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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]

#111

Post by Jansen312 »

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…

As a parent, Veritasium would be way more preferred teacher to inspire students to search for answer. There are many stellar students who scored A* that later in life just dump what they learnt. You'll be surprised how many medical students didn't make it to MD or not a MD anymore a decade later. Having someone that spurs you to work for it is a weight in gold itself than a great tutor helping you score full understanding and get that A*.

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

#112

Post by y04nn »

The first signal is a close RF transmission, billions of people rely on it everyday, a current disturbs the electromagnetic field and and an antenna, sometimes thousands of kilometers away, detects a very small variation in the field (-120dbm @ 50Ω = 0.2μV). This is how our cellphones, wifi, GPS, RFID works. So, even if you disconnect the bulb and the switch you can create a current in the bulb by turning on and off the switch.

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

#113

Post by notfed »

negative_zero wrote: post #101
tpush wrote: post #76

So, I genuinely do not get the "controversy" over the Veritasium video. AFAIU, the entire point of the video was to show that electricity travels not through wires but via electric fields ("through the air" so to speak). To illustrate this, he sets up an experiment with parameters such that the conclusion can only mean that some electricity has traveled to the bulb before any could arrive through/around the wires. He…

I think the controversy is because that while being technically correct (bar a couple of mistakes) there are two main issues: 1) To get the result presented heavily depends on the experimental setup and this appears to be hand-waved away (or for the cynics: deliberately obscured) as it would detract from the impact of the video. 2) The definition of "ON" in the video is not what anybody would reasonably define as "ON…

I still don't buy "then yes this is correct". If "ON" is defined as a state where ANY electromagnetic field flows into the lightbulb, then it is "ON" even before you throw the switch, because other photons are already shooting around all over the place, including from the neurons in your body pondering the result just before you throw the switch.

The definition of "ON" is exactly the main controversy with this and not a subtle detail.

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

#114

Post by BenFrantzDale »

negative_zero wrote: post #101
tpush wrote: post #76

So, I genuinely do not get the "controversy" over the Veritasium video. AFAIU, the entire point of the video was to show that electricity travels not through wires but via electric fields ("through the air" so to speak). To illustrate this, he sets up an experiment with parameters such that the conclusion can only mean that some electricity has traveled to the bulb before any could arrive through/around the wires. He…

I think the controversy is because that while being technically correct (bar a couple of mistakes) there are two main issues: 1) To get the result presented heavily depends on the experimental setup and this appears to be hand-waved away (or for the cynics: deliberately obscured) as it would detract from the impact of the video. 2) The definition of "ON" in the video is not what anybody would reasonably define as "ON…

His technical errors include the “correct” multiple-choice answer being that the time to turn on is “1/c s”. That evaluates to 3.3e-9 s^2/m. It’s not even a time. Failing basic dimensional analysis is grossly sloppy.

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

#115

Post by spookthesunset »

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 actually think he intentionally worked with (some of) these other youtubers. I've been enjoying watching all the "regulars" I follow on youtube challenge his assertions.

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

#116

Post by tshaddox »

haberman wrote: post #93
tpush wrote: post #76

So, I genuinely do not get the "controversy" over the Veritasium video. AFAIU, the entire point of the video was to show that electricity travels not through wires but via electric fields ("through the air" so to speak). To illustrate this, he sets up an experiment with parameters such that the conclusion can only mean that some electricity has traveled to the bulb before any could arrive through/around the wires. He…

If electricity doesn't travel through wires, why do resistors dissipate heat? I'm having trouble understanding what is even being claimed. Electrons are moving, without the movement of the electrons there is no electricity travel, without the wires there is no flow of electrons, so what does it mean to say that electricity doesn't travel through wires? Is the claim just that the electricity, by way of fields, travels…

> so what does it mean to say that electricity doesn't travel through wires?

I think it’s specifically that the energy flux has a well-defined vector at every point in an electromagnetic field, and those vectors do not point along the wires.

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

#117

Post by spookthesunset »

userbinator wrote: post #109
motoxpro wrote: post #77

Earlier quoted context omitted.

I think the point is to get people excited about science and show what is possible/spark curiosity rather than trying to recreate a classroom. You can see this by all the kids that take his classes. There is space for both to exist.

I wonder how many of those kids are going to reconsider once they find out that doing "real science" is, in reality, far more boring.

Same could be said about almost all of the "technology" field most of us work in. I mean think of how many people dream of being a game developer... what a shock that must be.

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

#118

Post by foxfluff »

jeffbee wrote: post #106
foxfluff wrote: post #90

Earlier quoted context omitted.

"I have never in my life length matched the two lines of a differential pair, including at 10 GHz. Never." - Rick Hartley https://youtu.be/QG0Apol-oj0?t=2765

I mean ... he's saying right there on the slide there's less than 1mm of length error budget at 10GHz.

And that's gobs. What's your typical space between the lines in a pair? Five mils? You run them side by side and you'd be hard pressed to make a length error significant enough to matter. Yeah you do need to be aware of it enough to ask whether you're good when you're routing a really weird loop.. but for the vast majority of things and sane routing, you can just eyeball it or don't need to care at all.

Point is, a lot of people seem to think length matching is critical ("for anybody that is working on anything over couple hundred megahertz") and application notes would have you believe as much but the industry experts and theory I've found suggest it's way overstated.

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

#119

Post by spookthesunset »

soheil wrote: post #79

This Veritasium video was the first instance of clickbate 2.0 We're going to see more and more this type of video. Instead of the thumbnail and title of the video being extremely controversial to attract views, the thesis of the video will be controversial to create endless online debate.

Trolling 2.0?

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

#120

Post by tigerlily »

afiori wrote: post #89
tpush wrote: post #76

So, I genuinely do not get the "controversy" over the Veritasium video. AFAIU, the entire point of the video was to show that electricity travels not through wires but via electric fields ("through the air" so to speak). To illustrate this, he sets up an experiment with parameters such that the conclusion can only mean that some electricity has traveled to the bulb before any could arrive through/around the wires. He…

In my opinion the video made a couple of mistakes, which I think ElectroBoom's response* addresses nicely. Also its proof using the pointing vector to show the flow of energy is misleading; In the video Derek shows that the energy flows toward the lamp when the circuit is already in a stable configuration, but the point of the video is to explore what happens before the circuit reaches that configuration. This is rel…

I thought it was the Poynting vector? Easy to remember because it points in the direction of power flow :)
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