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I bought 1000 meters of wire to settle a physics debate [video]

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Re: I bought 1000 meters of wire to settle a physics debate [video]

#61

Post by QuantumG »

jacobolus wrote: post #23
0xTJ wrote: post #5

That Veritasium video is one of the most controversial educational videos I've seen. I think one of the issues with it is that it's a bit pedantic, but also ignores other issues, that invites other people to be pedantic about it.

Controversial is fine to the extent the controversy shows people struggling toward clearer understanding and better explanations, and as long as all parties are operating in good faith (i.e. not being deliberately misleading). Let me highly recommend Mehdi Sadaghdar’s (ElectroBOOM) excellent response video https://www.youtube.com/watch?v=iph500cPK28 which does a great job of empirically investigating and theoreticall…

Teaching. What a concept.

It warms my heart to see a generation of scientists, engineers and communicators attacking frontiers again.

For a while there it felt like just a few of my friends were fighting for the future and everyone else had written it off to Sci-Fi.

Re: I bought 1000 meters of wire to settle a physics debate [video]

#62

Post by stormbrew »

paxys wrote: post #11
0xTJ wrote: post #5

That Veritasium video is one of the most controversial educational videos I've seen. I think one of the issues with it is that it's a bit pedantic, but also ignores other issues, that invites other people to be pedantic about it.

That video perfectly summarizes online discourse. I personally found it fantastic as a resource. It was the best and most clear explanation of transmission of energy in an electrical circuit that I have seen. It debunked a lot of myths in my head that we were all taught in school. The thought experiment he proposed was just a hook to keep people interested - and it certainly did the job. Because it is a popular inter…

I'm sorry but no, the original video does clarify some important things that people misunderstand about transmission of electricity, but then it piles on a bunch of other really unclear information with no explanation. It answers a question with about 8 other questions and then offers no help in understanding any of them.

You can't just say "there's electricity at the light bulb nearly immediately! (oh by the way it's not very much electricity but I'm not going to explain why or even how much less, and it's probably not even enough to turn on an LED but I'm not even going to mention that)" and then get pissy when people are like "???!??!?!" It's pretty blatantly deliberately misleading and confusing in order to stir up exactly this controversy.

Especially since the effects he's describing are probably (as mentioned in this video) because of capacitance, and are completely dependent on the 1m distance between the wires across the entire span, a constraint he mentions basically once and then never again, and never says explicitly that it's related to the effect.

This video and electroboom's videos are far more educational, and more importantly don't leave you hanging with a bunch of new questions with no resources provided to answer them.

Re: I bought 1000 meters of wire to settle a physics debate [video]

#63

Post by UncleOxidant »

Laremere wrote: post #25
0xTJ wrote: post #5

That Veritasium video is one of the most controversial educational videos I've seen. I think one of the issues with it is that it's a bit pedantic, but also ignores other issues, that invites other people to be pedantic about it.

As much as I love Veritasium, I feel the OP video is better than his. Actually doing the experiment is really good, and it honestly feels like he was fishing for another debate like the faster than wind car by giving only a super theoretical and unintuitive explanation. (I don't have any real evidence of that, but it does /feel/ like it.) I also wonder what would happen if, instead of a setup like this: ┏───────light…

I think the issue with the square would be that the capacitance would be much, much smaller since the wires are separated by a large distance (square law). The capacitance of the original setup is already quite small, but at least it's noticeable on a decent scope. But I doubt you'd see that effect in the square setup.

The other issue with the Veritasium "setup" was that he specified that the wires had no resistance. That being the case the RC time constant would be 0 and thus you wouldn't see that initial charging of the capacitance (and associated current flow) because it would happen instantaneously under those assumptions.

Re: I bought 1000 meters of wire to settle a physics debate [video]

#64

Post by charcircuit »

Laremere wrote: post #25
0xTJ wrote: post #5

That Veritasium video is one of the most controversial educational videos I've seen. I think one of the issues with it is that it's a bit pedantic, but also ignores other issues, that invites other people to be pedantic about it.

As much as I love Veritasium, I feel the OP video is better than his. Actually doing the experiment is really good, and it honestly feels like he was fishing for another debate like the faster than wind car by giving only a super theoretical and unintuitive explanation. (I don't have any real evidence of that, but it does /feel/ like it.) I also wonder what would happen if, instead of a setup like this: ┏───────light…

The current will always start following after the distance between the switch and bulb divided by the speed of light amount of seconds.

Re: I bought 1000 meters of wire to settle a physics debate [video]

#65

Post by ghotli »

Laremere wrote: post #25
0xTJ wrote: post #5

That Veritasium video is one of the most controversial educational videos I've seen. I think one of the issues with it is that it's a bit pedantic, but also ignores other issues, that invites other people to be pedantic about it.

As much as I love Veritasium, I feel the OP video is better than his. Actually doing the experiment is really good, and it honestly feels like he was fishing for another debate like the faster than wind car by giving only a super theoretical and unintuitive explanation. (I don't have any real evidence of that, but it does /feel/ like it.) I also wonder what would happen if, instead of a setup like this: ┏───────light…

Hey, did you make that ascii art by hand or did you use a tool I don't know about? If it's a tool I'd like to use it :)

Re: I bought 1000 meters of wire to settle a physics debate [video]

#66

Post by JonathonW »

Laremere wrote: post #25
0xTJ wrote: post #5

That Veritasium video is one of the most controversial educational videos I've seen. I think one of the issues with it is that it's a bit pedantic, but also ignores other issues, that invites other people to be pedantic about it.

As much as I love Veritasium, I feel the OP video is better than his. Actually doing the experiment is really good, and it honestly feels like he was fishing for another debate like the faster than wind car by giving only a super theoretical and unintuitive explanation. (I don't have any real evidence of that, but it does /feel/ like it.) I also wonder what would happen if, instead of a setup like this: ┏───────light…

The further the battery and switch get away from the light, the less current you'll see at the battery at (sqrt(2)*width)/c s, since the electric and magnetic fields around the battery and wire will drop in strength as you move further away from them.

Put another way, the main reason this effect is observable in the way shown in the video is because the light and battery, and the wires between them, are so close together. Move them further away, and, per the inverse square law, you'll start seeing a much lower induced current-- the effect may still be there, but it won't be measurable over the noise floor of the experiment setup.

Re: I bought 1000 meters of wire to settle a physics debate [video]

#67

Post by charcircuit »

lmilcin wrote: post #9

Fun to introduce general population to some interesting physics but please, don't call it "settling physics debate". There is NO debate. Not physics debate, not even practical debate because that knowledge is in practical everyday use. We know signals in wires take time to propagate and I have to take this into account when I design my circuits. Things like matching lengths of traces (especially differential pairs) s…

>There is NO debate

I'm guessing you never checked the comment section.

Re: I bought 1000 meters of wire to settle a physics debate [video]

#68

Post by [deleted] »

nathan_f77 wrote: post #20

I don't think it's possible to detect a 200uA current across the resistor immediately after the switch is turned on. If I understand it correctly, then this would mean that information is being sent faster than the speed of light. Surely this small instant current must be caused by some kind of capacitance or interference.

[deleted]

Re: I bought 1000 meters of wire to settle a physics debate [video]

#69

Post by fouc »

pclmulqdq wrote: post #54
JshWright wrote: post #43

Earlier quoted context omitted.

> I think one of the issues with it is that it's a bit pedantic, but also ignores other issues, that invites other people to be pedantic about it. I think the video is intentionally misleading. He got a taste of how "successful" a controversial video can be with the "Wind powered car going faster than the wind" thing, and he's leaning into that. I just don't see any other explanation for how he chose to frame the pro…

I completely agree. When I got an EE degree, most of the content was about how electric fields work. It's not a simple concept. That video was reductive to the point that it made me angry. For all practical purposes, he is wrong, and he should admit that.

Not everyone has an EE degree.. As far as I can tell, the majority of the video seemed like a honest way of explaining the electric field / "flow of electricity" phenomenon to the layperson.

Re: I bought 1000 meters of wire to settle a physics debate [video]

#70

Post by tgsovlerkhgsel »

amelius wrote: post #45

This is basic transmission line theory. https://en.wikipedia.org/wiki/Transmission_line

It may be basic, but just the _existence_ of this field wasn't something that was on my radar, let alone all the details and implications. This was certainly the most interesting and enlightening set of videos I've seen this year.

I particularly like this one because "I want to get an oscilloscope and see what is actually going on" was my first thought, and this video saves me the effort of trying to set up what would be a much more limited version of the experiment. The promised followups also cover exactly what I'd like to see tried next.

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