Veritasium - How Electricity Actually Works. It's mind blowing.

[mxnerd]

Learnt electronics before, but never thought electricity is so complex and mind blowing.

==

1st video. The Big Misconception About Electricity

2nd video. How Electricity Actually Works

 

[RLGL]

eeh, some truth but the topic still has not been explained by scientists. He is not a scientist.

 

[VashHT]

Hmm watched the first video and it's kind of interesting. Seems to be saying the electron flow is more of a by product rather than it being the thing generating the fields. Very basic explanation for it but an interesting thought.

 

[Captante]

Cool but not nearly as cool as implied by thread-title.

 

[Red Squirrel]

There's been lot of debate in the science youtuber community on it and it does make you think differently about how electricity works.

This guy actually setup an experiment to test the theory:

Personally I think it's mostly capacitive/inductive coupling that is causing the phenomenon. The two wires close together for a long distance is basically a big capacitor. Probably get very interesting results if you start to use high voltage like a couple kv.

Be interesting to see this experiment done over a high voltage corridor that's been powered off. I don't imagine it would be easy to convince the hydro company you want to experiment on a 500kv line though.

 

[Captante]

Really any measurement of the "speed" of electricity is actually measuring the "conductivity/resistance" of the medium it's traveling through.

A lightning bolt would be the best example of "pure" electricity I can think of and (unless it's generated in hard-vacuum) even it would have to contend with passing through atmospheric gasses.

Lightning-bolt speed has been measured at approx 270,000 mph.


However:

"In the case of an electrical cord connecting a table lamp or some other household item to a power source, the copper wire inside the cord acts as the conductor. This energy travels as electromagnetic waves at about the speed of light, which is 670,616,629 miles per hour,1 or 300 million meters per second."

~ Vivantsolar.com

 

[Scarpozzi]

Really any measurement of the "speed" of electricity is actually measuring the "conductivity/resistance" of the medium it's traveling through.

A lightning bolt would be the best example of "pure" electricity I can think of and (unless it's generated in hard-vacuum) even it would have to contend with passing through atmospheric gasses.

Lightning-bolt speed has been measured at approx 270,000 mph.


However:

"In the case of an electrical cord connecting a table lamp or some other household item to a power source, the copper wire inside the cord acts as the conductor. This energy travels as electromagnetic waves at about the speed of light, which is 670,616,629 miles per hour,1 or 300 million meters per second."

~ Vivantsolar.com

The first scientist video said don't factor in resistance!

 

[Captante]

The first scientist video said don't factor in resistance!

Wouldn't you HAVE to consider any resistance/conductivity for accuracy?

Not implying I have any idea not being a scientist myself but it makes sense. For example I've read that burying power-lines can significantly slow and weaken power transmission vs high-tension lines on towers.

 

[Ken g6]

Personally I think it's mostly capacitive/inductive coupling that is causing the phenomenon. The two wires close together for a long distance is basically a big capacitor.

That is correct, and that's basically what the OP's second video explains. I think the key thing to understand is that, initially, the wires behave the same whether they form a circuit or not.

 

[mxnerd]

That is correct, and that's basically what the OP's second video explains. I think the key thing to understand is that, initially, the wires behave the same whether they form a circuit or not.

Guess that's why high voltage line is so dangerous? You have to keep a safety distance from it or you will be zapped like a fly if there is water/rain/moisture?.

 

[[DHT]Osiris]

Guess that's why high voltage line is so dangerous? You have to keep a safety distance from it or you will be zapped like a fly if there is water/rain/moisture?.

Pretty sure that's just a path of least resistance to ground. Wires are insulated, but wire insulation + water + human body (water) < wire.

 

[deadlyapp]

Pretty sure that's just a path of least resistance to ground. Wires are insulated, but wire insulation + water + human body (water) < wire.

Most HV lines are not insulated, unless you count the insulators that are at the trees. With that said, it's usually path to ground or path to complete the circuit.

 

[Ajay]

eeh, some truth but the topic still has not been explained by scientists. He is not a scientist.

PH.D in Physics education and research. I’m sure he’s a total idiot

 

[Captante]

PH.D in Physics education and research. I’m sure he’s a total idiot

Those degree's COULD be from Trump University!

 

[Red Squirrel]

Guess that's why high voltage line is so dangerous? You have to keep a safety distance from it or you will be zapped like a fly if there is water/rain/moisture?.

Yep it can arc if you get close enough. Though probably need to get pretty close for that, but I rather not chance getting within arms length that's for sure lol. While electricity takes the path of least resistance it does not mean it takes ONLY that path. You get close enough to a line and it could potentially arc at you.

As as side note it's very interesting hanging out under a 500kv line as you can actually feel the electricity, and hear it. It almost feels like static discharge, and even kind of sounds like it. Kinda makes me wonder how many losses there are over a long distance. I imagine there is probably a whole lot of engineering that goes into defining the voltage of a transmission line as there are trade offs in the kind of losses you get. Low voltage means more resistive losses in the actual cables but high voltage means more emission losses, if that's the right term to use.

Took this pic a while back, these lines have always seemed kinda low. Arm hair was tingling while under there. The pic exaggerates the sag.

https://imgur.com/6VxxQ3K

500kv coming from 2 big hydro dams, heading down south. I think it feeds my city too. It's actually one of few 500kv corridors in Ontario.

I want to go back to that spot one night with a fluorescent tube to see if it lights up. I think it would. Could make for some interesting photography.

 

[PowerEngineer]

The description of how power lines work in the first video is actually correct. The power being carried by the power lines is actually in the electromagnetic fields around them, and so much of what determines what power flows on a line is determined by what surrounds the actual conductors. You can think of the power lines as wave guides for directing electromagnetic energy.

While the resistance in a power line is completely determined by the characteristics of the conductors, the power line inductance is determined by the distances between the (three phase) conductors and between the conductors and the ground (which is essentially a conducting plane). There is some capacitance created between the conductors, however most of the capacitance is between the conductors and the ground (and is shunt rather than in series with the resistance and inductance).

Nonetheless the misleading visualization of how power lines work is easier to grasp and provides a basis for simpler (than wave equations) calculations that give correct answers. Perhaps not unlike the emergent gas equations being useful even though they gloss over the actual interactions of individual gas molecules.

 

[IronWing]

I think that quick mention of microcircuit design toward the end of the second video is a point to ponder. Will the limiting factor in node shrinks be thermal, field interference, or quantum entanglement?

 

[Red Squirrel]

That got me thinking, if you were to add a power line inside a metal tube would that start to impede on the current as it's creating eddy currents in the magnetic field? Then again, BX and EMT is a thing, and I never heard of it causing an issue. But because both sides of the circuit are inside the same pipe maybe that's why? The fields basically cancel out?

 

[uclaLabrat]

The description of how power lines work in the first video is actually correct. The power being carried by the power lines is actually in the electromagnetic fields around them, and so much of what determines what power flows on a line is determined by what surrounds the actual conductors. You can think of the power lines as wave guides for directing electromagnetic energy.

While the resistance in a power line is completely determined by the characteristics of the conductors, the power line inductance is determined by the distances between the (three phase) conductors and between the conductors and the ground (which is essentially a conducting plane). There is some capacitance created between the conductors, however most of the capacitance is between the conductors and the ground (and is shunt rather than in series with the resistance and inductance).

Nonetheless the misleading visualization of how power lines work is easier to grasp and provides a basis for simpler (than wave equations) calculations that give correct answers. Perhaps not unlike the emergent gas equations being useful even though they gloss over the actual interactions of individual gas molecules.

PV=nRT is good enough for anyone not trying to build a thermonuclear device damnit.

Ill die on this hill 😂

 

[FelixDeCat]

eeh, some truth but the topic still has not been explained by scientists. He is not a scientist.

But he plays one on Youtube. He has does have beady eyes however, and therefore should not be trusted.

 

[igor_kavinski]

Arm hair was tingling while under there. The pic exaggerates the sag.

I want to go back to that spot one night with a fluorescent tube to see if it lights up. I think it would. Could make for some interesting photography.

I wouldn't go there in a million years. You are either extremely reckless or you have meddled with electricity enough to understand it completely.

 

[igor_kavinski]

But he plays one on Youtube. He has does have beady eyes however, and therefore should not be trusted.

He actually beat a physicist.

A YouTuber bet a physicist $10,000 that a wind-powered vehicle could travel twice as fast as the wind itself — and won

A UCLA physics professor bet a popular science YouTuber $10,000 that one of his videos promoted fallacious physics. The YouTuber won.

www.businessinsider.com

Though not sure if he was the sole brainstormer or if he had his whole team ponder on that problem.

 

[[DHT]Osiris]

He actually beat a physicist.

A YouTuber bet a physicist $10,000 that a wind-powered vehicle could travel twice as fast as the wind itself — and won

A UCLA physics professor bet a popular science YouTuber $10,000 that one of his videos promoted fallacious physics. The YouTuber won.

www.businessinsider.com

Though not sure if he was the sole brainstormer or if he had his whole team ponder on that problem.

I remember that guy. IIRC he exploited a fairly well known and well-trodden road in sailing (sailboats can travel faster than the wind as well).

PV=nRT is good enough for anyone not trying to build a thermonuclear device damnit.

Ill die on this hill 😂

There's an XKCD post (might have been a what-if) that I can't seem to find at this time that expressed a similar thought, that at a certain point temperatures just don't matter anymore. Like after 10M degrees or something, the effects on virtually everything are identical so it doesn't really mean anything beyond academic curiosity.

 

[Ajay]

That got me thinking, if you were to add a power line inside a metal tube would that start to impede on the current as it's creating eddy currents in the magnetic field? Then again, BX and EMT is a thing, and I never heard of it causing an issue. But because both sides of the circuit are inside the same pipe maybe that's why? The fields basically cancel out?

The magnetic fields aren’t strong enough to figure in, IIRC. It not like designing superconducting magnets for the LHC.

Also, what you are describing is basically a COAX cable. These, as you probably know, help reject external interference and maintain very stable fields in the signal conductor with low leakage. Same thing with fiber optic cables. It’s a small, small world with nice continuous cross sections (the HamiltonIan equations are generally solvable resulting in numerically calculable infinite series).

Geez, 35 years on and looking at math behind these E&M problems just gave me a headache

 

[uclaLabrat]

I remember that guy. IIRC he exploited a fairly well known and well-trodden road in sailing (sailboats can travel faster than the wind as well).


There's an XKCD post (might have been a what-if) that I can't seem to find at this time that expressed a similar thought, that at a certain point temperatures just don't matter anymore. Like after 10M degrees or something, the effects on virtually everything are identical so it doesn't really mean anything beyond academic curiosity.

I would imagine that gasses stop behaving anywhere close to ideality as they approach plasma (north of 10K deg or so) and thus that relationship breaks down substantially around that range. Hard to have things like inelastic collisions and intermolecular interactions once your electrions go all anarchist 😂