Why does WATER change the speed of electricity?

The electrons are back! This is the first of three videos discussing electricity - what is it, how does it work, how do we use it? This first installment talks about the speed of electricity and electrical signals in wires. Next up is Ohm's law, and what resistance really does in circuits, and third, I'll be taking another look at the experiment featured on Veritasium last year, building on the first two videos to explore the mechanism that couples the two long wires with a little more scrutiny. Enjoy!
Be sure to check out the subreddit:
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Music in this video:
I Dunno by grapes is licensed under a Creative Commons Attribution license (creativecommons.org/licenses/...) ccmixter.org/files/grapes/16626

[@AlphaPhoenixChannel]

Corrections and FAQ answers: 1) "When are the others coming out?" I planned to release all three of these videos on adjacent weeks, but the other two aren't done yet, and I wanted to release this one sooner to give the algorithm a kick in support of my last video from just a few days ago about FIRST Robotics - go check it out! kzbin.info/www/bejne/eKrGooqPeph0n9U 2) Pre-emptive clarification about the overly-philosophical ending: Sine waves are not the only orthogonal basis set that can be used to construct any function, so you could argue that any similar construction is arbitrary and math-only, and would STILL be indistinguishable from reality. That said, sine waves are really pretty (and can actually be used to solve equations that demonstrate propagation). 3) Microwaves! I've had a bunch of people ask about the "resonant frequency" of the water molecules (or any dielectric). This is exactly how your microwave works, and at this frequency (2.4 GHz I believe), the energy transfer from the field to the water molecule is most efficient. 4) What's the difference between this and coax, and velocity factor? In coax, the entire field is contained between the core and sheath, so the cable designer has COMPLETE control over the speed of propagation in the cable by choosing the dielectric insulation that the field has to pass through. This experiment I've set up is REALLY terrible at making sure the field has to interact with the water. There's probably a lot of "field leakage" I'm not dealing with. coax is amazing in it's ability to be controlled and uniform. 5) The frequency of flipping a switch: in the absolute most hand-wavey way possible if we assume that the ~40 nanosecond rise time for the signal (switch flip) is actually 1/4 of a sine wave (as in cut out of a wave, i said hand-wavey), then the relevant frequency would be ~6 MHz. In reality this is probably within an order-of-magnitude, but many additional frequencies are needed to reconstruct the exact shape of that rise, and I don't have a great intuition for which ones carry the most energy. 6) I did perform a "zero length" measurement to confirm that the scope channels were synchronized and the "send" and "receive" signals rise at the same time. I don't remember the offsets I measured right now, but they were much smaller than other errors in the system, like measuring the length of the wire! 7) I didn't realize at first that the pipe was at a bit of a slant, so the end the camera was looking at was only part full when the wire at the other end was already submerged. I don't even want to think about the weird physics problem of having water ADJACENT to a wire and trying to predict anything, so I only talked about the "empty" and "full" configurations. 8) ???

[@hobbyjoytv4530]

Where’s that part 2 u promised? I had the impression that you cut off the rest of the footage recorded for your previous vid on electricity and was making that into another video

[@AlphaPhoenixChannel]

@@hobbyjoytv4530 part 2 is now three parts lol. This is part 2a

[@AlphaPhoenixChannel]

@Primarch290 that’s actually much slower because it depends on the average refractive index of the glass en.m.wikipedia.org/wiki/Fiber-optic_cable (edit, deleted their longer angry second comment because it had no place in this base thread)

[@RIGeek.]

You need to try this with different velocity factor coax.

[@Kenionatus]

3) ??? 4) understanding

[@Martmists]

Have you considered making a video on how oscilloscopes work? While the core concept may be simple, any software developer knows it's ridiculous to measure something smaller than a nanosecond, let alone record events for _longer_ periods of time and filtering it to .1 of a nanosecond.

[@DanKaschel]

@@DehimVerveen I think this illustrates the utility of that kind of video. As a software developer, this leads to more questions -- e.g. even with an instrument capable of changing measurable state at that rate, how would you measure that state and record it at that resolution? Even with a fast processor (multiple ghz), we have just a few cycles to measure AND store--and we need to do so without immediately overwhelming whatever buffer is used. My intuition tells me that I'm thinking about it the wrong way -- that we're not just recording and storing all these data points but rather pushing all data through a low latency buffer and then copying that buffer when an event is triggered and these buffer copies are really the data being captured. But I really don't know.

[@jakubjendryka4554]

@@DanKaschel Your intuition is actually on the right track. During most of the data acquisition process no CPU is actually involved. When the oscilloscope is waiting for a trigger, ADC is running constantly, and data from it is saved directly to DRAM memory. The whole process is controlled using combinatorial logic inside an FPGA. Data is constantly overwritten in a circular buffer. When trigger is detected, FPGA continues acquisition for set amount of time, and then stops overwriting the data. Now the data can be read and processed in not-realtime fashion.

[@NeatNit]

@Daniel Kaschel I think your questions are mostly coming from a thinking like a software developer. You are imagining that there is a central processing unit (CPU) that needs to process the data in software, and this creates an obvious bottleneck as every piece of that torrent of data needs to go through that one CPU. The answer is that this isn't how it's done! Nearly all of the operations - acquisition, processing, storage, and display - are happening *in hardware* in some kind of pipeline. There is no software involved, and so everything happens in parallel. Think of it like a manufacturing line in a factory. One bit of data enters the first stage of processing, is processed, and then is sent to the second stage. While the second stage is processing that same piece of data, the first stage is now free to process the next piece of data - and that's what it does! On each clock cycle, all of these different stages of processing are happening *at the same time*, each one working on a different part of the signal that was captured at a slightly different time. At the end of the pipeline the processed data is dumped into some memory (overwriting the previous data), where a more traditional software computer is probably in charge of prettying it up and displaying it to the user. This software and user interface can also control the configuration of the pipeline - for example, change the sampling rate, or disable some optional part of the processing (like the Fourier transform). I hope that was understandable for you! Edit: keep in mind that even in a traditional software environment, there is a lot of work happening in hardware outside of the CPU - for example, generating the signal that is sent to the display. This idea of off-loading a lot of work that can be done in parallel is exactly what a GPU (Graphical Processing Unit) is for. GPUs are excellent at doing things in parallel unlike a CPU, but even they have to run in software and won't be as fast as hardware that was engineered specifically for one singular task - such as the hardware of an oscilloscope.

[@DehimVerveen]

@@DanKaschel Yes, like Jakub Jendryka said, your intuition is on the right track. What I would probably do is write the (possibly downsampled) ADC data to a DRAM buffer, while checking for trigger conditions in hardware. If a trigger condition were to occur, I would first write the remaining samples in the window to the buffer and then trigger an interrupt. The CPU can then read the data and do (optional) further processing, which may or may not be done with different hardware modules. The final processed data can then be displayed.

[@descuddlebat]

I'm certainly struggling to imagine how storing digital data without a CPU involved works, personally, I understand ADC conversion is instantaneous but the writes elude me

[@nepdisc3722]

For so much of my life I've just seen electricity as inexplicable magic that only people who dedicate years and years of studying to it can ever come close to understanding, but these videos are so elucidating that I actually feel like I'm finally starting to grasp the concept and that's HUGE. Thanks for doing all of this, it's fascinating to see.

[@AlphaPhoenixChannel]

I’m thrilled to read this! I’d much rather demystify something than make it sound awesome but inexplicable

[@nepdisc3722]

@@AlphaPhoenixChannel the oversimplification of thinking of electricity as one would think of water flowing through a pipe is what has given me the largest amount of trouble. It seems counterintuitive that if you have a protected/insulated wire that the electric field would be able to affect what's happening in the wire. It actually makes me wonder if maybe there could be a way to make a "slower" wire by just pulsing electricity through a large copper pipe/tube which would theoretically give the electrons room to actually bunch up together a tiny bit.

[@NeatNit]

@AlphaPhoenix, I'm sure you don't need me saying this, but this is the best kind of comment by the best kind of viewer. I am an electrical engineering student and I enjoy watching your EE videos, I'm even learning new things! I'm sure a big chunk of your viewers are in a similar place - we already know the basics, we just want to see the cool stuff. DON'T YOU DARE change your videos/style for viewers like me!! There is so much more value in opening up this world to brand new people. Not to mention even the experienced people often need refreshers on the basics! I just wanted to reiterate that. Those of us that don't need the basics can either skip those parts of the videos or just not stay super focused as you explain them. It can be entire videos, too. We are perfectly happy to stand by and help you welcome brand new people to the world of whatever-topic-each-video-is-about.

[@nepdisc3722]

@@NeatNit Even the absolute basics, when presented well and by someone who's clearly knowledgeable on the subject, can be very entertaining.

[@graealex]

The interesting part is that many people working in that field don't actually have a clue how electricity works on a quantum level. The closest many people in the field come to understanding it is when they go into microwaves (not the appliance, the frequency), as then electricity exhibits a lot more wave-behavior. It's basically a black art.

[@Geopholus]

You are one of the very very few people who do technical videos on electronics/physics, who actually have an excellent understanding of electronics, and manage to describe it simply and accurately!

[@jeffmatson2046]

True , in words of wisdoms .💪

[@yazmeliayzol624]

Unlike that Derek guy...

[@theethicsofliberty4642]

That's right ... The real secret of electricity is in the magnetic field ...

[@HolahkuTaigiTWFormosanDiplomat]

０．０

[@jadewombat]

Veritasium does some excellent videos on the speed of electricity as well.

[@scarletevans4474]

I watched Veritasium vs Electroboom's back and forth videos debate about this matter and, in my opinion, I have to say that you explained how the electricity works even simpler and better than them! Thank you for this video! ♥

[@bertblankenstein3738]

I find that Veritasium tries to be controversial when there is no need.

[@jyothishkumar3098]

​@@bertblankenstein3738 His controversy is exactly what got everyone thinking about it.. If he had just made a normal video, no one would've paid this much attention to it and we wouldn't have gotten AlphaPhoenix's data.

[@bakedbeings]

⁠@@bertblankenstein3738He definitely goes for the significant discovery/revelation vibe every time, and they don't come along too often.

[@timothymartin2137]

REALLY

[@skylerlehmkuhl135]

While watching the bit about how the different frequency components would "smear" the signal, I found myself wondering if the same would happen with visible light - and then realized that's exactly how a prism turns white light into rainbows.

[@pirojfmifhghek566]

And that's how we invented fig. Newtons.

[@ForboJack]

So a prism is a real life Fourier transformation?

[@AlphaPhoenixChannel]

@@ForboJack you can also do spatial fourier transforms with optics and it's pretty incredible. If i remember right there's an Applied Science video about it (yep, found it kzbin.info/www/bejne/rZS1c2aKjK50jqc)

[@ForboJack]

@@AlphaPhoenixChannel Very interesting. Thanks for the link.

[@DrummerRF]

@@ForboJack not really but apertures are :)

[@Wisterson]

As a licensed electrician. This is they type of content that keeps me safe and educated. So thankful for your hard work and enthusiasm.

[@deang5622]

As a degree qualified electrical engineer, it doesn't keep me educated ...

[@jeffmatson2046]

Excellent ,professional thoughts is always welcomed in science of thrills of learning .

[@steves.6649]

Gosh, this is why YT can get people back into the stone age.

[@MegaChickenPunch]

@@steves.6649 what?

[@TantalumPolytope]

@@steves.6649 explain

[@ronhensley2402]

I truly enjoyed this video! Thank you!!! I could have benefited greatly from this video 40+ years ago during my EE undergraduate learning. You did a great job of integrating a number of concepts that were compartmentalized in different courses. At the time, I really struggled with how it was all supposed to come together in a meaningful and practical way. FFT, Maxwell’s equations, micro field interactions, electrons moving vs fields interacting, partials and waves, etc etc etc.

[@radar_x8613]

The equation for propagation delay you showed only applies to EM waves is an isotropic media - like free space or within a single dielectric. Whereas the wire in the tube of water has water surrounding the outside of the wire thus impacting the external EM field but there are E-fields still within the wire (not even accounting for frequency-dependent skin depth effects) and these are still propagating near speed 'c' which is why the overall speed of signal propagation only slightly decreased by the submerged wire. Excellent video by the way. BTW, this comment is from an RF engineer.

[@VisualElectric_]

This is a very interesting experiment. I recently did a video on the first frequency dependent transmission line models developed to explain behaviour of first the transatlantic telegraph cable in the 19th century - it took several minutes to send a few messages because the line was surrounded by water, giving a huge capacitance. The background theory is fascinating.

[@TheAnoniemo]

Just watched the video you are talking about and subbed to your channel, can recommend to others to check it out too.

[@fisk7aal]

I think Heaviside introduced load coils to counter the problem

[@c0d3m0nky]

It's been almost a yr since the Veritasium video and we're still squeezing great content out of the "controversy", I love it

[@dieSpinnt]

Otherwise the saying "No shit, Sherlock", would die out, Alberto ... Or "beating the dead horse". What one do you like more? Hehe

[@WarttHog]

Totally! I feel like @AlphaPhoenix joined the battle, but when it appeared to be over, instead of going home like everyone else, he wrestled with reality itself until he'd transcends a few plains of existence! My brain nearly melted when the ideas of electric switches, Fourier transforms end prisms collided to explain why the rising edge gets smeared! Suuuuuuper cool!!

[@pyropulseIXXI]

There is no controversy, just morons that don't know anything. What Veritasium said is taught in every basic physics course in electromagnetics. It is in virtually every textbook on EM Light is an electromagnetic wave; wtf is electricity? It is an electric field propagating; that is an EM wave; electricity is literally light. Stuff isn't hard to understand; people are just really dumb and like to hold onto that feeling of being incredibly dumb while thinking they are smart

[@GLUKOVICH]

oh i so hate the Veritasium video...

[@wayneyadams]

What controversy are you talking about?

[@pasixty6510]

Well done! Your experiments are very helpful to understand the physics of signal lines. A big thumb up. I‘m looking forward to watching your upcoming videos.

[@benrex7775]

I've known many of the basics of what you said. But the way you brought the Maxwell into the question of electron movement and how that is frequency dependent was new to me. Thanks for telling me something new.

[@dennyoconnor8680]

As a Ham Radio guy I find your tests fun - and confirm what I have found in 60 years of playing with antennas. Your wire with thick insulation will have a Velocity Factor decrease of roughly 1% compared to a bare wire. I (we hams) see this in building antennas that are resonant at a specific frequency and using different wire insulation types. Wire thickness does have more effect on Q (which affects the bandwidth of resonance) than on Velocity Factor, but it is not in-your-face apparent. And your wire in a pipe demonstrates that the velocity factor of a coaxial feedline is highly dependent on the insulation and will generally have a velocity factor of 65% to 85%. Cheers, eh wot. DOC - K8DO

[@leoyru.3361]

you mean that if he make this test with coaxial cable the signal will travel at 65-85% of light speed ? . its a good idea for him to repeat the test with coaxial

[@tedmoss]

Right. WA7VQR.😁

[@dragonslayerslayerdragon5077]

Insulation is also an "observer."

[@COSMACELF1802]

Yeah, nothing new, but it's fun to watch just the same.

[@fno8205]

insulation changes capacitance. seen it too.

[@nick16693]

I really enjoy thinking "with" you. Thanks for the slightly personal yet really scientific way of directing your videos. You're really able to let me immerse in the experiment with you. Can't wait for the next episode!

[@danlscan]

You've managed to explain to me why some phenomena happen only with AC or DC and why some properties of AC are frequency dependent. Very good stuff for a technician to tuck away and digest. Thanks!

[@mattlong4102]

Bravo sir! Wonderful work. Amazing correspondence with lambda. Fantastic video in concept and execution. Simplicity was key here and I think you nailed it.

[@randomelectronicsanddispla1765]

The difference in speed is actually quite significant when you start tunning oscillating circuits and antennae. Transmission lines have up to 50% in speed difference It might be worth doing the same test with a piece of coax cable.

[@gammaleader96]

I wanted to suggest the same thing, with different types of coax having velocity factors from 66% to 87%, they should have quite a drastic effect.

[@lawrencejob]

I was thinking this because the outer reflector would have a really interesting effect on the magnetic signature. I’d also be interested to see other wire designs/shieldings to see how and why they affect it

[@jimwithheld7217]

As others have said, a common Coax has a 66% Velocity Factor. So a wire in a water hose is somewhat exactly one of those: a coax wire, so might expect something much the same as a measurement. If cutting a length of coax as part of a radio antenna or tuning circuit, the VF needs to be allowed for in the wavelength. So e.g. a 2m wavelength in a common ham radio band is not 2m, once you allow for the 0.66 VF correction.

[@wombatillo]

He's basically experimenting with free wires. They're difficult to control and characterize. HAMs know them well but in rf engineering they're avoided. He needs to submerge the wire in a swimming pool to get the nearly full effects of water's dielectric effects. Having a couple inches of water and feet of air is always going to get you only a fractional change. He basically needs to make a long pipe into a large diameter coaxial conductor, fill it with distilled water and observe a massive em wave speed slowdown.

[@maxbauer1633]

Audio Hifi: if the dielectric around a wire is able to significantly slow down lower frequencies even more so than high frequencies such as light, what about bass in music lets say 30Hz AC. ? some hifi enthusiasts swear by some ridiculous tricks supposed to improve audio quality , such as elevating loudspeaker wires up from the ground, they claim it sounds "airier" or "faster" i used to cringe at such descriptions now i am not so sure anymore. Could the ground act as a strong dielectric around a wire essentially slowing down the signal compared to wire being 50cm suspended in air above ground? what would be the time differences for a low frequency 30Hz AC signal? would the difference approach the miliseconds range and possibly even be audible?

[@dking7985]

This is another great video from your channel! One suggestion that I'd like your opinion on is that at 10:36 you showed an electron with its field lines moving out from the electron at the speed of light, I think an interesting alternative way to illustrate/animate this would be to show the electron at rest with the field lines already present and when the electron moves this creates a "kink/curve" in the field lines and the "kink/curves" themselves propagate at C. I'm sue animating these videos in difficult and time consuming beyond my comprehension but I was just wondering if my mental picture made sense to you. Thanks for the great content!

[@micahlanghammer3022]

i love your videos and the way you teach so much. the way you play things out and the visuals are just so great!

[@petevenuti7355]

Finding out that many of the equations I had to memorize in college were derived for specific cases and never being told what those cases are and never learning how to derive for other cases on my own really makes me feel completely gipped by college

[@jaewok5G]

there was an early day in an early class where we are first told the phrase "under ideal circumstances and conditions" and over time it becomes as invisible as air until we see it. I was lucky to have a prof who shocked me out of my trance when he was reducing an expression with a π in the denominator, spotted a '4,' proclaimed that "you'll never get these consistent values anyway," and just cancelled them. before that, I had considered π as sacred.

[@YodaWhat]

@@jaewok5G- That kind of approximation is why it *worked* to design the Saturn 5 moon rocket with only 3 or 4 digit accuracy possible with *SLIDE RULES.* _Spherical chickens, anyone?_

[@jaewok5G]

@@YodaWhat sometimes π was 3

[@boltez6507]

Thats actually quite important a good teacher/professor would always list the specific set of conditions for any specific equation.

[@boltez6507]

@@jaewok5G e=π=3 😂

[@dougcox835]

Not a quibble, just a tip. Your scope was mistriggering a lot and it took me a minute to see why. You had the trigger level way near the top of the signal. Just move it down to somewhere in the middle where it's less noisy and very distinct. Take advantage of that sharp rise time.

[@Jezee213]

Just subbed to the channel, I love all the experiments and topics. Keep up the awesome work man.

[@davidatrakchi2707]

Thank you for presenting this in such a nice way, and, your enthusiasm is catching!!

[@eikeschwarzwald6799]

This is such a wonderful series. I'm so glad, that the "flame war" produced something with such a scientific precision :D This is not just the V-style clickbait stuff

[@vogelvogeltje]

Veritasium joke?

[@eikeschwarzwald6799]

@@vogelvogeltje nah, Vogel-joke hrrhrr

[@eikeschwarzwald6799]

@@vogelvogeltje sorry, had to...

[@tedmoss]

Rather a popularization of it, not clickbait.

[@gingermany6223]

So many good analogies to light here (which makes perfect sense really). Adding a pinhole to a light path doesn’t slow down the light anymore than increasing the resistance of a wire slows down a signal.

[@dieSpinnt]

Yeah, in other words: Electromagnetic Waves have analogies with Electromagnetic Waves. ... no shit, Sherlock! **facepalm**

[@gingermany6223]

@@dieSpinnt That's why I added "which makes perfect sense really" but I guess you missed that? 🤷‍♀ Also, sorry you don't know how emojis work.🤦‍♀

[@user-carlthomas]

O hell yeah! I am so happy to see guys doing fundamental research...ie..research on fundamental issues.. Veritasiums electricity piece was excellent. Im very positive this is gonna be great ! Thx !!!

[@TerryMundy]

This is the first time I've watched your video. Very easy to understand the way you explain the content. I subscribed!

[@randomelectronicsanddispla1765]

Actually, flipping a switch, from an electronic engineering point of view, is very much high frequency. The faster the fall/rise time, the higher the frequency. Cue the importance of dielectric materials in circuit boards in computers, phones,... This video could have so many tangents... The atoms and molecules aligning to the field are what Nuclear magnetic resonance and medical MRI rely on

[@Michaelonyoutub]

I was thinking about microwaves when he was talking about realigning the molecules to the fields, as that is essentially what a microwave does. It is insane how much we are able to do with such a simple principle of polar molecules aligning with magnetic fields.

[@wombatillo]

Yeah but NMR uses +1 Tesla fields to mess with the atoms basic state and thwe actual reading of the data is done with rf sweeps and pulses. Nothing like that is happening here. Dielectric heating works just fine at surprisingly low frequencies. The tuber really needs to understand the fundamentals of em field theory and circuit theory first.

[@cortexa100]

This is exactly the angle i expected. I think he took more of a physics approach followed by AES with the signal decomposition.

[@robertoverbeeke865]

@@wombatillo Maybe for your vocabulary. I was allowed to draw and make music in high school and skip physics and math. Give me a minute with this awesome teacher before i call him a tuber that don`t know em field theory. 1 question though. Is about measurements on a line vs a loop, loop making a field? be gentle!

[@robertoverbeeke865]

one more question about speed. circle vs square. does that make a difference?

[@schuwi4]

I study electrical engineering but I've always had a knack for every aspect of physics and understanding how it works at a more fundamental level. I am always amazed at how well you can explain all these concepts you show in your videos and always manage to answer exactly the questions I would have had. Thank you so much for spending the time and effort of producing these videos for us and keep on learning new interesting stuff!

[@jeffmatson2046]

That's so good . Teach beyond yr limits.

[@maxbauer1633]

Audio Hifi: if the dielectric around a wire is able to significantly slow down lower frequencies even more so than high frequencies such as light, what about bass in music lets say 30Hz AC. ? some hifi enthusiasts swear by some ridiculous tricks supposed to improve audio quality , such as elevating loudspeaker wires up from the ground, they claim it sounds "airier" or "faster" i used to cringe at such descriptions now i am not so sure anymore. Could the ground act as a strong dielectric around a wire essentially slowing down the signal compared to wire being 50cm suspended in air above ground? what would be the time differences for a low frequency 30Hz AC signal? would the difference approach the miliseconds range and possibly even be audible?

[@JoachimVampire]

see? this is the kind of simple explanation we all need. haven't seen any videos prior to this except for one a few months ago that talked about magnetic fields and it stated it was lightspeed (not almost) and it didn't have any kind of measurement, just a simple light that turned on on a press of a switch... it was was overlycomplicating every single step. today i randomly found this and it's really nice.

[@Jai_Lopez]

Dude everything you were saying when you was explaining it I was like also expecting you to say what you were saying almost as if I was narrating what you were saying or going to say practically being on the same page understanding the science of physics, great video great explanation. At marker 11:01 i had the idea for a follow up on this video, you should make a video demonstrating visually a set up experiment where we can see their electric magnetic fields being generated and or reciprocating by the following electrons on the wire into a chronological order of distribution across it.

[@redshifted8790]

My brother in MSE, talking about spinny water molecules at different frequencys is significantly less abstract than all the electrical engineering and physics before. All of wich was excellently explained though! I would also like to appreciate how diligently you not only perform and explain your experiments, but how you also try to find flaws in them. True science stuff.

[@1magnit]

It's all about capacitance. You're changing the CR time constant.

[@ZegaracRobert]

@@1magnit Kinda (simplistic) but it's bit more complex...

[@etimacias]

Just one note on the scope you used - for measuring, use a single connection to either ch 1/2 and a single one on ch3/4, as if you connect 2 signals to one "pair," (i.e. 1 and 2) it decreases the effective BW to 500MSa/s from 1GSa/s - it should result in a cleaner output and easier measurements :)

[@tomscum61]

New subscriber. Brilliant exploration. The genuine enthusiasm is great. You have a rare skill, thank you. I generally listen to KZbin at 2x speed. Even at 1.5x , I had to pay attention.

[@robertallen5890]

I really like your way of explaining the flow of electricity and the experiment you used along with your clear speech that's easy to understand but unfortunately there are still some terminology I was not familiar with but thanks for sharing.

[@kerryhaycock9446]

Nice work and great communication . This channel is getting toward that point of rapid increase in subscribers and well deserved . The bigger science channels have started to mention your work more I’ve noticed so you are gaining considerable respect out there …. Let’s see if Derek , Dave , Steve Mould and Mehdi quote this one …

[@leonhardtkristensen4093]

I think Derek could learn from this one. I actually think he should.

[@GaryFerrao]

That oscilloscope is a really nice tool. Now that you effectively described propagation delays, i marvel at the construction of that oscilloscope.

[@garfieldnate]

I would love a discussion of "the skin effect". How much of the electron fields extend into the surroundings of the wire vs into the center of the wire? Could using a larger wire reduce the effect of the water, since more of the signal could pass through the center of the wire itself instead of the surroundings?

[@jimmangefrida5207]

I'm not sure if this video was inspired by veritasium, but I have to say I think you did a great job explaining it, and went much further in tying the concepts to reality.

[@austinwolfe7295]

Your videos drive a deep inner curiosity in me. The curiosity I remember always feeling as a kid. You've helped drive me to further my education and I just signed up for some supporting classes I will need for mechanical engineering. Keep doing what you do! This kind of video motivates the heck out of me!

[@adamrak7560]

You really should try to build your own coax cable, like a metal pipe with a thin wire within. (and use a differential signal between these two) That way the fields are confined and you have more control over them. You might get more slowdown from water this way too, because the entire field would be confined in the water.

[@OrbitalCookie]

@AlphaPhoenix Yeah, this also ties it in to the real world - why do the coax cables are made this way. Also I think one practical thing that wasn't ever mentioned was Ethernet cables, containing multiple pairs of twisted wires, and CAT-6 standard, where there is a X-shaped plastic separating 4 pairs. This helps to better tie-in to the real world and show people that these aren't some esoteric things, but the reality that the engineers are already dealing with.

[@KurtBlanken]

​@@OrbitalCookie The spline isn't part of the CAT-6 standard, but it's easier to meet the standard with one so that's what nearly all CAT-6 cables have. Many CAT-5e cables are also splined.

[@RBBlackstone]

Great video. Testing well is not easy and you nailed the details. I am curious what happens if you add salt to the water, making it conductive. Also wonder what changes if you close the loop so the field couples. Thinking twisted pair here. Thanks!

[@craig933]

Something fun (that you might have already thought about) - on Tek scopes you can save waveforms and display them alongside the live-view mode. Not positive if siglent scopes have similar functionality, but I feel like we might end up seeing some interesting changes to slew rate or debouncing, maybe some different filtering effects?

[@Bebeu4300]

Fantastic video! It explains everything very well and demonstrates what you're claiming. I also appreciate the use of only SI units.

[@h7opolo]

thanks for redoing this experiment with more attention to detail and accuracy.

[@ronanlyons5525]

It's amazing the natural fundamentals I learn from your videos

[@andrewberg146]

I appreciate the accuracy of using the molecular orbital density function to show electrons on the water molecule. Thanks.

[@enderknight1048]

This is actually interesting… keep up the good work! Love the content!

[@semanticks]

You are my favorite nerd on the internet, every video is like a science fair presentation thank you for making these wacky and educational contents. I hope you are doing well out there :)

[@CousinBumbleF]

Dave Jones gave us a very topical lesson on a.c. vs d.c. propagation many many years ago. Day after watching Dave’s lecture I installed a huge amount of new cameras at a very large storage facility with my new boss… at the time. Being young and dumb noticed he specified d.c. power supplies; I then confidently stated the cameras at the end of facility won’t work with d.c. Long story long, I ended up installing a.c cameras late at night on a wet, freezing day, hours from home. Just wanted to say thank you for making informing videos as they do have a real impact on every day situation. P.S I was thinking of the applicability on transatlantic stock market cables.

[@mrcrunch8000]

The explanations here are amazing. My first video here and I'm hooked. Thank you

[@wolframstahl1263]

This opened my eyes to a few ideas that make my understanding quite a bit weirder. What we're doing here is basically observing the speed of causality for a certain phenomenon, and we learned that this speed is dependendent on frequency and on the medium, basically its refractive index. The thing about the refractive index I remember from uni is, it's not just a single number like I learned in school, it's a frequency dependent complex 3x3 tensor. That means, in unisotropic materials the speed of causality also depends on direction, which is a neat and mostly useless detail that I thoroughly enjoy.

[@dieSpinnt]

With (media-)parameters x at time t we measure an effective field propagation speed of y with t to t'. WhyTF should the behaviour of y change ? Or causality? (Hint: They DON'T!). Changing x leads (possibly) to a change of the outcome ... what a trivial realization. Also in a relativistic view and in YOUR inertial system there are NO velocities that you can observe from the "outside". If you think you can be such an observer("speed of causality", LOL), no offense, you should see a doctor!;) By the way: cause and effect can be classified as at point t0 and t1 in time, if you like. But wanting to glue SI units/dimensions to a term that describes the logical relationship between cause and effect is the dumbest thing I've ever seen. And it started so well ... all is very easy and observable. Kindergarden stuff. Only a Glass of water or a Prism is needed ... done!

[@ColeCoug]

This is one of my favourite channels on youtube I love this so much

[@tomsterbg8130]

I love how you explain the way electrons push on each other. I think that's why Vertasium got into the misconception that electrons don't travel, but they make a field around the wire. It's true that the field is everywhere, but not true that electrons don't push on each other.

[@jankosek5696]

Marvellous. Thanks for creating experimental videos, as there is not much content in Internet in this subject(experimental physics)

[@tomaszbekas]

I came here after watching your current most recent video "An intuitive approach for understanding electricity" and I see that at 23:55 you have a shot from an experiment done in that video. It shows how much time & effort it takes for you to create videos and how much you focus on a quality. I appreciate it very much, kudos to you.

[@anthonybragg5893]

Very good presentation of information easy to understand and answers more questions than expected! Good job!

[@G_Mustafa]

I very much like your videos; topic, explanation, questions and observations keep it up bro

[@hi_tech_reptiles]

Learning about electronic concepts through a phsycisists lens is fascinating. I got into board repair a couple years ago and delved into many of these topics, but hearing it from the bare, fundamental side of physics is another thing entirely. Thanks.

[@bmacdoug]

Awesome video. The second half especially, explains Fourier decomposition in a wonderful, intuitive way. I also liked the reference to 3B1B. Thank-you!

[@gregsmith1719]

Great video! -- Proving that everything is electric, acting as particles, and in groups, discharging to balance the charge faster than we can imagine -- trying to balance itself in a sea of torrential waves. -- Keep it up!

[@SamChaneyProductions]

Amazing stuff as always. For your question at 23:04, I would definitely say it's option number 2. All of our scientific understanding is only models of reality, not reality itself. Each model is built on top of previous models and concepts and each of those concepts only has meaning with respect to the ones which define it. If you take the concept of an atom and remove all other concepts that define it (matter, elements, energy, mass, electrons, nuclei etc.), it becomes meaningless, literally nothing. The only concepts we have which aren't defined entirely by their relation to other concepts are ones that point toward sensory experience directly, like colors, smells, textures, sounds, and even many of those are metaphorical (bright or dull sounding headphones, sharp tasting cheese etc.) This process of building more conceptual models on each-other over time forms the scaffolding for how we conceive of the world and which thus defines what kind of conceptual models we are capable of coming up with going forward. It's a kind of feedback loop that generates more and more "accurate" models of phenomena in the sense that they give us more granularity of what we can reliably predict, but there is no way we'll ever be able to truly describe reality, only ever a gross approximation of it. I like to use the metaphor of a digital camera. Our models of reality are dualistic in that they rely on separating the universe into smaller and smaller bits, like the pixels of a digital camera sensor. No matter how much digital sensor technology improves, no matter how many megapixels we can fit into a single image, it will never be reality. You will always be able to zoom in far enough to see the individual pixels. It would be madness to look closely at a digital photograph and exclaim that reality must be made of pixels, and it's madness to look at our scientific models and exclaim that reality must be made of sine waves. As some say "the map is not the terrain"

[@casimir40ksolomon74]

oh this is soooo cool. This is some S tier science content. Keep up the amazing work man.

[@Sibula]

I recently did a couple courses on signal processing and when you said the slowing down is dependent on the frequency I immediately thought of Fourier transform and how the switching actually has really high frequency components. It was great to see my first intuition was correct.

[@unvergebeneid]

It's a very useful thing to have a mental concept of, for many things. I'm always frustrated when I express something in terms of frequency components and people don't know what I'm talking about because it's a concept that's almost impossible to succinctly express in any other way.

[@sashimanu]

In optics, the “frequency dependent slowing” is called dispersion and is responsible for rainbows, diamond glitter, Dark Side of the Moon album art, and chromatic aberrations, among other things.

[@benjaminmiller3620]

The smearing out of the signal between the switch/first probe, and the destination/second probe is very reminiscent of chromatic aberration. (But in the time domain.)

[@unvergebeneid]

@@benjaminmiller3620 because it's the exact same thing, only in time not space as you correctly said.

[@Sibula]

@@benjaminmiller3620 nice catch!

[@steveokoy]

What you demonstrated is a sort of electrical time domain reflectometer. The "switch" produces a square wave from zero to a voltage V' by flipping the switch on and off fast enough to continuously generate the wave so it can be displayed stably in the oscilloscope trace. A function generator was used for this instead of a mechanical switch. In the square wave voltage that was was applied on the start of the journey comprises of several odd and even harmonics that was displayed below your Time/voltage trace above the scope representing I guess is the spectrum analysis. Very well demonstrated video showing velocity of electrical current in an electrical conductor. Please show your next video passing a wire in steel conduit.

[@ElvenJustice]

Amazing and interesting stuff. I am so glad that people like you exist who love highly complex math to figure that stuff out. Electronics school lost me at "factoring polynomials".

[@ivanbratanov8699]

For us at the college the same phenomena was explained with the extremely small distances between the electrons. So the charges are those to travel at the speed of light, not the electrons. There is something similar to the Newton’s cradle. When you drop the first ball from a certain height it hits the next one while the last is being hit immediately. The space between the balls is identical to the space between the electrons.

[@tchevrier]

not quite. The charges are the electrons. Particles with mass cannot move at the speed of light. It is the EM field that moves at the speed of light.

[@niklas5336]

13:17 you can also see how the "slope" of the wet trace is shallower than the dry trace, which is exactly the result we would *expect* from the speed of light being frequency-dependent! (In theory, we would also expect it to 'ripple' more, but I don't think that's easy to see here)

[@MrZhilvinas]

Actually it seems it had an opposite effect - very heavy damping! The clean air setup showed significant overshoot and ringing, the pipe (dry or wet) had 0 overshoot. This is expected tho, the pipe around the wire basically makes a large parasitic capacitor. This causes high impedance on the line, greatly attenuating higher frequencies. Filling it with water made it a slightly better capacitor, hence more impedance and a slightly slower rise time. The most curious effect imo is how the delay was already near maximum even though just a tiny part of the pipe was filled, and stayed relatively constant thereon. Could simply be that the shots are not truly time aligned though.

[@TT-lf5hi]

I want you to know that I rewatch this video because it does a great job qualitatively explaining the electric field. Thank you.

[@SaltyRad]

im impressed man. I studied EE and i loved your explanation of it. you could be a good teacher.(kind of what your doing now, but you knwo what i mean). its because of these properties that i wanted to try a graphene coated copper wire and see if increases the speed rather than decrease like the water.

[@ArrakisMusicOfficial]

Great video! I have a suggestion for a video I'm very interested in, I've read and heard multiple times that the reason why wires with passing current generate EM field is because of space dilation described by the theory of relativity, since the densitiy of electrons let's say in the middle of the wire is exactly the same, therefore we would expect it to be neutral as it is in rest state. Is that actually true? Would there be an experiment where this could be demonstrated somehow?

[@jackmclane1826]

I remember doing something like that in high school physics... I don't know any specifics any more, but the result stuck. In that setup the potential wave travelled at 2/3 c. But it was definitly dry and not submerged in water. Thicker wire also has a higher inherent capacity. Like you have to draw off more electrons to hold it at +1V potential. If you have a very weak current source, it might also skew the result that way. that could be enough to account for 2 ns.

[@wayneyadams]

The current has no effect on the speed of propagation of the electromagnetic wave. Read my previous comment about why the speed is affected by the medium, and watch the two videos for a better understanding of what is really happening.

[@jackmclane1826]

​@@wayneyadams Maybe I didn't make it clear enough. If you cannot draw out enough electrons fast enough (or your switch has a significant transient), it would also result in a measured delay. Not by a slower potential wave but by the property of the excitation. Not a square wave but a slow decay. The result in the measuring would be the same in practice. As we are talking about nanoseconds here, the current to instantly empty the capacitance of even just wire to -1V becomes significant. Transients of discrete semiconductors can also be in that range.

[@robertdoell4321]

Extremely well explained.

[@timothymuhlfeld5886]

I loved the way you explained the electrons pushing thier field and pushing the other electrons down the wire! And to be sure electrons don't move through wire! Great work!!!!!

[@AlphaPhoenixChannel]

They totally do move through the wire, just slowly

[@wayneyadams]

@@AlphaPhoenixChannel Called drift speed, or drift velocity.

[@beachboardfan9544]

This is a better explanation than any of the other electrical/physicist/scicom youtubers I've seen! 👍

[@jamesmoffat9754]

It would have been a lot simpler if you had 2 lengths of wire. One in free space and the other submerged. use a sine wave generator and compare the phase angle. You could even compare the phase angle at various frequencies. I use this technique on the factory floor to check for proper phase delay.

[@johhnyh9683]

Your excellent presentation and enthusiasm totally engage me. Love your work. Genius is the word that comes to mind.

[@josephshulman4330]

Really enjoyable site I subscribed and definitely looking forward to watching more of your videos !!!!

[@proosee]

When you said that people say that resistance affect speed of electricity I was like "Whaaaat? That's heresy, I would be crucified if I told it in front of my professors", I think for anyone who did a bit of electrical engineering it's kind of obvious that the property those guys were looking for is inductance. Anyway, that was interesting experiment and it was nice to see it on your own eyes.

[@dieSpinnt]

Well, if they transport colloquial BS instead of knowledge with the correct technical terms, but more like religious delusion ("wonder", "fantastic", "never seen" ...), then one should rather leave it alone. Such uninformed half-knowledge does more harm than good:/ Look at you. How easy was it to provide the right information ( trailing phase shift due to inductance, characteristic impedance )? Very easy. Thank you for that!:) But unfortunately something like that has less reach than clickbait...

[@gabrielhacecosas]

I love your videos. I recently read in a physics book that they measured the speed of light in a pipe with moving water and they saw through interference that it went faster in one direction than in another. Will this experiment be the same? Even if the cable is still, if you put water with current in one direction or the other, will the speed of the electricity change?

[@calebdavis719]

Very dope, love that you've worked refractive index into the speed of electricity... mind blown

[@drd1924]

Very nicely done demonstration and experiment...Excellent man !

[@Alan_Hans__]

Nice. The video is nice but the sillyscope is very nice. I'm jealous that my old Tekronix is only monochrome. Older still are the 3 CRO's that I have that are all mono rather than coloured. I wonder if salting the water would make much difference. It changes the refractive index a bit but more importantly it makes the water far more conductive.

[@autumnrain7626]

Sillyscope :P

[@SkyhawkSteve]

I spent a career with Tek, LeCroy, HP, and other scopes, but picked up a 4 channel Rigol for home use for about $500. Boy, it provides a ton of function for such a small price! My old home scope was an analog Tek, and was excellent, but the cheap Rigol really does make life easier.

[@G3rain1]

What about the material of the conductor it self? It would be interesting to see if copper, steel and aluminum wires are different. Or what happens if you place the wire through a material that (almost)complete blocks the EM fields.

[@nsday1]

A lot of this is normally over my head, but you make it easy to follow along. A couple of things that I started to wonder about. 1. Types of conductors. Would Aluminum be different than copper? 2. Shielding. If magnetic fields travel outside of the wire, what about shielded wires? Or am I getting that wrong?

[@mariocesarsousa]

That is really great explanation. It makes clear a lot of details i was trying to understand. 💚💚💚

[@danthompson8991]

I haven't done a bunch of experiments to be able to give you a bunch of data, but there are a couple of things about this that you may want to address as a follow up. Water is an insulator only when it is completely pure, such as deionized water. Water as it comes out of the ground usually contains things that make it slightly to very conductive. You also housed this in a PVC pipe. I have watched many PVC pipes create a static charge simply from wind, to the point they need to have a ground wire connected to them. So, it too has electrical properties that may affect your tests. Of course, it will not change the fact that you were trying to prove, but may offset the data supporting it.

[@sergiureznicencu]

From what I understood in the physics class it is something like this: the system of atoms or molecules is "sensitive" to a couple of specific frequency. You applying a square wave to an atom is like smooshing that signal into the "holes" of frequency that atoms responds to. It's like polarizing light which is filtered by a rotated filter - if it fits the hole than the whole stream passes otherwise it is chopped by a percent (Eugene Khutoryansky video: kzbin.info/www/bejne/borOl3icqZmjY9k). This is also true in our case because the square wave is spread across the entire spectrum so if the system only responds to a couple frequencies the rest is lost energy. The idea here is that the square wave is just that - a square wave. The Fourier analysis makes the point that having an infinite series of sine waves you can reconstruct that signal and this is true. That is however just an analysis and the wave is not such constructed "under the hood" in the real world. What makes it work in the real world is that the building blocks of matter responds to sinusoidal waves. When such a system is hit by a square wave signal it just picks out the energy for the frequencies it is sensitive to from your signal. When you analyze this behaviour you will shockingly find that viewed from the Fourier perspective your square signal is missing some "frequencies" which correspond the the ones the atom is sensitive to. You can also think of this in terms of an antenna and tuner. You can have all kinds of waves hitting that antenna but only the frequencies selected by the tuner will pass. It's also interesting because if you generate a good let's say 1MHz signal you will still be able to "drain" some of the signal energy with a 0.9MHz receiver just a much lower amount than what is broadcasted.

[@potatomancer9473]

Honestly 10/10 video, keep doing what you're doing.

[@Roberto-dd1te]

I understood it better than with two Veritasium videos. Great job!

[@TheTimmy4745]

Does the shape of the loop affect the speed of propagation. EEVBlog posits that the transmission effect is the cause. Corners would propogate faster in the crook. In theory a circle would be slower. Edit: would the water moving affect it at all. Since it is affecting the speed while sitting still would it affect it more while moving. Think a magnet going down a copper tube

[@maxheadrom3088]

A video fit for the current polarized world we live in! 😉 Your videos are awesome, Dr.!

[@stapedium]

I seem to remember that one of the assumptions with Fourier transforms working at steady state was that there was infinite energy in the system. I love how you’ve deconstructed the ideal that electricity propagates at the speed of light. Any chance you can do a series deconstructing the assumptions that we make when using Fourier transforms?

[@jaimeariasfarias6520]

I enjoyed very much your STEM microscope video of a GaAs sample. For a seasone geologist like me, it is amazing to see rows of atoms and actually distinguish smaller and larger radius ions. Thanks for this next experiment. Many thanks and congratulations for the ggod science!! Jaime ARIAS Geologist (1972), Ph. D. in Applied Geochemistry (1978)

[@N0gtail]

Somehow you explained this stuff better in 25 minutes than an entire semester of physics classes.

[@tedmoss]

You took the wrong Physics class. Some people just can't connect theory with reality.

[@wayneyadams]

Then you had a crappy physics teacher. You should have been in my Physics classes.

[@PhiloSage]

In my opinion you might be measuring the voltage at the wrong time. The voltage should be measured somewhere between V*√2 to MAX V. AC is always calculated at the MAX V*√2 as this is the RMS value ≈ actual power. Also you should measure the phase angle between V and I, not just V. It would be interesting to see the change of salt water and fresh water as the dielectric properties are extremely different between the two.

[@davidconner-shover51]

it isn't just dielectric properties, there are also diamagnetic, paramagnetic and ferromagnetic to consider water is diamagnetic, adding salt makes it more so

[@SpaceCadet4Jesus]

In electronics repair school, decades ago, the movement of electrons through a wire was likened to billiard balls in a line, each bumping into the next but moving very little themselves. Seems like that explanation holds.

[@dan_austin__873]

Wow what a gem of a channel. Subscribed 👍

[@RIGeek.]

Electricity travels slower than the speed of light through coax cable. That is what the velocity factor rating is.

[@cowboybob7093]

What's the speed of light through copper? Use X-rays, they'll get through.