Tesla's ether theories and longitudinal waves explained in "Wardenclyffe"

[Ernst]

The "condensing" of electricity into electrical charge idea needs further thought, IMHO. From my point of view, "charge" is a property of certain particles, which appear to emit a Tesla wave at a specific, characteristic frequency. This is distinctly different from Maxwell's idea of displacement current and charges, spatial "charges". Charged particles are real entities, which cause a certain pressure to be present in the medium because of their oscillation and emission of a Tesla wave. By considering the wave itself to also involve oscillating "charge", you are conceptually mixing things up. Along Huygens' principle, it is not wrong to consider any point in the space a propagating Tesla wave propagates trough as being "charged", but it adds a certain complexity to the picture that is unecessary, as far as I can tell.

In the model I described here, any electrical effect, including charge is NOT a property of ANY particle. Electricity is a medium that, through its interaction with matter causes apparent charge. The presence of matter withing this medium can cause a change in this medium that we commonly refer to as an electric field. This field is centred around a particle, but the particle barely plays any role in it. Electricity ("the medium" in Tesla's writings) clings to matter, as Tesla describes it.
In the Earth, being a large lump of matter, there is a lot of electricity (read "gaseous medium immersed in the ether") because of pressure from solar radiation among other cosmic causes, some of this electricity gets displaced into our atmosphere, not bound to any matter. A shockwave caused by a discharge of more than a million volts (I do not know the exact minimum required potential, but it is near 1 MV) can "condense" this electricity onto gas molecules (ionize) thus creating an electrical charge. This is the reason why discharges of such voltages can bridge distances far greater than the usual 1 meter per 1 MV. (see lightning; stepped leader)
The interesting bit now is, that you don't need to have a single 1MV discharge, but with the sawtooth modulated on an RF high potential, you can do the same thing, splitting the one big step into many smaller steps as it were. (see QCW Tesla coil)

You really, really need to see our book. I can offer it to you for 30 EUR if you pay to my Dutch bank account or in crypto or paypal.
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I can make the same offer to anyone in Europe or the US, in the US perhaps Kyle can offer more options
Drop me a PM if you are interested.
(you should be!!! )

Ernst.

[kyle_dellaquila]

Awe, thank you for the birthday wishes
It is truly wonderful to have my first posts on the Energetic Forum be on such a mind expanding thread/conversation.
As this thread will continue, I will do my best at illustrating the areas of interest. Correct me if anything appears misleading to the visual interpretations..

Electric phenomena:
1) State
2) Effect

In terms of electric effects:
1) Opposite in character
2) Neutralizing each other
ZSUFIa0.png
TwbtHOj.png

"If we speak of electric effects we must distinguish two such effects, opposite in character and neutralizing each other, as observation shows that two such opposite effects exist. This is unavoidable, for in a medium of the properties of ether, we cannot possibly exert a strain, or produce a displacement or motion of any kind, without causing in the surrounding medium an equivalent and opposite effect. But if we speak of electricity, meaning a thing, we must, I think, abandon the idea of two electricities, as the existence of two such things is highly improbable. For how can we imagine that there should be two things, equivalent in amount, alike in their properties, but of opposite character, both clinging to matter, both attracting and completely neutralizing each other?
[...]
If there is such a thing as electricity, there can be only one such thing, and; excess and want of that one thing, possibly; but more probably its condition determines the positive and negative character."

-Nikola Tesla

What is that condition?
(option A) Is it the variations of "medium" density that defines the opposite character?
(option B) or does the medium clump around matter regardless of the polarity.
1qe48Jf.png
CDUo8Pk.png
Ernst & Tesla are suggesting that this "medium" is of a gaseous nature comprised of neutral particles and should follow the "ideal gas law".
WCcMPHd.png
If electricity is of a gaseous medium, one would be able to abstract electricity/heat from the surrounding environment.
0sTWFiL.png
-Kyle Dell'Aquila

[Ernst]

Two experiments (almost) anyone can do (at your own risk! I am not accepting ANY responsibility for experiments that anyone does even if inspired or even suggested by me in this thread!):
1
A high voltage capacitor is kept under a very thin oil and charged to its maximum potential, then discharged through a magnetically quenched spark gap. (I have tried with a normal spark gap without success, it had to be a magnetically quenched gap). While the capacitor discharges hold a conductive rod near the oil surface (not touching the oil) and you will see circular waves on the oil surface centred around the tip of the rod. A non-conductive rod has no effect, a conductive rod produces the waves.
Why? The electricity moving in and out of the capacitor drags air molecules along, creating small pushes on the oil surface. When a conductor is held near the electricity prefers to follow the conductor. Thus near the tip of the conductor, the pushes are much stronger than in other places on the surface. As you can imagine the leads of the capacitor can also cause waves that will distort the visibility of this effect. To avoid that I used aluminium strips clamped to the glass container (also to avoid movement).
This also shows that (most) electricity flows along conductors, not through.
2
Take a Tesla coil and an IR-thermometer. Measure the temperature of or near the top-load.
while doing so, switch the coil on. Electricity now gets compressed and thus rises in temperature. You should measure a short temperature spike while switching on.
While the coil is on the thermometer will return to the same value it showed when the coil was switched off.
Now, switch the coil off. Electricity now expands and cools. You should see a short-lasting temperature drop.
This confirms
- that electricity follows the ideal gas law
- (option B) or does the medium clump around matter regardless of the polarity. (see Kyle's post above)

Remember our (temporary) promotion:

SPECIAL Energetic Forum Offer
The book "Wardenclyffe" for only 30 EUR
if you live in Europ or the US and pay to my Dutch bank account or in crypto or paypal.
Drop me a PM if you are interested.


Ernst.

[kyle_dellaquila]

A conductive point producing displacement in oil when a sudden discharge occurs beneath the oil regardless of polarity:
282QNRe.jpg
An infrared thermometer pointing at a coil. Note the momentary raise in temperature when the coil is switched on (in constant-wave) and then switched off:
nyAPa6z.png
Low versus high frequency – the medium accumulating/clumping around around the terminal regardless of the polarity:
10H3KDb.png
HI0nYFW.png

-Kyle Dell'Aquila

[lamare]

In the model I described here, any electrical effect, including charge is NOT a property of ANY particle. Electricity is a medium that, through its interaction with matter causes apparent charge. The presence of matter withing this medium can cause a change in this medium that we commonly refer to as an electric field. This field is centred around a particle, but the particle barely plays any role in it. Electricity ("the medium" in Tesla's writings) clings to matter, as Tesla describes it.

What IS charge?

Paul Stowe found a relation between the charge of a particle and it's mass. This ratio yields a (characteristic) frequency along:

f = q / m.

This relation seems to hold for the electron, given the frequency for the electron seems to match observed cosmic microwave background, apart from red shift. I'm beginning to doubt it also holds for the proton, but the idea is that a "charged" particle oscillates longitudinally. It rythmically contracts and expands and thus emits a longitudinal superluminal Tesla wave in the medium, the aether. And because one cannot have negatieve frequencies, "charge" cannot be polarized.

Now since the result of the presence of a "charged" particle is the presence of such a longitudinal "sound" wave in the aether, along Huygens' principle one can see that as (distributed) "apparent charge". And an electric field then simply IS such a longitudinal Tesla "sound" wave. This way, one does not need to consider electricity itself as a separate medium.

One can see a "charged particle" as a sort of antenna for longitudinal waves, both receiving and transmitting these Tesla waves at the same time. Thus, charged particles do not emit a sound-wave whereby the energy needed to do so comes out of nowhere, but exchange energy continously across the Universe by means of resonance.

So, charged particles have a characteristic oscillation frequency that is a property of such a particle, while "charge" itself is an electrical effect, namely the presence of a Tesla wave and associated contractions/expansions of the medium. Thus, charge itself is indeed not a property of any particle nor of the medium, the aether.


It does seem that both these longitudinal waves as well as it's electromagnetic counterpart is guidable along a conductor, so their indeed seems to be an effect that "clings to matter", or better: "material".

In the Earth, being a large lump of matter, there is a lot of electricity (read "gaseous medium immersed in the ether") because of pressure from solar radiation among other cosmic causes, some of this electricity gets displaced into our atmosphere, not bound to any matter. A shockwave caused by a discharge of more than a million volts (I do not know the exact minimum required potential, but it is near 1 MV) can "condense" this electricity onto gas molecules (ionize) thus creating an electrical charge.

This is where things get tricky. You equate electricity to a "gaseous medium", which thus necessarily consists of some kind of particles, which must adhere to the wave-particle duality principle if they are to be real particles and thus one obtains a nice can of worms to sort out. Why the desire for a "gaseous medium" on top of the medium we already have, the aether?

This is the reason why discharges of such voltages can bridge distances far greater than the usual 1 meter per 1 MV. (see lightning; stepped leader)
The interesting bit now is, that you don't need to have a single 1MV discharge, but with the sawtooth modulated on an RF high potential, you can do the same thing, splitting the one big step into many smaller steps as it were. (see QCW Tesla coil)

This is definately an interesting phenomenon.

You really, really need to see our book. I can offer it to you for 30 EUR if you pay to my Dutch bank account or in crypto or paypal.
SPECIAL Energetic Forum Offer
I can make the same offer to anyone in Europe or the US, in the US perhaps Kyle can offer more options
Drop me a PM if you are interested.
(you should be!!! )

Ernst.

My birthday is coming up at the end of the month. Usually, I don't have a wish list since I don't know what to ask. This year, I've got three books on my wish list, all by the same author.

[lamare]

Awe, thank you for the birthday wishes
It is truly wonderful to have my first posts on the Energetic Forum be on such a mind expanding thread/conversation.
As this thread will continue, I will do my best at illustrating the areas of interest. Correct me if anything appears misleading to the visual interpretations..

Electric phenomena:
1) State
2) Effect

In terms of electric effects:
1) Opposite in character
2) Neutralizing each other
ZSUFIa0.png
TwbtHOj.png

"If we speak of electric effects we must distinguish two such effects, opposite in character and neutralizing each other, as observation shows that two such opposite effects exist. This is unavoidable, for in a medium of the properties of ether, we cannot possibly exert a strain, or produce a displacement or motion of any kind, without causing in the surrounding medium an equivalent and opposite effect. But if we speak of electricity, meaning a thing, we must, I think, abandon the idea of two electricities, as the existence of two such things is highly improbable. For how can we imagine that there should be two things, equivalent in amount, alike in their properties, but of opposite character, both clinging to matter, both attracting and completely neutralizing each other?
[...]
If there is such a thing as electricity, there can be only one such thing, and; excess and want of that one thing, possibly; but more probably its condition determines the positive and negative character."

-Nikola Tesla

What is that condition?
(option A) Is it the variations of "medium" density that defines the opposite character?
(option B) or does the medium clump around matter regardless of the polarity.
1qe48Jf.png

(option C) Polarity is not a (primary) electric effect, but either magnetic in nature or the result of standing longitudinal waves.


I posted some video's a couple of days ago, a/o involving experiments with "static" charged objects as well as with sound waves, the analog of Tesla waves in the aether. The experiment with a balloon and a loudspeaker shows that one can have an attractive force due to longitudinal waves under particular circumstances.

The current interpretation of experiments with "statically charged" objects is that two kinds of charges exist, which are called positive and negative. Obviously, these macroscopic experiments need to be explained, but that in no way implies that we need to have two kinds of "charge" at the fundamental level. In fact, it is the insistence that there must be two fundamental types of "charges" that prohibits the consideration that the aether simply is a kind of gas/fluid like medium that has a certain mass density (currently called "electric permittivity") and a certain viscosity (currently called "magnetic permeability").

When we let go of the idea that charge is fundamentally polarized and consider that the only way one can have "distinguishable entities" (wave-particle duality) within a fluid-like medium is by means of vortex rings, the conclusion that particles must consist out of a number of vortex rings is almost unescapable. And since a vortex ring has two axes of rotation, it can give rise to two kinds of polarity, which are thus magnetic and not electric in nature.

This way, the polarity problem can be resolved, without getting into trouble with having an electrical neutral medium, the aether.

CDUo8Pk.png

Note that in the right picture, there are +'s en -'s. This can just as well be relative to the background (pressure), like X+y and X-y.

Also, the details of what "current" is, is a lot more complex than just having "charge carriers" flowing trough a wire. In fact, at higher frequencies most of the energy flows in the space surrounding the conductor (where there are no "charge carriers") and Elmore has shown it is even possible to have a guided EM wave such that "real" current density is actually zero, thus yielding a very low loss method of transmitting energy and/or information:

http://www.tuks.nl/pdf/Patents/Elmor...0Conductor.pdf

Furthermore, since according to (the original formulation of) Ampere's law, "current density" is (proportional to) the curl of the magnetic field [B] and Tesla's longitudinal wave is like a sound-wave that has no rotation/curl and therefore no magnetic field, it by definition has no "current density", so in that case the idea that these kinds of waves are directly caused by c.q. consist of movements of "charge carriers" actually makes no sense at all.

Ernst & Tesla are suggesting that this "medium" is of a gaseous nature comprised of neutral particles and should follow the "ideal gas law".
WCcMPHd.png
If electricity is of a gaseous medium, one would be able to abstract electricity/heat from the surrounding environment.
0sTWFiL.png
-Kyle Dell'Aquila

The interesting thing is that this would go for the aether itself as well, given that it is found to behave like a gas/fluid.

[Ernst]

I cannot say more about the exact nature of electrical charge than
- it is an effect in the medium (electricity) surrounding a particle caused by an interaction between this medium and the particle
what the exact nature of this interaction is I have not yet been able to figure out.
But I do subscribe to the idea that charge comes in two polarities, positive and negative. If that weren't the case, two highly positively charged conductors, one slightly higher than the other should attract, because the lower charged one could be seen as negative with respect to the higher charged one. We know that that doesn't happen.
Similarly, two equally charged objects should neither attract or repel each other since one has a zero potential with respect to the other.

The videos that you posted showing how objects can be held in fixed positions, do not explain attraction or a repelling action. Only fixation. Therefore, in my opinion, the Stowe wave theory doesn't work.
But the universal resonance theory does have a certain attractiveness, I must admit.

Yes, there is a tricky thing going on with the "gaseous medium particles" and other particles. These are fundamentally different things. But the particle-wave duality is not really a thing. Particles are like whirls in the fluid ether, so they are an effect, much like charge. Let's look at an electron. It is a tiny particle surrounded by a giant electric field. This electric field stretches miles, light years even. In the case of a single electron the strength of the field gets immeasurably small over some macroscopic distance, but put a few trillion-trillion electrons together and it becomes measurable.
This electric field has a strong interaction with a particle, but not necessarily the entire time with the same particle. (Tesla writes that he does not believe in what we today call "an electron") Likewise, an electric current does not involve tiny particles moving through a wire. It is the surrounding effect that moves along the wire. In a double-slit experiment the effect moves through both slits and "re-attaches" to a particle later on (collapse of the wave function).
This is a very "hairy" subject that could fill an entire thread with 100's of posts. I don't want to stray too far from the subject and purpose of this thread. But one more thing to ponder about:
The fact that every material no matter its composition or structure radiates the same black body radiation only dependent on its temperature is a sign that this must originate from a very fundamental level. There is an explanation involving photon-gas. My IR-thermometer experiment above appears to link "the medium" to this photon gas.

In Tesla's lecture of February 1892 "Experiments with Alternate Currents of High Potential and High Frequency" Tesla explains how he came to the conclusion that electricity must be a gaseous medium. You probably have the text of that lecture but just to bring some variety to your wish list; there is a beautifully illustrated version of that lecture available.

My birthday is coming up at the end of the month. Usually, I don't have a wish list since I don't know what to ask. This year, I've got three books on my wish list, all by the same author.

Mmm, it sounds like that maybe an author very familiar to me... perhaps even close... Perhaps even very close... If so, I can get you a discount on all three of them...

If you look at Maxwell's work where the ε-naught comes from, you'll find it is from -1/k where k is a spring-constant representing the elasticity of a solid medium. To equal that to the viscosity of a liquid is a bit of a stretch in my opinion.


Ernst.

[Ernst]

One of the things I would like to explore here with the help of anyone who is interested, is how to detect these longitudinal waves in the medium.
I have an idea that Tesla did this with a coherer and that that is actually how a coherer works. Today you can obtain very fine nickel powder, made in some chemical process, and I think with that one could make a new generation of coherers. I did some tests with filings from various metals and found that nickel works the best by far.
But so far I have used filings. Now I have this very fine nickel powder, so I will make and test a coherer with that.

I have also been contacted by soundiceuk as he plans to replicate the rotating brush experiments. That would also be fantastic!
But from what I read I get the impression that this rotating brush responds to magnetic effects and not so much Tesla's longitudinal waves.
Nevertheless, it would be very exciting to play with this for a while and see what it does!


Ernst.

[lamare]

If you look at Maxwell's work where the ε-naught comes from, you'll find it is from -1/k where k is a spring-constant representing the elasticity of a solid medium. To equal that to the viscosity of a liquid is a bit of a stretch in my opinion.

ε-naught describes the permittivity:

https://en.wikipedia.org/wiki/Permittivity

That's the one related to mass density of the aether denoted by ρ, which is strongly related to pressure for gases, so it is akin to the elasticity of a solid medium:

https://en.wikipedia.org/wiki/Densit...ges_of_density

[T]he density of gases is strongly affected by pressure. The density of an ideal gas is

where M is the molar mass, P is the pressure, R is the universal gas constant, and T is the absolute temperature. This means that the density of an ideal gas can be doubled by doubling the pressure, or by halving the absolute temperature.

The relation to viscosity is with the magnetic permeability, which is denoted by μ, as is viscosity:

https://en.wikipedia.org/wiki/Permea...ctromagnetism)


https://en.wikipedia.org/wiki/Viscosity

Use of the Greek letter mu (μ) for the viscosity is common among mechanical and chemical engineers, as well as physicists.

[Ernst]

Maxwell's work is a little bit difficult to read and immediately understand. In his first treatise on the subject, he uses quaternions; a kind of imaginary vector calculus that is no longer taught at schools. Luckily in his later work (1864), he uses a more familiar notation and summarizes the main points of his earlier work into 20 equations. Using modern notation (vector calculus) 18 of these (1-dimensional) equations can be rewritten as 6 (3 dimensional) equations, thus giving us 8 equations.
This makes it all even easier to grasp, and from that moment things get fuzzy again (because people don't like the implications?)
So, start with those 8 equations and then work your way back to see where it came from.
Luckily, we are not the first ones with the desire to do this. In 2011 Frederick David Tombe wrote a paper that does exactly that and if you use his paper as a reading guide through Maxwell's original work things will quickly fall in place. His paper, although I do not agree with all of his conclusions, has been an excellent help to me in my exploration of Maxwell's work.
(together with many, many video chats with Koen van Vlaenderen who has made Maxwell his life work)
So, why this intro?
ε-naught refers to electric permittivity. Agreed.
μ-naught refers to magnetic permeability. Agreed.
BUT...
ε-naught comes from Maxwell's elasticity and μ-naught comes from ether density (momentum/inertia).
I'll attach Frederick's paper but I think, knowing you as a collector of these things, you already have it. In that case it is for forum readers.
Perhaps people will also appreciate André Waser's paper that deals with the different notations Maxwell used and the modern notation.


Ernst.
Original Equations.pdf Maxwell equations notation.pdf

[Ernst]

Previous experiments with the saw-tooth wave form:
Bought an AM transmitter with a digital tuner, something like this. Today you can buy something simlar with a 20W RF-amplifier included.
I added two amplifiers to get the power up to 120W and fed that into a small Tesla coil, designed for about 1MHz.
I have a couple of these signal generators, they come in a large variety. I used one to generate the saw tooth and fed that signal to the audio input of the AM-transmitter.
Here is the set-up in action:
RF-Amp test.jpg
Result:
Although the coil worked fine, as you can see by the lit fluorescent tube, the AM-modulation disappeared in the amplifiers. I don't remember hearing the low frequency noise that it should have generated and the spark on top of the Tesla coil is only very small. Not at all a QCW effect.

Now that I have a good scope I could revisit this project but I have, I think, a better idea.
I think if someone would like to explore this, it would be best to just buy the module with the 20W amplifier included and connect that to the Tesla coil. It is a low power system but it may actually work.

Ernst.

PS. I can see the image in this post let me know if others can see it as well.

[lamare]

One of the things I would like to explore here with the help of anyone who is interested, is how to detect these longitudinal waves in the medium.
I have an idea that Tesla did this with a coherer and that that is actually how a coherer works. Today you can obtain very fine nickel powder, made in some chemical process, and I think with that one could make a new generation of coherers. I did some tests with filings from various metals and found that nickel works the best by far.
But so far I have used filings. Now I have this very fine nickel powder, so I will make and test a coherer with that.

Interesting stuff. It seems even today it is not well understood how coherers actually work:

https://en.wikipedia.org/wiki/Coherer

Coherence of particles by radio waves is an obscure phenomenon that is not well understood even today. Recent experiments with particle coherers seem to have confirmed the hypothesis that the particles cohere by a micro-weld phenomenon caused by radio frequency electricity flowing across the small contact area between particles.^[9][10] The underlying principle of so-called "imperfect contact" coherers is also not well understood, but may involve a kind of tunneling of charge carriers across an imperfect junction between conductors.

The big problem with building antenna's (or probes) for Tesla waves is that these waves have no current density and capacitive coupling is required. I've tried building an antenna with a coaxial impedance matching section and a trimmer capacitor to a 1/2 wave longitudinal wavelength whip designed for 1.3 GHz, which didn't work. I measured the emitted wavelength and that turned out to be the normal 23 cm. See attached pdf, which also contains some measurements of the reactance of a number of coils. At the points where you get a sudden drop in reactance from positive (inductive) to negative (capacitive) you have a high impedance and that's where the Tesla resonances are, which we normally don't use. The interesting thing about these areas where a coil has a negative reactance is that it behaves like a capacitor at those frequencies and it appears that is the key to solving the coupling problem.

For detection, a so-called Avramenko-plug is interesting. Dr. Stiffler used that in his experiments as well, using an LED for C1 and a short wire as antenna/probe:

Avramenko_plug.png

Instead of a short wire as Stiffler used, a capacitive probe can be expected to work better.

Eric Dollard used a beercan as probe in his experiments, but his meter requires grounding, while the AV plug does not:


Dollard_beer_can_field_meter.jpg


It seems a typical satfinder circuit can be modified to build a meter with an amplifier to make it more sensitive:

Satellite_Finder.gif

Power supply to such a meter comes from a sattelite receiver through L1. At that point, an 18V DC power supply can be connected, so you don't need a receiver for powering the meter. L1 can then go.

The input circuitry already contains an AV plug and so it seems this circuit can detect both an EM surface wave as well as a FTL Tesla surface wave, although it would probably not be a good idea to use coaxial connectors and/or coax cable feedlines when intending to detect Tesla waves.

The problem is that this circuit can detect the presence of an E-field, which is present in both types of waves. When really wanting to detect Tesla waves to a large degree only, one would need a resonant probe (antenna) which would thus have to be tuned for a certain frequency band.

[kyle_dellaquila]

A redrawn schematic of Tesla's rotating coherer used to detect lightning standing waves:
OsjTC6w.jpg
Iron and nickel filings (fig.A) being aligned by longitudinal waves (fig.B) to where electric current from a battery can flow (fig. C):
bLbmzww.jpg
It would be interesting to isolate and discern the difference between fig.B & fig.C.
I would imagine that a better conducting path is aided with the presence of voltage between the two terminals of the coherer.
I would also imagine that a conducting path will occur regardless of the presence of applied DC voltage at the terminals of the coherer.
How would one measure the resistance without the presence of voltage? How would one observe the particles? A microscope? (fig. D):
calAIXc.jpg
The presence of earth longitudinal standing waves would result in the filling & un-filling of the antenna capacity which would appear as micro currents across all the filings – resulting in some alignment of some sort. The presence of a battery voltage would further assist the alignment process.

How would a coherer be any different than a transistor in detecting standing waves in a similar arrangement?
For instance – Steve McGreevy's receiver? From my observation, the conducting path is through the body to the tip of the antenna (small capacity/reservoir). The antenna being nowhere near as long as the wave being received. For I hear unmodulated amplified waves in the audio spectrum through the ear piece.

-Kyle Dell'Aquila

[kyle_dellaquila]

The trailing edge wave form produces sword like spikes and the illumination of the bulb as shown in your photograph.
It would be useful to show the same exact camera angle & exposure of the wave inverted. What would the discharge look like? Would the bulb be lit any differently?
KGXvNe1.jpg
-Kyle Dell'Aquila

[lamare]

Found some literature on coherers. First, a short video with a demonstration:

Then, a blog post about possible connections with the E-cat:

https://stretchingtheboundaries.blog...atalyzers.html

The device described by Sanford is a radio signal detector used in the receivers of wireless telegraphy at the beginning of the twentieth century. The coherer was invented, around 1890, by Édouard Branly [5]. As described by Sanford, it consisted of a tube or capsule containing two electrodes spaced a small distance apart, with metal filings in the space between them. To have the Branly effect, it is necessary a thin resistive layer between the grains, to have an initial high resistance. The effect is not observed with noble metal grains, cleaned from any surface contaminant. The coherer works because the metal particles cling together, that is cohere after being subjected to the radio frequency electricity. This provokes a reduction in the coherer's electrical resistance, which is persistent after the radio signal.

This refers a/o to an old book, with an illustration:

https://archive.org/details/elements.../2up?q=coherer

Also, some references to scientific papers:

https://core.ac.uk/download/pdf/52331544.pdf

We report on observations of the electrical transport within a chain of metallic beads (slightlyoxidised) under an applied stress. A transition from an insulating to a conductive state is observed asthe applied current is increased. The voltage-current (U–I) characteristics are nonlinear and hysteretic,and saturate to a low voltage per contact (0.4 V). Our 1D experiment allows us to understand phenomena(such as the “Branly effect”) related to this conduction transition by focusing on the nature of the contactsinstead of the structure of the granular network. We show that this transition comes from an electro-thermalcoupling in the vicinity of the microcontacts between each bead – the current flowing through these contactpoints generates their local heating which leads to an increase of their contact areas, and thus enhancestheir conduction. This current-induced temperature rise (up to 1050oC) results in the microsoldering ofthe contact points (even for voltages as low as 0.4 V).

https://arxiv.org/ftp/cond-mat/papers/0703/0703495.pdf

Understanding the Branly effect.


At the end of the nineteenth century Édouard Branly discovered that the electrical resistance of a granular metallic conductor could drop by several orders of magnitude when excited by the electromagnetic field emitted by an electrical spark[1]. Despite the fact that this effect has been used to detect radio waves in the early times of wireless telegraphy and more recently studied in the field of granular materials, no satisfactory explanation of the physical origin of the effect has been given yet. In this contribution we propose to relate the Branly effect to the induced tunnelling effect first described by François Bardou and Dominique Boosé [2].

https://www.sarganserland-walensee.c...a_Castaing.pdf

We show how a simple laboratory experiment can illustrate certain electrical transport properties ofmetallic granular media. At a low critical external voltage, a transition from an insulating to aconductive state is observed. This transition comes from an electro-thermal coupling in the vicinityof the microcontacts between grains where microwelding occurs. Our apparatus allows us to obtainan implicit determination of the microcontact temperature, which is analogous to the use of aresistive thermometer. The experiment also helps us explain an old problem, Branly’s coherer effect,which was used as a radio wave detector for the first wireless radio transmission, and is based onthe sensitivity of the conductivity of metal filings to an electromagnetic wave.

https://scienceblog.com/31887/cold-f...branly-effect/

A few years before 1900, the scientist Branly has discovered a phenomenon that has been used sometimes in radio communications. This phenomenon is the change of electric conductivity of a metallic powder by an electric current or an electromagnetic wave. The effect is reversible: a shock on the tube containing the powder restores the initial conductivity.

During a long time, the explanation of this effect has been controversial. But recently some experiments give a complete explanation of the phenomenon (see E. Falcon, B. Castaing, Electrical conductivity in granular media and Branly’s coherer: a simple experiment, in American Journal of Physics, vol. 73, pp. 302-307, 2005).

The modern vision of this phenomenon is now:
– the pellicular layer of oxide on each grain of the metallic powder gives an high electric resistance to the material,
– the electric current flows through very small contacts between the grains,
– the high density of current on resistive oxide layer melts the material by Joule effect and creates tiny metallic gates,
– when the metallic gates are established, the resistance of the powder decreases considerably,
– the resistive initial state of the powder can be retrieved by a shock on the tube containing the powder: the shock breaks all the tiny metallic gates between the grains.

The Branly effect shows the possibility to concentrate easily the electric energy in a very small amount of matter.

https://ieeexplore.ieee.org/stamp/st...number=5277448

Several explanations have been sug-gested to explain the Branly effect [7],first at the microscopic scale: electro-static attraction of the grains, electricalbreakdown of the metallic oxide layers,the tunnel effect, and, finally, localwelding of the grains through electro-thermal coupling and melting of microcontacts between grain surfaces. Macro-scopic phenomena were also invoked,such as electrical percolation. New char-acterization methods, such as 1/f elec-trical noise evaluation or infraredobservation of conduction paths, wereused, suggesting new theories [7]. How-ever, difficulties due to the quantitative-ly weak reproducibility of thephenomenon together with the highnumber of influencing parameters suchas aging, temperature, and grain mate-rials and size explain why, at the end ofthe 20th century, the theory of theBranly effect was still to be established[14].