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Veritasium -- How Special Relativity Makes Magnets Work.

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PlainName:

--- Quote ---One strike & i am out.
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https://www.eevblog.com/forum/chat/veritasium-(yt)-the-big-misconception-about-electricity/msg4043983/#msg4043983

aetherist:

--- Quote from: dunkemhigh on March 30, 2022, 11:17:00 pm ---
--- Quote ---One strike & i am out.
--- End quote ---
https://www.eevblog.com/forum/chat/veritasium-(yt)-the-big-misconception-about-electricity/msg4043983/#msg4043983
--- End quote ---
Yes, i see that there were about 14 postings (on that thread)(re Veritasium (YT)) re the Faraday Disc Paradox starting at my own reply #1457, & then a few more at #1669.
I will have to look into all of that later in the week. The aether explains the Faraday Disc Paradox, but then the aetherwind (500 km/s) creates a difficulty, but i think that i can find the answer (& avoid a strike).
Einsteinists reckon that GTR provides the answer to the Faraday Disc Paradox. I might look into that too, but for sure i wont understand it. Next week hopefully.

aetherist:
There are lots of (stupid) youtubes re the (stupid) STR cause of the mmf near a wire. They all briefly & quietly assert or infer that the electron spacings stay the same, ie before & after the current is switched on.  A disaster for STR.  I called it STRIKE-1, but that makes it look as if u are allowed a number of strikes – NO – one strike & the STR cause of mmf is out, that game is over.
And, if u think about it, STR is also out, that makes it two lost games, each has been struck out with the one pitch, its a case of killing two birds with one stone.  When i say STR is also out (falsified), i mean the length contraction part of STR (not the time dilation part).

Aetherists believe in length contraction due to velocity, the velocity of the aetherwind (not due to some stupid STR relative velocity). In the case of a wire conducting an electric current, the aetherwind or length contraction are not needed to explain anything (eg electric current, emf, mmf etc). However, the aetherwind will of course affect the electric fields etc, eg the aetherwind can (we know) slow electricity (if a headwind), or can fast electricity (if a tailwind)(as shown by DeWitte)(& Torr & Kolen).

The cause of mmf near a wire remains a mystery. Indeed emf remains a mystery. But electricity is no longer a mystery, it is due to (my) elektons (photons that hug the wire).

So, lets look again at what Purcell wrote….
In the lab frame of Fig. 5.22(a), with spatial coordinates x, y, z, there is a line of positive charges, at rest and extending to infinity in both directions. We shall call them ions for short. Indeed, they might represent the copper ions that constitute the solid substance of a copper wire. There is also a line of negative charges that we shall call electrons. These are all moving to the right with speed v0. In a real wire the electrons would be intermingled with the ions; we’ve separated them in the diagram for clarity. The linear density of positive charge is λ0.
It happens that the linear density of negative charge along the line of electrons is exactly equal in magnitude.
That is, any given length of “wire” contains at a given instant the same number of electrons and protons. 
[9] [9 It doesn’t have to, but that equality can always be established, if we choose, by adjusting the number of electrons per unit length. In our idealized setup, we assume this has been done.]
The net charge on the wire is zero. Gauss’s law tells us there can be no flux from a cylinder that contains no charge, so the electric field must be zero everywhere outside the wire. A test charge q at rest near this wire experiences no force whatsoever.

How can Purcell & Co justify [9]?  They can't. A disaster for the STR cause of mmf, & a disaster for STR, both killed with one stone.

TimFox:
A very important feature of magnetic forces in engineering is that very strong forces can be produced by running reasonable currents through conductors, especially when forming the wires into coils so that the same current contributes to the field over and over.  In normal constructions, it is hard to obtain very large electrostatic forces from charged metal objects.
Under normal conditions, matter in bulk is very, very close to electrically neutral, which means that the number of protons and electrons in the piece of bulk material are very, very, very close to equal.
In setting up his calculation, Dr Purcell starts out with a metal cylinder (wire) that is electrostatically neutral, to see what happens when a current runs through it.
What possible objection could there be to starting from that initial condition?

aetherist:
So, Purcell & Co say that the center to center spacings of drifting conduction electrons in a wire dilate when the current is switched on. Actually, that is a postulate, alltho Purcell & Co don’t give it that status. They know that raising it to the level of a postulate would be like waving a red flag, & they would rather sneak it into the conversation with zero fanfare. So here below is my version of this postulate (1). And i have composed & added a few other (mostly implicit) postulates (some good)(some bad)(some ugly).

POSTULATE (1). The electron to electron (center to center) spacings (of drifting conduction electrons in the wire)(measured along the wire)(measured in the wire frame)(ie the lab frame) stay the same, ie before & after the current is switched on. (2) These spacings are the same as the Cu atom spacings (ie the proton spacings)(measured along the wire).  (3) Hence the wire is charge neutral, before & after the current is switched on (in the wire frame)(ie the lab frame).  (4) The current is due to electrons being injected into the wire (at say one end).  (5) For a steady state current, electrons are ejected from the wire (at the other end).  (6) There is some kind of automatic natural process whereby the injection & ejection rates ensure that the number of drifting electrons equal the number of (say Cu) atoms in any length of wire (at least for a steady state current).  (7) The auto process in (6) automatically takes into consideration the Einsteinian (STR) length contraction of the spacings, such that the injection rate reduces (or something).  (8 ) The auto process in (6) also automatically offsets the contraction-compression of the electron spacings that arises due to the forces needed to drive the electric current (ie push the electrons) along the wire.  (9) Some of the force & energy of the compression in (8 ) is of course needed to overcome the electrical resistance, & (10) it heats the wire.

POSTULATE (11).  All conduction electrons participate in the current, ie they all drift, & (12) the average drift velocity is often very slow (eg 0.02 mm/s).  (13) The length contraction of electron to electron spacings involves the ave drift velocity, ie (14) it duznt matter that most drift slower or faster most of the time, (15) it duznt matter that the thermal motion of a Cu atom (& hence the thermal motion of conduction electrons) is about 200 m/s (ie 10,000,000 times the drift velocity).  (16) The length contraction of proton to proton spacings involves the ave drift velocity of the electrons, (17) it duznt matter that a Cu nucleus (& the protons in the nucleus) have a thermal speed of say 200 m/s, (18) & it duznt matter that protons in a Cu nucleus have a high vibratory motion (say 1000 m/s)(needs checking). (19) It duznt matter that the thermal or vibrational etc motions are in the opposite direction to the drift velocity a half of the time.  (20) Motions across the wire do not matter (in the simple case today), koz STR length contraction only applies to the xx direction (not the yy or zz directions).  (21) Electrons have to travel much further koz they have to pass around atoms etc, but this extra distance & (22) the extra speed needed are automatically included in the calculation of ave drift velocity.

POSTULATE (21).  The Coulomb force (or Lorentz force) experienced by the test charge (say electron) moving at the drift velocity (or at some other velocity) needs to be converted to the equivalent force in the stationary lab frame.  (22) This conversion requires the application of the Einsteinian gamma, (23) giving a lesser force in the lab frame.

STR POSTULATES.  STR says that space contracts, & hence that everything in that space contracts, eg electrons contract, the spacings tween electrons contract, the gaps tween electrons contract. But Einsteinists don’t agree (with each other) re length contraction. U might notice that Derek (Veritasium) in his youtube says that the spacings appear to contract (he uses the term perceived spacings). While Nick (The Science Asylum) says that the spacings actually contract. Einsteinists probly don’t care whether contraction is real or just apparent.  I can't remember what Einstein thort.

Funny, i saw a comment in a youtube that said that a Professor said that when the electricity is switched on that the drifting electrons contract but that the spacings did not contract. The Prof said or implied that objects contract but spacings don’t. The Prof said that when the wire has a relative velocity then the wire suffers length contraction, ie proton to proton spacings are contracted. But if the wire is stationary then the spacings of drifting electrons dont change, no matter how fast they drift. I suppose that that explanation works, but i think that it violates the standard (Einsteinian) version of STR.  I know that Einstein hizself said that individual electrons are length contracted, but Einstein did not ever (that i know of) mention a case where spacings or gaps were not length contracted.

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