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| ejeffrey:
--- Quote from: electrodacus on May 11, 2022, 05:33:29 pm --- --- Quote from: TimFox on May 11, 2022, 05:28:44 pm ---Of course, in vacuum, electron beams flow quite nicely. In air, they flow less nicely in the form of arcs, sparks, and lightning. --- End quote --- The amount of energy flow through air can be ignored in Derek's experiment due to super low potential 20V and large gap 1m between the two conductors. --- End quote --- Can you *calculate* how much? Because I can using classical electrodynamics, and it agrees with what Derek showed and also his original thought experiment with wires going to the moon. Both versions show that an appreciable fraction of the steady-state power can be transferred before the ends of the wire are causally relevant. The exact amount depends on the load and the wire spacing. The only part I can't "calculate" is the cutoff where I stop saying that the energy is transferred through space and it starts being transferred via the wire. That is because no such cutoff actually exists, and the practice of doing so is a convenient low frequency approximation of electrodynamics that can explains some but not all circuit phenomena. |
| electrodacus:
--- Quote from: ejeffrey on May 11, 2022, 06:10:03 pm --- Can you *calculate* how much? Because I can using classical electrodynamics, and it agrees with what Derek showed and also his original thought experiment with wires going to the moon. Both versions show that an appreciable fraction of the steady-state power can be transferred before the ends of the wire are causally relevant. The exact amount depends on the load and the wire spacing. The only part I can't "calculate" is the cutoff where I stop saying that the energy is transferred through space and it starts being transferred via the wire. That is because no such cutoff actually exists, and the practice of doing so is a convenient low frequency approximation of electrodynamics that can explains some but not all circuit phenomena. --- End quote --- If you did not already check this post I made yestarday https://www.eevblog.com/forum/chat/veritasium-how-electricity-actually-works/msg4168171/#msg4168171 |
| vad:
--- Quote from: electrodacus on May 11, 2022, 06:08:38 pm ---Where do you see broken law of conservation of energy in any of my statements ? And how what I said has nothing to do with reality when that is exactly what you see in reality including Derek's experiment. --- End quote --- You claim that in addition to energy that is flown away from battery by electromagnetic field (that an average STEM undergrad can compute using Poynting vector and calculus at least for DC case), there is additional flow of EM energy inside wire along its axis. This additional energy can’t come from the battery, because all battery energy either flows inside the wire perpendicular to its axis causing Joule heating, or flows outside wire towards load, as can be show by STEM uni student. So this additional EM energy that you claim flows inside wire along its axis comes from nowhere, and further discussion should move to “over unity” section of this forum. |
| electrodacus:
--- Quote from: vad on May 11, 2022, 06:39:30 pm --- --- Quote from: electrodacus on May 11, 2022, 06:08:38 pm ---Where do you see broken law of conservation of energy in any of my statements ? And how what I said has nothing to do with reality when that is exactly what you see in reality including Derek's experiment. --- End quote --- You claim that in addition to energy that is flown away from battery by electromagnetic field (that an average STEM undergrad can compute using Poynting vector and calculus at least for DC case), there is additional flow of EM energy inside wire along its axis. This additional energy can’t come from the battery, because all battery energy either flows inside the wire perpendicular to its axis causing Joule heating, or flows outside wire towards load, as can be show by STEM uni student. So this additional EM energy that you claim flows inside wire along its axis comes from nowhere, and further discussion should move to “over unity” section of this forum. --- End quote --- Have you seen the post where I made the Spice simulation showing energy output from the source and the energy at the lamp/resistor ? https://www.eevblog.com/forum/chat/veritasium-how-electricity-actually-works/msg4168171/#msg4168171 You have a wrong understanding of what energy is and how it is transferred from source(battery) to load (lamp/resistor). The graphs I posted there for two cases show exactly how energy travels. Also an incandescent lamp is nothing more than a wire with higher resistance so is the 1KOhm resistor Derek used in his experiment. |
| vad:
--- Quote from: electrodacus on May 11, 2022, 06:55:56 pm --- Have you seen the post where I made the Spice simulation showing energy output from the source and the energy at the lamp/resistor ? https://www.eevblog.com/forum/chat/veritasium-how-electricity-actually-works/msg4168171/#msg4168171 You have a wrong understanding of what energy is and how it is transferred from source(battery) to load (lamp/resistor). The graphs I posted there for two cases show exactly how energy travels. Also an incandescent lamp is nothing more than a wire with higher resistance so is the 1KOhm resistor Derek used in his experiment. --- End quote --- You are using wrong tools. Spice by no means can be used to simulate electromagnetic field in matter and space. Also, at DC, you did not have to go that far by drawing what looks like a transmission line. 3 resistors (one for load and two for each wire), a battery and a ground symbol are sufficient for DC analysis in Spice. |
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