Amps X Voltage = Watts
- Feb 16, 2020
Too much foe me to comprehend
The whole water flowing through pipes analogy still holds.
I'm not sure what would be pseudoscience in this video, but it also doesn't know what would constitute (as the title suggests) a "misperception" about electricity?Veritasium is known to be the click-bait of science and does a lot of pseudoscience-like logic in other videos so I would take this video was a truckload of salt. Honestly, he just discovered RF & maybe capacitance. The whole water flowing through pipes analogy still holds.
That's exactly what they're trying to imply.Maybe Veritasium is trying to make us think that the electrical power travels only through the Poynting flux and not through the wires?
Being correct on a technicality means you've to dive into minute details of the argument which is the opposite of simplifying assumptions. I bet those there professors of EE would have serious problems with the final video...Veritasium did warn that some "reasonable" simplifying assumptions must be made which leaves a lot of wiggle room for interpretations, but it is apparently enough to draw into question the final results from 4 Professors of EE.
There's a bunch of sleight of hand that is just meant to distract.So if there is a pseudoscience, it is in his somewhat "sleight of hand" in going from well-understood science (Ohm's, Maxwell and Poynting), to the surprising 3-dimensional integrated view in an electrical circuit, but then adding in some relativistic factors about very long lengths of wire with zero capacitance, inductance, and resistance (as corresponding simplifying assumption??).
Maybe "physical process" isn't the term I'm looking for. I think what I'm trying to say is energy flow in itself isn't a physical process but a measure of the change in a quantitative property caused by physical process if that makes any more sense.Say what?
You're correct energy is a quantitative property and the flow of energy is a change in that quantitative property over space and time.In physics, energy is the quantitative property that must be transferred to a body or physical system to perform work on the body, or to heat it. It most definitely is a physical process.
Agree that it is very misleading. The electromagnetic properties are being looked at separately which is fine in a technical argument but will give people the wrong impression of how this would work in a practical sense.If you add two more switches to the circuit at opposite ends where the wire bends - and open those two switches half a second before you flip the main switch - you'll still see some RF (+ maybe capacitance?) induced voltage at the bulb even thought the circuit is incomplete.
Again, I find this video extremely misleading. It's correct on a technically but it doesn't state it that way. Instead it states it in the way that "electrical energy doesn't flow through wires."
I also want to mention that the video did a qualitative analysis of energy flow instead of a quantitative one. In the other words, that 3D diagram reflects direction of the fields and the Poynting vector with no analysis of the magnitudes. They then go on to suggest that majority of energy flows through free space outside the wiresenergy is the quantitative property
I think the notion that we understand the underlying physical processes is a fallacy. Even if we are the best-known model in quantum mechanics and string theory we don't know the exact physical process we only have models of these processes. Ohms law is one such model as are Maxwell's and Poynting's. Arguing that energy is transferring via a field theory and not via a circuit is as fundamentally flawed as arguing the reverse (i.e. energy is transferred via current flow and not through a field).I also want to mention that the video did a qualitative analysis of energy flow instead of a quantitative one. In the other words, that 3D diagram reflects direction of the fields and the Poynting vector with no analysis of the magnitudes. They then go on to suggest that majority of energy flows through free space outside the wires
My mind is not blown by the physics but by how this graphical representation so precisely matches one of the most fundamental innermost models of our most formal logic (i.e. the propositional calculus).
True but they're using Poynting vector for something it doesn't describe. It's not a breakdown of that model. It's a misuse.To wrap this up it would seem that in general there will always be a breakdown in our models under some condition requiring a more general model (at least until a Theory of Everything is developed). But within their respective regions of application, models such as Ohm's, Maxwell's, and Poynting do apply to real processes and one is not to be applied as "the only answer" to the exclusion of the others.
I'm not sure why you think the Poynting vector does not apply in general? The vector is the basis for the Poynting Theorem which is an energy balance in terms of the vector. The theorem does not only apply to free space.True but they're using Poynting vector for something it doesn't describe. It's not a breakdown of that model. It's a misuse.
The Poynting vector needs to be integrated over a closed surface of a volume in 3D space to be used in the Poynting theorem.The rate of energy transfer (per unit volume) from a region of space equals the rate of work done on a charge distribution plus the energy flux leaving that region.
A second statement can also explain the theorem - "The decrease in the electromagnetic energy per unit time in a certain volume is equal to the sum of work done by the field forces and the net outward flux per unit time".
Isn't the light an energy sink? I would assume that the graphic was generated from a numerical integration package that would compute the fields from an idealized circuit.The Poynting vector needs to be integrated over a closed surface of a volume in 3D space to be used in the Poynting theorem.
Yes there's non-zero Poynting vectors outside the wires and yes there shouldn't be any vectors inside the wire (assuming ideal conductors, etc). But I don't know what you can conclude from that without drawing a volume somewhere and integrating the vectors over the closed surface of that volume. If you do that outside the wires... you should get zero. If you do that inside or including the wire... you should get zero. It should be zero unless you include an electromagnetic energy source or sink inside the volume.
Are you talking about the 3D graphic from the original video? It most likely wasn't created that way...Isn't the light an energy sink? I would assume that the graphic was generated from a numerical integration package that would compute the fields from an idealized circuit.
Trying to interpret the Poynting vector as something it's not.You said before "It's a misuse." Where or what it's abusing the model?
Unfortunately, I think this your example is getting away from any point I can absorb.onsider this example: wrap the entire circuit lo