General > General Technical Chat
"Veritasium" (YT) - "The Big Misconception About Electricity" ?
<< < (394/396) > >>
Sredni:

--- Quote from: TimFox on May 11, 2022, 10:03:31 pm ---If I remember correctly, there were different models (different characteristic impedance) to see what happens at discontinuities.
I think this old Mister Wizard demonstration uses the same unit.


--- End quote ---

That is John Shive with the... Shive machine.
Yes, it is the best way to learn about impedance matching and reflections.
Shive also wrote a wonderful book:

John N. Shive, Robert Weber
Similarites in Physics
1982, Wiley
273 pp.


--- Quote from: wikipedia ---He made notable contributions in electronic engineering and solid-state physics during the early days of transistor development at Bell Laboratories. In particular, he produced experimental evidence that holes could diffuse through bulk germanium, and not just along the surface as previously thought. This paved the way from Bardeen and Brattain's point contact transistor to Shockley's more-robust junction transistor. Shive is best known for inventing the phototransistor in 1948 (a device that combines the sensitivity to light of a photodiode and the current gain of a transistor), and for the Shive wave machine in 1959 (an educational apparatus used to illustrate wave motion).

--- End quote ---


aetherist:

--- Quote from: Sredni on May 11, 2022, 09:53:52 pm ---I resisted posting this since I didn't want to give wrong ideas to the 'original thinkers' in these threads, but since there already is some sort of discussion on how to mimic the behavior of the circuit with a mechanical model and the apparent necessity for an ether (in the mechanical representation) has already been thrown around, I figured... what the heck.
--- End quote ---
It reminds me of prep school & grade-1, where we used slate boards & slate pencils & wet sponge to wipe the slate clean.
Then in grade 3 we upgraded to inkwells. I never did do grade-2 – i jumped over it.
But i don’t see any need for an aether here in this gedanken nor in Veritasium's X.
HuronKing:
Hot damn that Dr. Shive video is amazing! I'm going to steal that for my classes.
aetherist:

--- Quote from: TimFox on May 11, 2022, 10:03:31 pm ---In high-school physics class, ca. 1965, we had a mechanical demonstrator for one-dimensional transmission lines that used a dense set of transverse rods connected to a central torsion spring.
One could propagate a pulse down the rods and see reflections.  Termination options included nothing (open circuit), fixed position (short circuit), and terminated (dashpot for viscous damping).
The propagation speed down the rods was appropriate for human eyesight to see the results.
If I remember correctly, there were different models (different characteristic impedance) to see what happens at discontinuities.
I think this old Mister Wizard demonstration uses the same unit.
--- End quote ---
What a wonderful youtube. I wonder how it applies to elekticity. How duz elekticity reflect off a deadend, or off a change in impedance.
Old (electron) electricity would have it that the drifting electrons are inside the wire. But i reckon that internal electrons contribute very little to electricity.
But my new (elekton) elekticity says that elektons play the major role in some cases.
What do elektons (photons) do when they get to a deadend?  They go straight ahead, koz that is what photons do.
The photons don’t reflect at the deadend, they do a u-turn & hence come back, no reflexion needed.
When i say that elektons do a u-turn i mean that the surface duz a u-turn, the photons don’t know, they are in the dark.

The mechanical analogy for impedance affecting the speed of a mechanical wave has no application in new (elekton) elekticity.
An elekton will propagate along the surface of the wire at a slightly slower than  c/1, due to the slowing/drag of the nearness of mass (& charge attraction).
This drag is of course moreso on the Cu side, hence the photon hugs the Cu.
However, the drag is a very local thing, it is only very slightly affected by Cu that is not local.
Hence the usual equations for impedance of a wire or a pair of parallel wires duz not affect the speed of elekticity, at least not the speed of elektonic elekticity.

When someone duz an X for the speed of elekticity along a bare wire & an insulated wire & a threaded rod, they can place lots of additional rods & wires close up & parallel to the wire being tested, & they will find that the speed of elekticity is not affected by additional wires etc, ie by additional impedance.
TimFox:
I have seen photons reflect from surfaces (dead ends) when doing photography.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod