General > General Technical Chat

Kathy's Deep Dive Historical Response to Veritasium’s DC Electricity Video

(1/1)

ledtester:
Kathy of Kathy Loves Physics has produced a response video to the Veritasium circuit video.



It seems much of her critique involves an argument bout surface charges and the (mis-)interpretation of the Poynting vector. In the comments a person by the name of Eric L. Michelsen has this to say:


--- Quote ---... I think it is well established that the electric field inside a current carrying wire does, indeed, drive the current, and that this field is created by surface charges.  Conductors can expel E-fields only in a static (or quasi-static) system.  In contrast, a DC circuit is a steady-state dynamic equilibrium, and though the charges in the conductor move to reduce the E-field, the battery is constantly "pulling" them out of (and "pushing" them in) the wire, so they can never cancel the E-field completely.  It takes only a tiny E-field in a good conductor to drive a significant current.  This is established by extensive experiment, and organized into the detailed theory of electromagnetism (with no deference to anyone's authority).

I have a detailed discussion of the speed of electricity and the Poynting vector in my "Funky Electromagnetic Concepts" (at the bottom of my web page), starting around page 69 (as of this writing).   I performed (the moral equivalent of) Derek's experiment, and confirmed that in some very realistic situations (but not all situations), the bulb turns on nearly full brightness, nearly instantly (as expected from theory).  My document includes photographs of my setup and results, and a discussion of the theory, but is written at the upper-division college-physics level.  This is all well-established science, and fully consistent with relativity.  (In Dr. Muller's follow-up video, I think he actually didn't give himself enough credit for his prediction.)

--- End quote ---

His "Funky Electromagnetic Concepts" paper may be found at:

https://emichels.physics.ucsd.edu/FunkyElectromagneticConcepts.pdf

His discussion of the Veritasium video and Poynting vector begins on page 69.

Navigation

[0] Message Index

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod