Did I even understand this correctly?

I agree with you Clive, being in college for electrical, and Learning about Earth and TT grounding systems, TN Grounding systems, TN-C-S Grounding systems , IT Grounding system's. I don't trust his theory.

Jonathan Hughes

Wow Derek's video has people talking just watched electrobooms take on it now

I didn't watch the original because it's title seemed like a very clickbaity "well aktchually" sorta thing. I remember physics class at university/college and appreciate the deeper physics are there...but haven't thought about them since.

that guy

Thunderfoot did a great video that claims to show electrons with your naked eye. Ok, this is chemistry, but looks cool. https://youtu.be/rKTe1wom4q8

Simon York

"The difference between theory and practice is that, in theory, there isn't one, while in practice, there is." :)

Charles

I think you might be misremembering the field thing. It sounds almost like the skin effect, where for high-frequency AC current, the outermost layer of the conductor ends up carrying most of the current, with very little in the middle of the core. The depth to which the bulk of the current actually uses goes down with increasing frequency. So it is really inefficient in terms of how much metal you end up using to handle a given nominal current. Using finely-stranded wire helps, as the ratio of "skin" to "body" of each conductor is much higher for any given frequency. Note this only applies with higher frequencies. At line frequency (50/60Hz) or even into audio frequencies (tens of kilohertz), skin effect is negligible, despite what your local audiophool might tell you :) Overhead lines are indeed generally made of aluminum, with a steel core(s) for structural support. Aluminum is used because it is a better conductor, by weight, than copper. Copper's a better conductor per unit area, but if you have a mile-long aluminum cable weighing the same as a mile-long copper one, the aluminum one will have almost 3.5 times the cross-sectional area, which more than makes up for copper's higher conductivity.

Charles

I wish Derek hadn't done two parallel cables, because it's leading everybody to think in terms of capacitance or worse, antenna transmission of energy. A more instructive approach would be a circle with a circumference of one light-second, with the bulb directly across from the switch. According to the theory, the bulb should light at 1/π seconds, not a half second or whole second as you'd expect, despite there being no significant coupling between opposite sides of the circuit. (The comment loss is probably due to Amazon having major issues today. I'm seeing it, too.)

George Dorn

If energy didn’t flow through air, we wouldn’t have radio waves for cell phones or wi-fi to communicate with. Although we’re dealing with very different wavelengths and power levels, the fundamentals of Maxwell’s equations still work just the same.

At the sub atomic level it is hard to prove a theory. You have to go with what has least problems. The current (do you see what I did there) theory works in the real world, and while difficult to prove seems a better bet than this one, which cherry picks parameters to suit the argument.

AlfaGuy

The fancy theory cannot be correct in that current / power / energy in fresh air outside of the condutor otherwise it would be impossible to blow a fuse. Equaly conventional theory cannot be correct otherwise ac current beyond a certain distance due to the speed of light would be unable to deliver any power due to the electrons having to return rather than making the whole trip :( It was over 40 years ago that I did right and left hand rule, and hole current, left hand rule works, right hand rule stuff is witchcraft :(

Not having seen the original video (only this one from Big Clive) my main observation would be that I’d always heard that around 1MHz and higher was where the “skin effect” started to matter and increasingly the energy flow just skimmed around the wires/copper traces (and above about 1GHz that skin effect needs to be designed for explicitly as you’re basically dealing with radio waves that are merely encouraged to stay near your circuit). At much lower frequencies AFAIK the conventional electrical flow in wires is the dominant effect. So it seems the original video may have mixed up high frequency theory and lower frequency theory, or how important the two are at different frequencies. Ewen

Ewen McNeill

If electricity flows outside of the wire then why do I need to remove the insulation before I get a shock?

Basically superconductivity at ambient temperature.

Frank

I'm not saying that he is wrong, but I can't see how electricity flows in the field around the wires, and not the wires themselfs. Wouldn't that mean that an insulator or conductor's definition needs to be changed as well? Also Electroboom doesn't agree with it either, and he is def smarter than I am about this subject.

I would think the electrical/magnetic field hypothesis would be easily tested by wrapping the load or the source in a mumetal shield. Well, "easily" in comparison to testing some physical hypotheses... You might not be able to prove it this way, but you could almost certainly disprove it.

Charles

The way I think of it is that electrons are negatively charged so they are repelled by a negative voltage!

the model Veritasium put up is idealized for sure. Many additional factors will perturb the observed behavior, and the experiment with wires stretched the distance to the moon and back would be influenced by resistance, inductance and capacitance. Plus the electromagnetic field gradient from the earth and sun, and all the noise therein. The electromagnetic field around the wires would need to have all these factors excluded to imagine the outcome in an ideal universe. Problem is, most practicing electrical workers work in the everyday world, and just like Newtonian physics sufficing and not needing relativity to model the forces in a bridge, conventional electrical circuit models work just fine. Good job getting the grey cells churning Clive, entertaining and informative as usual!

Geoffrey Waldo

The potential for potential;)

Geoffrey Waldo

DC doesn't exist. Unless you have an eternity to measure it.

Mike Page

I remember that high voltage transmission line uses the field around the wires more for current flow than the conductors themselves and that is one reason they can use aluminum to reduce weight. (no reference). Scary and beautiful experience was going to look at LA night sky but being under several high voltage transmission feeds coming over the bluff down into the LosAngeles basin.. The air was loud with buzzing and even crackling and I could feel the hair on my arms stand up. I kept hunching over / ducking because so intense - but being drawn close to the edge (where the lines sagged closest) because of the view.

Your pic of electrons in a cable looked too much like people in a tube train at rush hour. The best way to get them to move along would be a cattle prod. That's my theory anyway.

Ymir the Frost Giant

The first transatlantic cable was a single core hence many of the issues they had. There is a good IEEE Spectrum article - Google "the-first-transatlantic-telegraph-cable-was-a-bold-beautiful-failure" If you search for pictures there are a few of the first (one in a BBC article) and some images of later cables - ones that worked though!

Mr B Shepherd

Thank you so much for making this video. I also commented on his video calling him out for it being rubbish. I have also watched videos about the transatlantic cable and know that he has missed so much. I also thought of you and your tiny circuits. If power was really translated though the air rather than the wire then tiny circuits would never work because they would be completely swamped out by the much larger electrical field. Also resistors would be meaningless since the entire current would be flowing around them rather than through them. Big Clive is still my favorite Youtuber!

Matt Larson

The stuff Veritasium is talking about is completely correct, but just not relevant to the topic. Dave from EEVBlog has a really in depth video about this and even some practical examples in the end: https://www.youtube.com/watch?v=VQsoG45Y_00

Paul Paulson

This is a big mind bender and remember lecture in electron theory. For normal low frequency electrical and electronic design these theory is not needed but only need to get 1Mhz above with odd effects happen. I remember that even with distribution network under sea cables are hv DC not AC because of skin effect.

N. Shaun Tremayne

To test this theory, surely you would have to light the lamp without the wires. Also for DC wouldn't the magnetic fields be static and there incapable of transferring energy? Otherwise wouldn't transformers work for non pulsed DC?

Dr Andy Hill

Wow.. you perfectly expressed my feeling about that video. I can't write it better myself. He's a youtuber and needs that lots of people watch his video and talks about it that's IMHO primary goal of that video. You need something that triggers that storm.

Badger

I remember when I was a physics undergraduate in 1977, we shared our first year lectures on electromagnetism with the electronic engineering students. When we came to covering the 'Poynting vector' (S=E x H), that is to say, the instantaneous power flow in a conductor, the electronics students were outraged. All the same arguments were put forward by them, including the idea that it doesn't apply at DC or low frequencies, or in screened cables. The pivotal part of the problem for engineers is the mental model of the flow of electrical current being synonymous with the 'flow' of electrons. From a practical standpoint it's entirely useful, but it's misleading and incomplete when you dive deeper into the physics of what is actually happening. Yes, the power flow in a wire is perpendicular to the surface. Both Poynting and Heaviside came independently to the same conclusion, and it's entirely consistent with physical laws like the conservation of energy and the conservation of angular momentum. That doesn't stop it from being counter-intuitive, and that's what really irks engineers.

Dave Davies

It's almost like Veritasium went out of his way to generate a lot of youtube traffic, almost.

Tokkan FX

More like Miguel Microwattson ;) I'll let myself out.

MrTridac

Every time Miguel Wattson the electric eel releases a jolt of electricity, a festively-decorated Christmas tree next to his tank at the Tennessee Aquarium flickers and glows.

Andrew Donaldson

I watched David Jones' video and thought it was great. I will watch yours soon. :)

Ryan Coleman

Electrons are actually the souls of nuns going to and from tiny strip clubs. It's a theory, but not a widely accepted one.

Mark Trombley

Only real problem with Derek's video is that he presented the deeply theoretical data as if it were real-world practical data. Theory is awesome. But practice rarely matches it perfectly.

Scott Miller

I think Veritasium presented it in a way to generate controversy. None of these statements should be controversial: When you close the switch, the battery starts pushing current down the wire. A current in a wire produces a magnetic field. A changing magnetic field induces a current in the neighboring wire. (These are how generators and motors work). And that current will flow through the bulb. It may be very, very tiny, but it will flow. And the field propagates at the speed of light, so that current will start flowing after the speed of light time between the battery and light. But the circuit he presented would in reality have a huge capacitance. It would take a very, very long time for the circuit to reach the steady state of full current. And the difference between "tiny current through the bulb" and "full current through the bulb" is why it's controversial. People are arguing past each other because they are two different states.

SaberTail

That's got me thinking about how lightening travels (upwards).

Andrew Donaldson

I'd posted a comment directly addressing this video which seems to have vanished in the process of editing. Not sure what I ran afoul of, but hope it doesn't happen again. While I have a few beefs with Derek's video, the underlying concepts are correct, even for cables with shields, and even down to DC. Consider a coaxial cable. Any current along the centre conductor is an annular magnetic field around the conductor. A balanced opposing current in the shield will cancel that field outside the shield, but add to it in the dielectric in between conductors. Meanwhile, if there's any voltage between conductors, there's a radial electric field. The poynting vector given by this magnetic and electric field points along the length of the cable: power is transmitted entirely in the dielectric between conductor and shield. Power will want to flow every which way, but the presence of conductors will certainly influence it. How much of it gets transferred by the line of sight path, and whether that's enough to consider the lightbulb lit is arguable, but if you're willing to accept an arbitrarily small current lighting the bulb, then Derek's 1m/c claim is okay.

When you really dig down to it, individual electrons transferring energy do so by exchanging photons! The two explanations are not mutually exclusive of each other. When you move one electron, how do other electrons know that anything happened? The motion of one electron sends out photons which hit other electrons transferring momentum.. There are limits to how far you can carry this intuition as the idea of a photon as a particle is a classical concept while photon exchange is a quantum mechanical process. But at the level where Mawxell's equations work, the underlying quantum mechanics describes it perfectly.

i suspect there is an element of truth involved - similar to how sound travels via pressure waves in the air - likely the idea that electrical power travels via electron flux of interconnected electron fields (not the same as EM radio waves - otherwise wireless power wouldn't be so inefficient) such that it isn't individual electrons that are transferring the energy, but similar to photons, another concept is moving along the wire and actually delivering the energy

Russell Peake

I watched Derek’s video. Twice. I’m neither an electrical engineer or electrician. Just an interested enthusiast. My question is. If the power / energy is being transmitted along the wire through magnetic fields. Why don’t the fields interfere with one another? Imagine the hundreds of separate fields in a large control panel.

Well, remember their caveat that their theoretical magical cable has zero resistance or impedance.