General > General Technical Chat
"Veritasium" (YT) - "The Big Misconception About Electricity" ?
pepsi:
--- Quote ---All of this is irrelevant. He did the experiment and energy reached the load before it could travel the distance along the wires. End of story
Wires are not pipes.
--- End quote ---
Is this for real? Tell this to the national electricity grid. Let's get rid of poles and wires and beam MW of power to customers :-DD
Syndicate:
--- Quote from: bsfeechannel on May 01, 2022, 02:34:26 am ---All of this is irrelevant. He did the experiment and energy reached the load before it could travel the distance along the wires. End of story
Wires are not pipes.
--- End quote ---
What? The existence of some wireless transfer of power was never the issue. The problem is that the lamp doesn't turn on at "1/c seconds", and his explanations are off and misleading at best. "Wires are not pipes/Energy doesn't flow through wires" is good example of faulty conceptualization. And since the entire video rests on correcting conceptualization and the question of when the lamp turns on, that is a big problem for the video.
electrodacus:
--- Quote from: Sredni on May 01, 2022, 04:27:05 am ---You think that KCL holds, in the first few nanoseconds?
Oh dear, not another Kirchhoff battle...
--- End quote ---
Has significantly more energy left the battery than got to the load/lamp ?
Do you agree that energy conservation can not be violated ?
If so then any difference should have ended up as heat and or stored in some form.
If you will have a sensitive enough thermal camera you will see that all energy delivered to the Load/lamp was trough the wires (not outside the wires) as you will be able to see the IR losses (yes for those first few nanoseconds).
The load/lamp is basically in series with some capacitors (the long and most likely intentionally thick transmission line).
aetherist:
--- Quote from: electrodacus on May 01, 2022, 01:38:57 am ---
--- Quote from: aetherist on April 30, 2022, 11:55:25 pm ---Veritasium's scope screen looks sick.
--- End quote ---
That screen shows how much energy left the battery and how much energy arrived at the load (resistor).
Since current in that loop will be the same in battery and in resistor is clear to see that much more energy is delivered by the battery than dissipated on the resistor.
Where is that extra energy that battery delivered ?
Part of it is stored in the transmission line capacitance and inductance and part of it is lost as heat.
As stored energy is irrelevant as it did no work the lost energy will be in the form of heat.
All you need is a thermal camera and you can see that wires (copper pipe in this case) is what delivered the energy from battery to load.
That initial small current seen trough the load is due to energy being stored in the transmission line.
Not understanding what energy and energy storage is made Derek to come to a wrong conclusion about how energy is delivered from battery to load.
--- End quote ---
I aint an EE.
Q1. Once the current is steady, i guess that the area under the yellow V trace is less than the area under the input green V trace. Q1A. Duz the diff in area tell us the amount of heat lost? Q1B. Or duz the diff in area include energy making or sustaining em radiation?
Q2. Why did the rise in the green trace from 0.4V to 18.6V take 8.6 ns? Q2A. Why didn’t their (costly new u beaut) scope do it in say 1.0 ns, or even 0.1 ns?
Q3. Why didn’t Veritasium show us the initial pulses/rises with a 1.0 ns/div horizontal scale (ie as well as the 50 ns/div)? I suspect that the scope could do better than 0.1 ns/div (i think that the scope can give at least 20 GHz, which is better than 0.1 ns/div). This would have better shown us the 3.3 ns delay.
Q4. If the green rise took 8.6 ns, why did the yellow rise take 17.0 ns (ie from 4.1 to 21.2). Or 20.6 ns if u prefer (from 4.1 to 24.8 )?
Q5. Why did the green trace reach a steady state of 19.7V at say 300 ns, which is 1.0V lower than the yellow steady state of 20.7V at 300 ns? Even tho, early on (before 0.0 ns), the green trace sat at 0.4V while it was the yellow that sat 0.3V lower at 0.1V.
Q6. Why did the yellow trace start its main rise at 63.0 ns, when the speed of electricity along the 21 m Cu tube (10 m out plus 1 m spacing plus 10 m back) is 3.34 ns/m in air which demands that the rise should have been at 70.1 ns? A delay of 63.0 ns suggests a tube Cu length of only 18.9 m (2.1 m too short). Q6A. Why was the speed of electricity 10% faster than c?
electrodacus:
--- Quote from: aetherist on May 01, 2022, 04:54:40 am ---I aint an EE.
Q1. Once the current is steady, i guess that the area under the yellow V trace is less than the area under the input green V trace. Q1A. Duz the diff in area tell us the amount of heat lost? Q1B. Or duz the diff in area include energy making or sustaining em radiation?
Q2. Why did the rise in the green trace from 0.4V to 18.6V take 8.6 ns? Q2A. Why didn’t their (costly new u beaut) scope do it in say 1.0 ns, or even 0.1 ns?
Q3. Why didn’t Veritasium show us the initial pulses/rises with a 1.0 ns/div horizontal scale (ie as well as the 50 ns/div)? I suspect that the scope could do better than 0.1 ns/div (i think that the scope can give at least 20 GHz, which is better than 0.1 ns/div). This would have better shown us the 3.3 ns delay.
Q4. If the green rise took 8.6 ns, why did the yellow rise take 17.0 ns (ie from 4.1 to 21.2). Or 20.6 ns if u prefer (from 4.1 to 24.8)?
Q5. Why did the green trace reach a steady state of 19.7V at say 300 ns, which is 1.0V lower than the yellow steady state of 20.7V at 300 ns? Even tho, early on (before 0.0 ns), the green trace sat at 0.4V while it was the yellow that sat 0.3V lower at 0.1V.
Q6. Why did the yellow trace start its main rise at 63.0 ns, when the speed of electricity along the 21 m Cu tube (10 m out plus 1 m spacing plus 10 m back) is 3.34 ns/m in air which demands that the rise should have been at 70.1 ns? A delay of 63.0 ns suggests a tube Cu length of only 18.9 m (2.1 m too short). Q6A. Why was the speed of electricity 10% faster than c?
--- End quote ---
Q1. The graph shows voltage not power. You will need to calculate the similar graphs for power as the difference there will be way more significant about 25x vs just 5x
Then on those graphs the area under represents the energy.
Q2. They likely used a solid state switch and that has capacitance and can not close instantly. Not an oscilloscope problem.
Q3. It will not have been relevant. He anyway did not understood what it is actually seeing there.
Q4. speed electron wave is as fast as it is allowed in this universe.
Q5. Oscilloscopes are only accurate in time domain not that great as voltmeters.
Q6. I have not looked at the graph that closely and I do not know their exact setup and how accurate their length measurements where. But is also irrelevant.
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