I bought 1000 meters of wire to settle a physics debate [video] • Hacker News Board

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

#191

Post by dehrmann » Sat, Dec 18, 2021, 8:00 AM UTC

y04nn wrote: post #112

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…

Ignoring how accurate calling it RF is, so the experiment showed that electrons travel faster through air than through copper, you can see that, and the two delays are what you'd expect them to be?

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

#192

Post by bagels » Sat, Dec 18, 2021, 8:06 AM UTC

causi wrote: post #187

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…

He sets up the parameters so that the bulb would turn on by that little electricity That's the bit where he's factually wrong. He's made this illogical world where the tiny amounts of electricity in field lines well outside the wire trigger the lamp but the leakage current and other sources of current don't. If you're going to be pedantic about something you have to be pedantic about the whole thing, damn it. Veritas…

Also an absurdly long superconductor.

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

#193

Post by wodenokoto » Sat, Dec 18, 2021, 8:17 AM UTC

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…

My take-away from veritsiums video was:

“What’s the point of the wire?”

- it’s not the length of the wire, it’s the distance between power source and consume that determines how fast power travels (how does power “know” where to go, if not following the wire?)

- since power travels outside the wire, it should be okay not to plug in the power consumer.

I’m pretty sure that’s completely and utterly wrong, but I don’t know what he is trying to say. So the video creates more confusion than it clears up.

> It kinda feels like most people are missing the actual point of the video.

Which raises an age old philosophical question about communication: who’s at fault for the misunderstanding: The sender or the receiver?

I’d say it’s a bad video because it is from a trusted source of science and most people misunderstand it.

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

#194

Post by nialv7 » Sat, Dec 18, 2021, 8:42 AM UTC

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…

Not answering your questions but I am so glad this "controversy" exists. I've learned so much more about this topic from all these response videos than I could have if there was no controversy.

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

#195

Post by blamazon » Sat, Dec 18, 2021, 8:49 AM UTC

zokier wrote: post #40

The thing that is most curious in this tempest in a teacup is why didn't Veritasium film this experiment themselves. It isn't particularly complicated or expensive setup, so it seems something that he definitely could have done. Instead he chose to leave the door open for the controversy that followed.

I wouldn’t have even heard about the Veritasium film if not for this response. Smart marketing play.

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

#196

Post by griffinheart » Sat, Dec 18, 2021, 9:05 AM UTC

I had a question about the veritasium video, at some point they say that the electrons barely move, that confused me since that doesn't match my understanding of amperage, flow of electrons being for example 6.24x10^18 per second.

Anyone care to help me out? Maybe that just isn't much?

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

#197

Post by elsjaako » Sat, Dec 18, 2021, 9:09 AM UTC

SAI_Peregrinus wrote: post #146

shukantpal wrote: post #137

Earlier quoted context omitted.

It should be obvious that the "c" here was used as a magnitude not with units. Saying that's "failing dimensional analysis" is in itself grossly sloppy - since it totally misses the context.

1m/cs is the correct value. Not 1/cs. The meters matters, hiding it makes it less obvious that the wire separation is what matters.

If you're going tot quibble about the units, it should be "1m/c". " 1m/c s" gives a result in s².

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

#198

Post by formerly_proven » Sat, Dec 18, 2021, 9:16 AM UTC

causi wrote: post #187

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…

He sets up the parameters so that the bulb would turn on by that little electricity That's the bit where he's factually wrong. He's made this illogical world where the tiny amounts of electricity in field lines well outside the wire trigger the lamp but the leakage current and other sources of current don't. If you're going to be pedantic about something you have to be pedantic about the whole thing, damn it. Veritas…

The experiment can be made to work (light bulb actually lighting up ~instantly at a significant brightness), just not with a 12 V bulb.

> Veritasium's video is like saying "water flowing through pipes is a LIE" because some molecules of water make it through the various seals and diffuse across the outer surface of the pipe.

Not at all.

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

#199

Post by elsjaako » Sat, Dec 18, 2021, 9:17 AM UTC

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…

The electrical charge travels through the wires. This causes an electrical field and a magnetic field surrounding the circuit.

The point is that the energy goes through the field, not through the wires.

In your example, the Poynting vector would go towards the resistor, where the energy is turned into heat.

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

#200

Post by formerly_proven » Sat, Dec 18, 2021, 9:21 AM UTC

zokier wrote: post #40

The thing that is most curious in this tempest in a teacup is why didn't Veritasium film this experiment themselves. It isn't particularly complicated or expensive setup, so it seems something that he definitely could have done. Instead he chose to leave the door open for the controversy that followed.

They didn't film it but

a) it's pretty trivial to do (I did it myself when the video was new because dangit a physicist kept sayin' I was wrong on the internet and that's UNACCEPTABLE)

b) there's a PDF in the description where one of the EE profs he asked did and gets exactly the same results as everyone else and also shows how easy it is to predict behavior of the experiment using line theory.