired). I have never seen electricity explained this intuitively in college or at my job. This was awesome. The similarities between fluid and electricity behavior are so useful to help understand electricity. It's a very tough thing to grasp due to how fast things happen on an atomic level. You figured out a creative way to capture it.
Agreed. I struggled with these concepts initially in college, and an explanation like this illustrated the concept perfectly.
Yeah, I always pictured the initial wave explaining switch voltage spikes, but I always assumed it would dampen much faster than that. Seeing the electron loading bounce back and fourth almost 4 times before being dampened to equilibrium with the motive force was impressive.
My understanding is the electrons do not move , the electric field moves out side finds the electron at end of wire or switch junction whatever , They all teachers say electrons move yes but not in the way we think about movement in that way they don't
@@rolandhawken6628 Electrons are moving from one pole of the battery to the other in an electro-chemical-thermal reaction.
@@runbigfoot I was referring to wire
This is THE BEST explanation of this topic that I’m aware of. You made a test system and took exacting enough measurements to figure out what is going on, and THEN on top of that you made this video with clean uncluttered graphics and clear explanations. Bravo!
As a physics educator at a university, I love this video for so many reasons. First and foremost, this was amazing science done right. You presented a problem, made a set of competing predictions, established what data you were going to collect and related your predictions to your data (you said what we expect to see in every different case), then you took a copious amount of data (p<0.0000003 like a good physicist), you analyzed it well with lots of figures, and you discussed how it confirms only one set of predictions, discounting other theories. Great science, dude, A+. The second reason I like this is that it doesn't hype up the science artificially. You let the science make itself awesome, unlike certain other YouTube creator (looking at you, Veritasium). And third, it reinforces my own sense of "yes, I know what stuff does because I'm a physicist". When you asked the question I was like "obviously C, because it shouldn't be able to do the other options". Nice to see I know my stuff. Honestly, I wish I could teach my students to understand the scientific method as well as you seem to. If you were in my lab course, I'd give you the A+ and tell you not to come back. "Student has demonstrated all skills that we are trying to teach in this course. Credit granted with 0 revisions"
Nice comments, and yes, thanks for your reference to Mr. veritasium who instantly came to my mind while viewing this......for all the wrong reasons !
I’m a glutton for data 😁
My favorite part of this experiment is that it demonstrates that, yes, electricity is made of actual "stuff" while also demonstrating that the actual information which defines a circuit must somehow travel at some speed.
@@AlphaPhoenixChannel Is this research correct? Unlike a simple Y wire with closed and open ends, the developed circuit already becomes an “inductive” circuit, moreover, with a connected oscilloscope completing the circuit.
верно ли это исследование? в отличии от просто Y провода с замкнутым и разомкнутым концами, развитая схема уже становится "индуктивной" схемой, более того с подключенным осциллографом замыкающим цепь.
@@gt_xpert I am very from an expert but my understanding leads me to believe that all circuits have some degree of inductance (because they all involve current flowing and therefore create magnetic fields). Furthermore, the question wasn't what happens in this exact set of of wires with this exact resistance and this exact inductance, it was: "how does information travel in a circuit" which is much more general and I believe very very very well shown here
Your vids have already changed my understanding of electronic fundamentals, but this visualisation in particular absolutely took it to the next level. Thanks.
I wish my children would understand that learning should be fun.
Check out the video looking glass universe released on refraction. It really helps to understand the electric field and what photons really are.
@@chrisspere4836i mean it's your job to make it fun for them, no?
This video should be played in every school, I'm an electrician and never saw this explained this good
As an RF Engineer, the stuff you're talking about is my daily bread an butter. Still, I've never seen such a good visualization of electromagnetic waves, let alone based on actual measurement. Really cool and educating, even for professionals!
I'm also and engineer for a prominent company that designs/produces RF power supplies for plasma sputtering, semiconductor etching, metrology, etc. However, I design and write regression tests for our firmware. Specifically, I test the product that does dynamic impedance matching between power supply output and plasma load. Who do you work for? I wonder if we work for the same company ;)
Reflections are a big part of our zeitgeist, and I agree that this video does an excellent job visually representing what reflections are and how they work.
@brentsmith7013 what I found interesting when first learning about RF, is how much more consequential everything in the circuit is. Like an axial resistor isn't just a resistance value. The leads and film material also act as little inductors and a capacitor in the circuit (to your point). I have a ton of respect for RF engies, because they are doing calculus vs me doing basic algebra.
Also an RF engineer, and also very impressed! The old adage that only a real expert can explain things simply really applies here.
Hobbiest RF guy here. I'll be using this video to talk about wave propagation in a transmission system, why we open/short/load a DUT, and more when I teach potential licensees...
Speaking of RF, I'd love to see this experiment repeated with Litz wire so that we can compare them. I think that would be super interesting.
I read down quite a number of comments looking for the key words, in engineering speak. Not finding them I decided to write this comment.
You did an excellent job of revealing a phenomena that has been understood since the time of copper wires for telephone circuits. Your wires constitute what is called a transmission line: The wires have a finite total resistance, and some amount of capacitance over the length of the twisted wire path. It is that resistance and capacitance that are responsible for the waves and reflections you measured. What you did was create an instrument called a Time Domain Reflectometer! With just a bit more math you could have determined the lengths of each section of wire, and where the Y-point was, just from the graph on the oscilloscope. Kudos on your achievement!
I’m an electrical engineering student. I remember learning this in circuit analysis but this visualization is so much better than the things we had.
I am an engineer (electronics) and I hated transmission lines. I got around that after someone told me to stop looking at the equations as an engineer and more like a mathematician.
If your school offers it and you're at all interested in this type of thing, I'd recommend taking High Frequency Systems. No doubt one of my favorite classes.
i am not an engineer but i am assuming that this is a representation of inrush current?
@@Hullad1379 Transient response.
I’m a sparky and you’re exactly right! I wonder if an led would light for a nano second if forward biased on the open ended pair, due to the rolling voltage gradient?
Holy cow! I have a masters degree in physics and this is one of the most intuitive and understandable explanation of electron flow I've ever come across. I'm amazed on how much information you could gain with this "basic" setup. I also love your systematic approach and the brakdown of the system. Very well done sir!
It is not electron flow, it is the propagation of guided EM waves on the wire.
@@msf60khz at least i know now physics majors are not gonna steal my electrical engineering job
@@msf60khzthey’re the same thing 🙃
@@flowildfellow electronic engineer here — @longnose154’s model is perfectly accurate because electron movement and wave propagations are analogous models for each other — basically half of the point of this video is to explain this 🙂
THERE ARE NO ELECTRONS. CHARGE IS BOTH POSITIVE AND NEGATIVE. METALS HAVE FOUR FIELDS. +/- STRUCTURAL AND +/-FREE CHARGE. WHEN YOU CONNECT THE BATTERY THE INDUCTION FROM THE POLES ALTERS THE RATIO OF +/- STRUCTURAL CHARGE COMPENSATION AVAILABLE FOR EQUALIBRIUM CONDITION OF THE METAL AND THE PLATES OF THE BATTERY.
ALL MATTER IS MANIFESTING FROM THE AETHER CONTINUOUSLY. NEGATIVE AND POSITIVE CHARGE FLOW FROM THEIR RESPECTIVE POLES OF THE BATTERY TO COMPENSATE THE INDUCTIVELY MANIFESTED ALTERATION OF +/- STRUCTUAL CHARGE CAPACITY IN THE METAL OF THE WIRE. AETHER/HEAT IS UNDIFFERENTIATED +/- CHARGE WHICH DISSIPATES LONGITUDINALLY NOT ELECTROMAGNETICALLY FROM THE WIRE. THERE IS NO MAGNETIC FIELD AROUND A ROUND WIRE, OTHERWISE THE WIRE WOULD BE ATTRACTED TO AN IRON SURFACE. THERE IS AN ANISOTROPIC PERMEABILITY TO MAGNETIC FLUX CONCENTRIC TO A ROUND WIRE OF THE CLOSED CIRCUIT. A FLAT CONDUCTING WIRE WILL ATTRACT IRON AS WILL TWO PARALLEL WIRES CONNECTED TO THE SAME BATTERY POLES AT THE SAME ENDS.
This channel is like a saving grace to people who already know the math and feel the physics but don't quite get it. It feels so good to understand what you thought you knew.
Yes, it remembers me what I learned decades ago on microwave wave guides and printed circuits. But it was all maths and fields back then, and harmonic signals. I never figured what could happen to electrons in conductors, specially the pattern of "charged" wires in an open-circuit DC line.
This is proper science, purely driven purely by experimental data with a heap of tedious attention to detail and not a slave to some fragmentary theory. Wonderful. Some discussion/exploration of the impact of tapping the wire at various points could be added: the electrons have additional wires to pile up in, changing somewhat the outcome. It's not immediately obvious that this can be ignored.
There’s a methods video on the second channel if you’re interested
I've seen the "ringing"/"bouncing" oscillation effect on an oscilloscope when connecting wires before but to see it graphed out spatially like that is incredible
I didn’t REALLY understand it until I could see it spatially. This is one of those cases where figuring out how to make a visualization ends up teaching me
The impedance-matched version is WILD https://www.youtube.com/watch?v=RkAF3X6cJa4
@@tripplefives1402interesting
@@tripplefives1402 nice, thanks for that comment, it just clicked in my head for understanding antennas, totally makes sense after this video!
This is also a good explanation for Impulse reflectometry. . Next time, take a car battery as a power source, and then you dont need to measure in which branch the short circuit is.
Wow. Just wow.
As an electronics engineer I can say that without the shadow of a doubt this is the most easy to understand, visually impressive video about electricity I’ve ever seen - and the insane amount of work that this must have required just drips out of every pore.
And I have never actually thought about how the waves flow… this is insanely interesting! Thanks so much!
This was demonstrated in my high-school Vocational Tech Radio - TV Repair class using Tubes & dual trace oscilloscope. the effect described here has implications in pulse & wave shaping for mil-spec IC substitute and circuit cross-talk. I am solving an ELF (Extremely Low Frequency) innovation where this demonstration is one factor in the solution. PhDs can be a challenge for explanations. 😊
In the early '80s, I built a semiconductor company to manufacture semi and full custom analog and digital ICs. Our designs were in everything from toys to spacecraft. It must be so much easier/more-fun to learn now, than then. I'm obsolete as hell, but this was fun to watch.
@@EatMyOats Please make sure to upload a youtube video about your project once it's public! Thanks!
@@RickMcCargar In university a professor explained the concept of "software defined radio" to us. We were used to calculating antennas and frequencies and at first thought he must be joking.
Then showed us his gear: a room full of equipment worth hundreds of thousands.
Today I have one in a drawer somewhere, worth 150 EUR and the size of a box of cigars.
But to me, honestly, it still borders on black magic that this concept actually works.
In this circuit, the twisted pair functions as both a resistor and capacitor. The initial inrush current is taken up by the capacitance. When it reaches steady state, only the resistance is applicable.
You have essentially reinvented a time domain reflectometer (TDR). It uses the reflected pulse to determine the length of a wire. It can also determine the distance to a fault or splice (useful for locating a fault or determining that a signal cable has been tapped). The same principle works for fiber optics. For security purposes, an easily broken and nearly invisible unsheathed fiber is woven through a barrier. When the barrier is cut, the fiber is broken and the exact location of the break is determined by the TDR. Hint: Don't ever try to break into a Google data center.
That's exactly what they did when my glass fiber connection was broken. I didn't understand how the measurement tool worked. He explained it, but to me, it didn't make sense at the time.
Thanks for this. With this video and your comment, "reflectometer" becomes as easy to understand as echolocation.
So the ringing after the inrush spike is because of the stray capacitance and inductance forming a tank circuit right? Resonance at the natural frequency
DAMN! I was just about to mention the TDR. Navy avionics school, 1975.
So if I understand correctly, the initial reflection at the fork is caused by resistance(impedance?) change of doubling the wire cross section? If the forking wires were smaller and summed to the cross section of the initial wires there would be no reflection at the fork?
Reinvented TDR? You can go back further and explain why turning on an amp (audio or radio) without the (speaker/antenna) connected can destroy the equipment instantly! (ok, in a few nanoseconds, when that voltage inrush spike comes back!)
As an RF engineer, this is actually quite intuitive. When you flip the switch, the current rises rapidly, which can be seen as high-frequency signals (just look at a Fourier transform of a rectangular signal). These high-frequency AC signals travel as waves through the wire, which is why the voltage appears like a traveling wave. It would be very nice to repeated that experiment with purley high frequency AC signal source. Howevere the Equipent to do so is very expensive. Maybe Rohde & Schwaz or Keysight might be interessted in sponsoring something if you ask.
“In this video we’re actually going to be able to record this circuit fast enough to differentiate between these four options.”
What a Time to be alive!
the future is now old man
Can be done with ferrocell and photo camera, or by thermal imaging in multiple takes. The guy is complete idiot who don't know how current travels and how to use his oscilloscope to get real conclusions.
I am starting to become sick of these pseudoscience channels.
hold on to your papers
I've been a PCB designer for 17 years, some of my best training was a hands on hydraulics class that I took at a tech college. It's surprising how well the analogy holds up. I'm just an electron plumber. I love your video and really wish I'd seen something like it my first try through college physics.
Electron plumber!
Hope you don't mind if I steal that term as a fellow PCB designer! xD
Yes I was surprised when I read the difficulties of "ordinary" consumer USB cabling and how and why it's impossible to have long cables due to higher frequencies (signal quality, capacitance), connection reflections - all ending in tighter tolerances. High-end PCBs, chips are all that³. Cheers
@@VADemon Yup, thankfully there are fiber optics for when the need is great enough to justify the price.
What a cool visualization, huge props for tediously collecting all that data! Something about seeing the real data moving in waves like that is just _so awesome_!
there were multiple times I think i audibly gasped looking at graphs while working on this project. the first was the test animation for propagation, which was SO satisfying, but my favorite was actually the time I accidentally impedance matched the circuit on the table and finally understood - I'm disappointed I ended up relegating that bit to the second channel but I couldn't explain it without more math lol
by the way, your injector video was fantastic. I really want to try to make a liquid fuel engine one day
This took me back 10 years to physics I did at 18.
I remember my teacher presenting this on a much simpler demo circuit.
To his credit he was a great teacher and was able to expand on the limited demo with his explanations.
But this demo is so clear!
Awesome! As a 40+ year electronic technician I knew the answer, we just always accounted for this as an initial "spike" when energizing a circuit, sort of "filling the pipes" so to say. Your visuals really brought it home for this old "sparky".
Old Sparky, so when I was a kid way back, parent or grandparents would say, "Don't keep flipping the lights on and off, it uses more electricity!". Is that because the initial first few waves it does use more energy than needed before it settles in? Now once they told us this we did it many more times because that what kids do. But they were right!
I'm a mechanical tech and I understand the concept of inrush current.
This video was really good. I also deal with high pressure fluid circuits with dead sections that start and stop and this will be in back pocket from this day forward.
@@TUTruth The initial few waves don't matter much for power consumption. The reason they told this, is because the filaments in incandescent light bulbs change their resistance with temperature. When they're cold, the resistance is low and a high current flows. Once they heat up the resistance rises and the current drops. When you kept flipping the lights on and off, the filament didn't stay hot, so more current could flow
@@TUTruthFlipping the switch on and off actually uses less electricity overall. Light bulbs use a lot of power when you first turn them on because the resistance is very low at room temperature, then the filament heats up to maybe 2700 kelvin (almost immediately), resistance goes way up with temperature, and current goes down.
This is why you can't guess the watt rating of a light bulb by measuring the resistance with an ohmeter. Try it. Measure a 100W bulb. The resistance at room temperature will make you think the bulb will use 10x that amount of power, but this is only true for a fraction of a second.
The real reason to not flick the lights on and off is that it damages the bulb. Any time you've seen a bulb burn out, it was when you tried turning it on. They very rarely burn out while they are already on.
Also true for fluorescent lights. Striking the arc wears out the tube.
@@shawn576: Thank you. Excellently explained.
I'm a technical trainer who was wondering why an open circuit in a car's network system caused a huge voltage spike on the oscilloscope. This video single handedly demonstrated and proved what was going on and why. This was exactly what I was looking for - thanks so much!
CANBUS is super interesting stuff, I've spent many months studying it. This video re enforced to me how electronic networking is just voltage pulses of "information" sent down the line and detected. It's the same concept with how the battery "figures out" how much current to send down the line as it is in actual networking systems. Voltage is sent down the line and feedback is sent back.
@@kc7affsame with a process called "TCP windowing" in networking. The TCP tries to find a confortable medium between super fast data stream and dropped packets. (Source networking engineer)
Now I understand why my truck's poor electrical from past owners causes issues for me all the time. :)
This deserves a standing ovation. This should be required viewing at EE classes, enough said.
Amazing video! People like yourself making high quality videos of difficulot subjects is what makes Youtube invaluable.
The great thing about this channel is that it's not about fancy production values. Your technical skills and enthusiasm carry it all by themselves. Thank you for the effort!
I can hear Master Piandao going “it certainly wasn’t your skill” 😂
The bouncing and ringing are due to capacitance and inductance effects of the imperfect conductors. The two combined give you reactance, you measured it beautifully. This is also why we use termination resistors in data lines like RS485 at dead ends in order to avoid bouncing waves of signal causing interference.
It's not that the conductors are imperfect, it's that they exist at all; even a superconductor inherently has inductance and capacitance with the world around it, and a sole superconductor not in a transmission line would still deal with the characteristic impedance of free space. He's replaced the characteristic impedance of free space with the characteristic impedance of the twisted pair, but the dynamics are due to electromagnetic interactions of the current wave with itself, not resistance or imperfections in the line. It is the impedance mismatch at the end that causes the reflection.
For me it's easier to understand the behaviour of the disconnected wire considering the twisted pair forms a big capacitor. Huge voltage at first, as the capacitor is not charged. As it charges, voltage drops closer to zero. And all the resistances, inductances and capacitances make up effectively a RLC oscillator.
why such presentations an animations are not givento people in the school..?
@@MrMassmaker They are, we performed similar measurements at EE school to understand conductors better in real world applications. In my case it was a spool of wire that we characterized with a signal generator and an oscilloscope.
I'm a commercial service electrician, and this video has cleared up some VERY perplexing issues that I've run into in the past that were causing some sensitive electronics to act up. At the time I was able to "fix" the issue with luck, and trial and error but now I have a pretty good idea of what was happening.
You learn something new every day!
Can we know about what was the problem exactly and how you solved it? I am not an electrician but it sounds educational
I second @painlessskun3959 request :)
Seriously! Thank you for taking the time to plot so many points in that graph animation. That was so cool to watch and is a great way of seeing electricity
I have a physics bachelor's and i think this video should be shown in the first year. It really helps build an intuitive understanding of several concepts that I always struggled with until now. THANK YOU SO MUCH! It also begs for follow-on experiments such as demonstrating wire configurations with high versus low capacitance. I love that electron gas pressure propagation is so visible and that electron drift velocity is definitely NOT the same! This is inspirational experimental physics at its best capable of inspiring young enquiring minds to think about the phenomena in our daily world that we usually take for granted. SUBSCRIBED! And why do I discover this great channel only now?! All the best, Rob in Switzerland
A part of the effect of capacitance is shown in this video: https://youtu.be/9hhcUT947FI?t=631
Haha, welp, I'm a first year EE student studying in Switzerland right now 😅 very glad to have found this channel indeed, super inspiring stuff
This is beyond incredible. The amount of time you spent on something so ubiquitous and distilled it down to such an easily digestible morsel of information is absolutely brilliant. The animations were so fascinating to see, and I had chosen B for my answer, and when you showed the water flowing in the channels I nearly second guessed myself lol. Incredible work man, I look forward to your videos!
Could not agree more.
I also guessed B, but C was what I was picturing as I did. I think the wording was a bit confusing, as I was hedging toward B because it's a more physical description, where C is more anthropomorphized.
This is freaking great. The video itself does not show, but the amount of effort it must have taken to get all these measurememts.... great job, hope this gets some nice exposure, because this really clearly explains how electricity works.
This all had to take FOREVER to set up and refine
I sadly don't have a timelapse of taking all the measurements multiple times, but here's a video with a lot more detail on the setup! https://www.youtube.com/watch?v=sty0Y1qmgEY
Time to reach out to LeCroy and Keysight and get them to sponsor you with a many-channel scope 😂. But seriously, NI makes 12 and 24 channel “scope-DAQs”… 😊
This was the clearest example of electrical dynamics that I’ve seen on YouTube! Really helped me understand thank you
This has been an excellent series, I am an avionics technician, we have a lot of rules of thumb, do this don't do this, that keep our circuits working. But few can explain the underlying why's in a coherent way. For instance we terminate unused data busses with terminating resisters to stop "reflections", here I see exactly what it is that we are stopping, return waves that stomp all over our signal.
How do I become an avionics tech?
@@mrblank-zh1xy I did it by joining the Navy. I worked on the AWG-9 radar system for the F-14 from 2001 until it was decommissioned in 2006. I also cross-trained to the F/A-18's radar systems, the APG-65 and the APG-73. Free training, plus a GI bill on top of that. I also went to 2M school (miniature/microminiature electronics repair) to round it all out.
Is that a 1553 data bus you're talking about?
This is why the TDR (Time Domain Reflectometer) is so cool. It displays the "echo" of the electric pulse bouncing off the break. And that's how we used it in the telephone industry to find the distance to a cable break (or see the "bump" of a wiring closet on the way to the actual cable end elsewhere farther down the "circuit")
It doesn't just work with electrical signals. It works with optical signals too, although for shorter runs (like in planes rather than between neighborhoods) a frequency domain reflectometer, which doesn't rely on a pulse, but a constantly changing frequency, provides the necessary resolution.
What do you mean with shorter runs? In optics typical OTDR can measure fibre cable break distances 100 km or more easily. The longer the cable, the more time you have "to measure" but the more sensitive detector is needed.
I remember the wave of understanding when I was a kid and the guy that came to fix the phone explained how he could measure the distance to the break in the line.
Brilliant!
This animation, the setup, and the measurement must've taken a lot of time to get right. This level of patience is something I aspire to have after watching this incredibly enlightening video. You are my hero. Thank you, from the bottom of my heart! This video should be a must in all undergrad curriculums.
You're*@@My_Fair_Lady
@@AlphaPhoenixChannel lol
@@My_Fair_Lady
But... how would someone 𝘂𝗻successfully pull something off?
I have unsuccessfully pulled off so many stickers @@-danR
Undergrad EE entering her junior year here-- your videos are AMAZING. I'm a very visual thinker and therefore learner, which is not an advantage in this field lol, so I've always tried to think of EE concepts by relying on chemistry and emag fundamentals (allowing me to think on the molecular/subatomic level) but really needed an extra push from an expert. Unfortunately this was never going to come from my professors, since teaching EE at that level is (apparently?) unconventional-or maybe just time consuming. In any case, it's worth it because THIS and your intuitive approach video have been that push!! True physics gold, you'd make an awesome professor- thanks for what you do!
Fantastic video! I have a master's degree in EE and work as an RF/antenna engineer and this is probably the best demo I've seen of these EM concepts. Amazing job breaking it down in such a way that I think anyone could understand. There's definitely some really interesting and cool material in the transmission line and RF realm which builds fairly well off of this, I'd love to see your take on antennas (and selfishly think whatever demo you'd come up with would make it a LOT easier for me to explain my job to people lol).
A video on antennas would be very cool
Indeed... Even this DC circuit was AC for a little bit... RF is so fascinating. :)
Agreed! I felt pretty good figuring out which option was the right one but I can only attribute that to my knowledge gained from Amateur Radio and antenna propagation theory. I would be fascinated to see this on an antenna with RF signals but also to include actual electron flow as well. I've always thought of electron flow through wire as similar to water, but have always had a hard time equating that to RF in a wire. I would love to see it mapped out like this and the two compared. Totally geeking out right now.
I am an rf tech and I suspect that brief moment of current starting through the circuit on the open branch the energy radiates. Looks like a dipole antenna. I paused the video before finding out the solution. I have done this thought experiment with millions of miles of open pathway on a circuit. How in the heck does the circuit know it’s a dead end without violating Einstein’s theory that no disturbance can go faster than the speed of light? From another perspective, the time factor may help explain why energy has to radiate from an antenna in the first place.
@@artofplanets Because Einstein is NOT the END-ALL definitive source, or Law Maker. The Universe is. And Laws can change when the environs reach states we dont ever (or hardly ever) experience, percieve, or theorize about. And even then, we dont always predict events with 100% accuracy in these areas.
Short answer: EINSTEIN was wrong, and he even admitted it, if you look hard enough youll find it out there. The SPEED of LIGHT is NOT-EQUIVALENT to the Universe's "Speed LIMIT". There is no TRUE "Limiter" of Speed Full-Stop. Theres only changes of existent forces due to the current 'moment' and its environment/medium/surrounds. And that leaves A LOT of variation, some of which we still cant actually test for.
When you said "and then I spent hours stripping wire at hundreds of locations to attach the probe clips" I rolled my eyes and thought whyy?!. But your determination to follow through is what makes this so special! Brilliant combination of experimentation, video, narration, and the data-driven animations... really impressive.
After teaching basic electricity for 35 years or more this is the best explanation and visualization that I have seen regarding current and current flow and how the wire bunches up its electrons and releases them quickly or slowly and remember 6.25 million million million electrons flowing through a wire in one second equals 1 A so electricity is it all that magic you can actually see it and measure it
I remember doing this exact experiment in Physics class in 1977 when I was in 11th grade. We compared and contrasted water waves with electric current over time and determined the speed of the electrons as shown on a primitive oscilloscope (about five times the size of a modern one). I am glad to see that there are those that are regaining the knowledge nowadays...
This is my 1st introduction to your work. You make it fun to learn, and cover all the variables. You should be a teacher. Thanks for making my morning.
This is the most complete explanation of wave propagation and line impedance concepts I ever saw so far. The idea is sooo cool. And yeah, I feel the same way regarding availability of relatively cheap devices that allows for literally light speed measurements on a bench. What a time to be alive.
@AlphaPhoenixChannel - 2023-12-06
Corrections and FAQ in this comment!
Check out the other channel for follow up videos, and video Q&A that I'll be posting in a few weeks with questions from here and from Patreon! https://www.youtube.com/@AlphaPhoenix2
Check out the Patron page if you want to support the channel, get early access to videos, and join us on Discord! https://www.patreon.com/AlphaPhoenix
Thanks to @ElectroBOOM for giving me a sanity check on this data a few months ago! (I hope you like the final video)
FAQ:
0) Questions about the experimental setup (including the effect of the probes on the circuit while I was measuring) are here! https://www.youtube.com/watch?v=sty0Y1qmgEYc If anybody wants to recreate this project, or turn it into an undergrad physics lab. hopefully there's plenty of info there! If I can remember how to use github I'll post some of my visualization code and leave a link on that video.
1) Lots of commenters have that I'm confusing voltage and current at times, but I tried to be very careful with my language. Current is the actual motion of the electrons, and in the graphic I showed with the blue dots moving around, I'm calculating that motion based on the voltage. it's basically the current that is NECESSARY to produce those voltage patterns. I also did a measurement where I measured the current directly by placing a very small resistor at the input lines and measuring the voltage drop across it over time, so I know my calculation lines up vaguely with that, but it WAS only a measurement at one point. If somebody wants to put a quarter ohm resistor every 4 feet along a wire and measure more voltages, I'd LOVE to see the data! I'll talk about the script a bit more in the Q&A video that hopefully will be out in a few weeks!
2) When you first flip the switch, the battery doesn't actually see a "dead short". The current out of the battery initially is limited by the line impedance, which depends on the properties and dimensions of the cable. In this case, it's the same current you'd get by bridging the switch with a 150 ohm resistor!
3) A lot of people have questioned the use of the words "communicate" and "sending information". I admit I anthropomorphize a bit too much in this video, but particles and groups of particles "communicating" and the rate at which "information" can move are very important hard physics terms that don't imply the particles are thinking. "Information" here consists of things like partical position, and they pass this information between each other using the electric field.
4) Water is a compressible fluid. if water wasn't a compressible fluid than pressure wouldn't work and water wouldn't be able to flow around corners in pipes. The way I'm using it it's actually EXTREMELY compressible (in the lateral) direction because it's allowed to expand upwards without getting significantly denser. Electrons in a wire are orders of magnitude less compressible than water, but it's still worthwhile to think of them bunching up!
5) ...........keep the comments coming! i spent like 4 hours reading comments yesterday lol
@JustSOMETHIN-v1y - 2023-12-06
The correct answer should be 'B'. Recently(I mean 6 months ago...) I saw the debate of Veritasium and electroboom and came up to that conclusion...
@roustache - 2023-12-06
I have a question, in your exemple with the open circuit we see the fact that the electron are closer in one wire. what happen when you stop the batterie ? (open the interuptor in your case) does the potential rest in the wire ? making it a small capacitor ?
@AlphaPhoenixChannel - 2023-12-06
@@JustSOMETHIN-v1yI actually emailed some early data from this experiment to Medhi a few months ago and he said it was cool 😊. I’m not trying to “prove” or “discover”, anything here, just demonstrate. Electricity is very well understood by humans, it’s just hard to explain.
@JustSOMETHIN-v1y - 2023-12-06
@@AlphaPhoenixChannel I cannot believe that you actually replied! Thank you very much!
THIS IS GREATLY APPERICIATED! 😊
@XIIchiron78 - 2023-12-06
@@JustSOMETHIN-v1ythat Veritasium video is pretty misleading. There would be some detectable trace effects due to the fields being in proximity but the full voltage only arrives later as you would intuitively expect.