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"Veritasium" (YT) - "The Big Misconception About Electricity" ?
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aetherist:

--- Quote from: adx on February 12, 2022, 10:58:57 am ---
--- Quote from: aetherist on February 12, 2022, 10:08:29 am ---No wave of any kind can propagate at a velocity of any kind unless the medium moves at least briefly at that velocity or more.

--- End quote ---
How does a wave travel at its normal velocity when amplitude is reduced indefinitely?

--- End quote ---
I dont understand. But i am talking about longi (axial) velocity not normal (transverse) velocity.
penfold:

--- Quote from: aetherist on February 11, 2022, 09:48:55 pm ---[...]
Is this the same IEEE that would not let Heaviside publish in their journal?
Is this the same IEEE that called Heaviside a crackpot when he came up with his equations?
Is this the same IEEE  that conceded that his equations worked when they fixed the telegraphy cable?
[...]

--- End quote ---

The biggest takeaway here is not that the IEEE were wrong to reject Heaviside, but that the process and progression of scientific understanding at its very core does not and should not look particularly fondly on logical jumps without sufficient evidence.

Seeing as you mentioned quaternions, I find it very difficult to believe that somebody favouring the GA representation of Maxwell could disregard relativity and Einstein-ism... surely sticking with vectors and tensors is the way to go if you're avoiding Einstein? The whole concept of space-time is baked right in there with GA isn't it? Do you have an alternative formulation, because that could be interesting?
adx:

--- Quote from: aetherist on February 12, 2022, 11:12:05 am ---
--- Quote from: adx on February 12, 2022, 10:58:57 am ---
--- Quote from: aetherist on February 12, 2022, 10:08:29 am ---No wave of any kind can propagate at a velocity of any kind unless the medium moves at least briefly at that velocity or more.

--- End quote ---
How does a wave travel at its normal velocity when amplitude is reduced indefinitely?

--- End quote ---
I dont understand. But i am talking about longi (axial) velocity not normal (transverse) velocity.

--- End quote ---
A stick. Quite a long stick. Poke at something fairly rigidly fixed but moves a little. Time how long it takes from pushing until the movement reaches the other end. Now this is complicated by the slowness of the motion needed to demonstrate that slow movement of the medium is translated to fast effect at the far end, but you could time it from peak to peak, or look for a percentage rise at the leading edge. Or simply calculate the max velocity of the medium and expected arrival time of the effect from the statement that the propagation velocity cannot exceed that of the medium's peak velocity. But that may be unsatisfying because it removes the stick from the system.

That's why I asked the question I did: Halve the amplitude of your poking, which halves the peak velocity of the medium. Does it reduce the propagation velocity? No. Ok halve it again, until you see the propagation velocity slow as you predict (when the medium is moving too slowly to support the propagation velocity you first saw). At some point the signal will become lost in noise or measurement precision, but until that point, conventional wave theory says the propagation velocity will not change in a linear medium like a stick. There is no identifiable point where it slows, down to (nearly) zero medium velocity.

Your idea might have more relevance when the propagation velocity is the speed of light.
SandyCox:

--- Quote from: aetherist on February 12, 2022, 11:08:22 am ---
--- Quote from: SandyCox on February 12, 2022, 10:51:47 am ---https://archive.org/details/ThePhysicsOfVibrationsAndWavesH.J.Pain/page/n15/mode/2up

--- End quote ---
That looks to be a dy/dt transverse particle velocity, not a dx/dt.

--- End quote ---

Exactly! The particle and wave velocities are not equal.

"
The particle velocity ... is therefore given as the product of the wave velocity
...
and the gradient of the wave profile preceded by a negative sign for a right-going wave
...
"

I suggest that you read the whole chapter. Its quite an eye opener.
adx:
Placeholder for "(b)ah, phonons". Momentum, aether.
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