The Electric Comet theory

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A collection of problems with the EC idea

This will be updated as we discuss the many problems with the EC idea.

EC universe: Ignore the physical evidence such as the measured density of comets.
Real universe: Use the physical evidence such as the measured density of comets to construct theories.

EC universe: Comets are rocks.
Real universe:
  1. Comets have meaured densities that are much less than that of rocks (asteroids).
  2. Comets may not have the composition of asteriods
  3. Deep Impact confirmed that comet nuclei are made of dust and ice not rock. There were a couple of surprises in that the dust was talcum powder rather than sand and the amount of ice was smaller than expected.
    "Analysis of data from the Swift X-ray telescope showed that the comet continued outgassing from the impact for 13 days, with a peak five days after impact. A total of 5 million kilograms (11 million pounds) of water[35] and between 10 and 25 million kilograms (22 and 55 million pounds) of dust were lost from the impact."WP
EC universe: Comet jets, coma and tails are created from material that that is created from rock by electrical discharge machining.
Real universe:
Start with Tim Thompson's posts about this
Then look at
EC universe: Rocky bodies that have an orbit with an eccentricity above a minimum value will be comets.N.B. Solar activity may cut tails in two but there have been no observations of comets turning off during low solar activity.(Sol88: I may be wrong - if so please provide the citations to these marvelous events.)
However this assertion has the fatal flaw of EC predictions - no mathematics or numbers.
But we can do their work for them can't we Sol88?

There are 4 observed main-belt comets with a minimum eccentricity of 0.1644 (133P/Elst-Pizarro). So the EC minimim must be this (or lower!).

Real universe: There are at least 173,583 asteroids (rocky bodies) that have an orbit with an eccentricity above a minimum value that are not comets. This includes asteroids that have been observed for decades.
Why EC comets are not asteriods


EC universe: Only give qualitative predictions.
Sol88 posted a list of EC "predictions" for Tempel 1 and Deep Impact. The closes it gets to an actual quantitative predictions is "The most obvious would be a flash (lightning-like discharge) shortly before impact." (emphasis added).

What actually happened was a flash on or after impact followed by a bigger one from deeper in the nucleus (according to NASA).

Real universe: Scientific theories model the data mathematically and produce both qualitative and quantitative predictions.
Someone could start with the papers of Whipple
  1. Whipple, Fred L. (1950). "A Comet Model. I. The acceleration of Comet Encke". Astrophys. J. 111: 375–394.
  2. Whipple, Fred L. (1951). "A Comet Model. II. Physical Relations for Comets and Meteors". Astrophys. J. 113: 464.
  3. Whipple, Fred L. (1955). "A Comet Model. III. The Zodiacal Light". Astrophys. J. 121: 750.
and then go ointo the 1000's of scientific papers and many textbooks about comets. Tim Thompson recommened Introduction to Comets by Brandt & Chapman (Cambridge University Press, 2004, 2nd edition).


EC universe: Turn yourself into a crackpot idea by not publishing papers in peer reviewed journals.
Real universe: Take the risk being wrong and become part of the scientific process by publishing papers in peer reviewed journals, e.g. Fred L. Whipple.
 
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Sol88 said:
That's splitt'n hairs in it?

Which tail would you like to talk about?
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Your being very silly.

try just explaing why the tail gets longer as it passes the sun. By then the charge difference should have balanced out. And why do the four cometary asteroid get a charge difference from the other asteroiads.

Your theory, your explanation.

They come from the outer solar system witha charge, that charge causes an interaction you say cause the coma and tail to develop. So why is it larger after they pass the sun?
 
Hi all. First post here. What fun, mind if I jump in? :)
First...EDM. EDM is the erosion or etching of an electrode. It could be a rapid, dramatic process, or a slow, steady process. Spark machining is used on very hard materials in industrial manufacturing processes. The slow erosion of the electrodes in a neon sign is a slower, less obvious form of EDM. We could say coronal discharge etching, but the electro-static potential may, at times, reach the threshold for arcing. We say EDM because there are multiple discharge levels occurring on comets, from electrostatic cleaning of dust, coronal discharge erosion, "magnetic vortex" etching, and possibly, infrequent arc machining.
The voltage potential between the comet and the solar wind plasma (concentrated at the plasma double layer which makes the boundary of the coma, where the x-ray's are produced, in the DL) induces electro-chemical reaction chains on the nucleus, which together form a positive feedback, increasing the efficiency of each. The chemical reactions are similar to an acid H+ (solar wind plasma ions) and base/alkali (mineral rock, i.e. comet) reaction. The by products would include hydrogen, oxygen and carbon groups in abundance, and to a lesser extent, sodium, nitrogen and sulfur groups. H2O is a common by-product of an acid base reaction, this would be the source of the .026% surface area of 3 thin ice layers detected on Tempel-1, probably deposited as the comet moved further away and the reactions subsided, because the final reaction in that chain produces OH. :D
 
OK. As for composition. Composition and structure are what's important, not density. As the stardust mission indicates, the material consisted of crystaline silicates, a variety of other minerals and metals. A very good semi-conductor. Density is irrelevant in EC, it's a red herring that Reality Check continues to go in circles over.
I am in no way an official spokesperson for EU or EC. However, until we actually land on a comet and poke at it, we don't really know the density. My personal prediction (NOT official EU/EC) is that it should be around 2.8g/cm3, +/- .2, based on the material collected from stardust and comparing to the density of quartz.
An EC rock has the same definition as any rock.
What makes a rock into a comet is sufficient electro-static voltage potential to induce an electro-chemical reaction/coronal discharge. That could be produced by an eccentric orbit, or a stream or bubble of solar wind plasma with a significantly different charge density, or composition, than the surrounding plasma.

sol88 has used some incorrect terminology. Allow me to clear up any confusion.
The EC comet is not a dielectric, it's a semi-conductor, capable of accumulating an electric charge. The solar wind plasma is an electrolyte, a conductive, chemically reactive material.
Otherwise, good job sol88!

I find it quite humorous and ironic that the MESSENGER probe to Mercury discovered chemical sputtering all over the surface, and "magnetic tornado's" ripping ions and neutrals from the surface, and detected a filamentary tail. Pretty much a "dark comet". ;) The chemical reaction off-gassing was even similar to that found from comets, including OH :p. But they can't connect the dots. :(
We should study the weaker processes on Mercury for an idea of what an energetic EC comet is about.
 
Welcome to JREF Forum, solrey. :)

One thing I found interesting is that there are no numbers in your posts!

For example, what potential differences and/or currents are needed to cause what amount of EDM? And are there any thresholds (e.g. below certain values, no EDM takes place, period)?

Further, what's the evidence for the existence of potential differences, and currents, in the parts of the interplanetary medium through which comets move? Specifically, what are the estimated max (and min) values of potential differences (between various pairs of objects, or locations) and currents?

Chemistry: what are the specific reactions, or classes of reactions, that you think could give rise to the observed levels of OH? AFAIK, the existing body of knowledge - experiments, theory - is more than adequate to provide a basis for testing specific hypotheses concerning OH production ...

Oh, and I am unaware of the MESSENGER results you mention; normally, I'd ask for some reference material, but you won't be able to provide any until your post count exceeds 15 (IIRC) ...
 
DeiRenDopa, thanks for the warm welcome. :)

Forgot to mention that even though the EC comet would be considered a semi-conductor, the material at the surface involved in the discharge does act as a dielectric, however. Essentially the semi-conductor discharges through dielectric layers. ;)

Good questions deirendopa. As I can't post links yet, may I suggest to copy/paste this into google search: Physics of arcing, and implications to sputter deposition Anders
You should find the second entry down to be the PDF you want.

I think there is a lot of what you're looking for in there. Here's a taste:

Arc and glow discharges are defined based on their cathode processes. Arcs are characterized by collective electron emission, which can be stationary with hot cathodes (thermionic arcs), or non- stationary with cold cathodes (cathodic arcs).
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In the case of the EC comet, we are dealing primarily with cathodic arcs.

Arcing on sputter targets and negatively biased substrates is known as one of the most challenging issues in physical vapor deposition of thin films and coatings. This is particularly true when high-rate deposition with reactive gases, large area deposition, and high power pulse sputtering are considered... However, relatively little is known about the processes leading to arcs and the physics of the arcing events themselves. In this contribution, the issue of arcing is approached from the point of view of arc physics.
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One may consider the operation of cathodic arc spots as a rapid sequence of microexplosions. In these explosive events, large amounts of electrons can overcome the potential barrier. The cathode material in the vicinity of the spot experiences phase transformations, ultimately resulting in fully ionized, rapidly expanding plasma. Thermal conduction in the solid increases the active spot area and reduces the power density, while the electrical conductivity below the spot is reduced at high temperature. Therefore, a microexplosion destroys its own favorable condition. As a side effect of plasma formation, material located between the dense plasma and the much colder cathode is in the liquid phase, subject to the pressure of the plasma. As a result, the material is ejected as droplets or “macroparticles,” often under shallow angle to the cathode surface, and a crater is left on the cathode surface. The formation of macroparticles is highly undesirable and a major reason why arcing is of great concern to sputter deposition.
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Magnetron discharges are magnetically enhanced glow discharges, where the ionization probability of gas atoms or molecules by electron impact is greatly enhanced due to the motion of electrons in the ExB field. Although the plasma density is higher, and the operational pressure may be lower than in glow discharges without magnetic field, the cathode processes are still indicative for the glow nature of the discharge. Secondary electron emission by primary ions is only efficient when the impact energy exceeds about a couple of 100 V, hence the glow discharge voltage is high, usually many 100 V. Besides providing energy for secondary electron emission, primary ions bring enough energy to overcome the surface binding energy of atoms, leading to target sputtering, the desirable side effect that made us work in this field in the first place.
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Think of the bright spots on the surface of the nucleus where the jets originate. Conventional thinking is reflected sunlight, EC thinking is more like magnetron glow discharge, the suns magnetic field providing the magnetic enhancement. ;)
 
Have you seen that image of the Martian dust devil with the electric glow discharge at and just above the surface? The jets of the EC comet as applied to the above referenced magnetron glow discharge are a lot like that. :)
Actually, that discharge at the base of the dust devil is a magnetron glow discharge. ;)
 
solrey said:
Have you seen that image of the Martian dust devil with the electric glow discharge at and just above the surface? The jets of the EC comet as applied to the above referenced magnetron glow discharge are a lot like that. :)
Actually, that discharge at the base of the dust devil is a magnetron glow discharge. ;)
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You can post links in a modified form like www_engrish_com
 
solrey said:
DeiRenDopa, thanks for the warm welcome. :)

Forgot to mention that even though the EC comet would be considered a semi-conductor, the material at the surface involved in the discharge does act as a dielectric, however. Essentially the semi-conductor discharges through dielectric layers. ;)

Good questions deirendopa. As I can't post links yet, may I suggest to copy/paste this into google search: Physics of arcing, and implications to sputter deposition Anders
You should find the second entry down to be the PDF you want.

I think there is a lot of what you're looking for in there. Here's a taste:



In the case of the EC comet, we are dealing primarily with cathodic arcs.







Think of the bright spots on the surface of the nucleus where the jets originate. Conventional thinking is reflected sunlight, EC thinking is more like magnetron glow discharge, the suns magnetic field providing the magnetic enhancement. ;)
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http://www.osti.gov/bridge/servlets/purl/861163-A0F82g/861163.PDF
 
Thanks solrey.

I'm curious about this: "Think of the bright spots on the surface of the nucleus where the jets originate. Conventional thinking is reflected sunlight, EC thinking is more like magnetron glow discharge, the suns magnetic field providing the magnetic enhancement."

From what I have read, doing a bit of googling, a magnetron requires a magnetic field strength of at least a few gauss, yet the magnetic field strength in the solar wind is ~a few nT ... so how could there be a magnetron glow discharge at such low magnetic fields?

Also, what image analyses have been done (if any), to show that the emission from "the bright spots" is greater than the incident sunlight?
 
In the context of the magnetron glow discharge, it simply designates the presence of an external magnetic field, it could be weak or strong or all points in between. They are not literally referring to the magnetron as a device nor inferring a B field of similar strength. Any strength B field will have some effect. It is simply a magnetically enhanced glow discharge. I believe the authors definition and equations will confirm this.

As far as emission of the bright jets goes, I should have been more specific and clear that at or near the surface is mostly due to the glow discharge, but at some point reflectivity of the dust and discharge blend with distance from the nucleus until eventually it's mostly a result of reflection. Both glow and reflection are happening, but at or near the surface, there is the enhancement of the glow discharge. It's not necessarily one or the other, I should have been clear on that. :o

That also is analogous to the ionization distribution of the reaction by-product gases. The closer to the nucleus the more ionization, the free electrons liberated by the discharge combine with ions as both travel away from the nucleus, so there should be an increasing proportion of neutral atoms and molecules with increasing distance from the nucleus. I believe the conventional explanation would involve ionization due to friction, or triboluminesence.

The coma boundary is a plasma double layer. One of the functions is diffusing the voltage potential across a greater surface area, which mitigates the discharge to the surface, while dissipating most of the energy in the form of x-rays at the boundary of the coma, or DL. It's a well known plasma phenomena, and a prime reason for Alfven's eventual Nobel prize. He even said that DL's should be treated as a specific cosmologic/astrophysical phenomena. The tail is just the DL being stretched by the solar plasma stream, basically stretching between a positive and negative potential, from bow shock (+) to end of tail (-). The tail contains the twisted filaments of the discharge current, Biot-Savart law and the Bennet relation are applicable here.

One more point. The material from stardust mission that was formed in high temps could have come from the material being in plasma state in those micro-explosions of the glow discharge, described in the paper, prior to rapid cooling and re-solidification. ;)

This seems like a friendly forum, good questions, agree to disagree, respectful, yeah respectful...how refreshing. :D

Whew, busy day. Sanding a porch deck for refinishing and posting during breaks. Luv it, a little physical and mental exercise.
The deep thoughts keep me from getting bored stiff while sanding. :p
 
solrey said:
In the context of the magnetron glow discharge, it simply designates the presence of an external magnetic field, it could be weak or strong or all points in between. They are not literally referring to the magnetron as a device nor inferring a B field of similar strength. Any strength B field will have some effect. It is simply a magnetically enhanced glow discharge. I believe the authors definition and equations will confirm this.
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(bold added)

Yes, that does make it a bit clearer.

However, surely the details matter a great deal, don't they?

I mean if at 10nT the magnetic field enhances a glow discharge by 0.1% (or less), the distinction between a magnetron glow discharge and an ordinary glow discharge is, observationally, irrelevant, isn't it?

I haven't gone through the material you cited in detail yet, but as I'm sure you have, can you please point out the expected extent by which a magnetic field of strength typically found in the solar wind would enhance a glow discharge?

As far as emission of the bright jets goes, I should have been more specific and clear that at or near the surface is mostly due to the glow discharge, but at some point reflectivity of the dust and discharge blend with distance from the nucleus until eventually it's mostly a result of reflection. Both glow and reflection are happening, but at or near the surface, there is the enhancement of the glow discharge. It's not necessarily one or the other, I should have been clear on that. :o
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Thanks for the clarification.

From image analysis, of images returned by the various spaceprobes which have resolved the points where the jets originate, what evidence is there that the detected emission exceeds that expected from reflected sunlight? I assume, given the detail you have been posting on EC, that such analyses have been done.

That also is analogous to the ionization distribution of the reaction by-product gases. The closer to the nucleus the more ionization, the free electrons liberated by the discharge combine with ions as both travel away from the nucleus, so there should be an increasing proportion of neutral atoms and molecules with increasing distance from the nucleus. I believe the conventional explanation would involve ionization due to friction, or triboluminesence.
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This is related to the reactions that might be taking place; perhaps we could look at this in more detail after your postcount has reached 16?

The coma boundary is a plasma double layer. One of the functions is diffusing the voltage potential across a greater surface area, which mitigates the discharge to the surface, while dissipating most of the energy in the form of x-rays at the boundary of the coma, or DL. It's a well known plasma phenomena, and a prime reason for Alfven's eventual Nobel prize. He even said that DL's should be treated as a specific cosmologic/astrophysical phenomena. The tail is just the DL being stretched by the solar plasma stream, basically stretching between a positive and negative potential, from bow shock (+) to end of tail (-). The tail contains the twisted filaments of the discharge current, Biot-Savart law and the Bennet relation are applicable here.
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There's a lot here, and I think it might be a good idea to look at it in a methodical fashion.

The aspect that I am most curious about, now, is why comets? I mean, why do comets have comas (and tails), but other solar system bodies do not?

Related to this: several spacecraft have travelled through comet comas, and they were equipped with functioning plasma physics instruments (IIRC). From the data returned from these instruments, what signature(s) of DLs are there (in these comet comas)?

One more point. The material from stardust mission that was formed in high temps could have come from the material being in plasma state in those micro-explosions of the glow discharge, described in the paper, prior to rapid cooling and re-solidification. ;)

This seems like a friendly forum, good questions, agree to disagree, respectful, yeah respectful...how refreshing. :D

Whew, busy day. Sanding a porch deck for refinishing and posting during breaks. Luv it, a little physical and mental exercise.
The deep thoughts keep me from getting bored stiff while sanding. :p
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Sounds like fun! :p
 
solrey said:
The voltage potential between the comet and the solar wind plasma (concentrated at the plasma double layer which makes the boundary of the coma, where the x-ray's are produced, in the DL) induces electro-chemical reaction chains on the nucleus, which together form a positive feedback, increasing the efficiency of each.
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Well, there is a lot of problems with this picture.
Take for example data that have been obtained at Comet Halley with the Vega flyby through the interesting regions of the coma, as reported by Harri Laakso.

Harri discerns three different regions:

Laakso said:
Based upon the behavior of the electric fields and the cold electrons, three regions can be identified in the cometosheath (in particular during the Vega 1 approach): transition layers are passed through at ∼780,000 km (R 1) and ∼360,000 km (R 2). The outer cometosheath (near and beyond R 1) is characterized by large-scale variations in the cold electron density and the electric field, peaking at ∼1 mHz. The R 2 crossing is detected in the plasma wave data as enhanced fluctuations at ∼15 mHz. About 25,000 km downstream of R 2, the spacecraft traverses a current layer (thickness ∼10,000 km) indicated by a sharp gradient in the dc electric field and the cold electron density.
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So, there is a DC electric field/current layer downstream of R2 with a thickness of ~10000 km. Now say that this would be the double layer (just for argument's sake, I am not saying it is really so) then the "bottom" of the DL would be at 360000 - 25000 - 10000 = 325000 km from the nucleus of the comet. That would be one humongous lightning flash or arc or whatever if the discharge would, for some reason which escapes me fully, go from the "electric field concentrated at the DL" and the nucleus of the comet.

For one, the problem is that if the electric field is indeed concentrated there, that means that any "discharges" would be inside the DL, there is no reason why there would be a discharge from the DL to the nucleus, as the inner side of the DL would have the same potential as the nucleus. Just like in a double plasma machine in which you generate a DL in the plasma column and one side has the potential of the anode and one side that of the cathode. (unfortunately I cannot find a figure of the potential in a double plasma machine at the moment).

Now, such discharges would emit radiation, specifically whistler mode waves. These are indeed observed, however Harri writes in the paper:

Laakso said:
The whistler emissions are excited by suprathermal electrons accelerated by lower hybrid waves, and therefore the intensity of whistler emission permits an assessment of the flux of suprathermal electrons [Galeev, 1987].
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There seems to be no indication that discharges happen, indeed they are not mentioned at all in the whole paper.

Then with respect to the X-rays, which supposedly are produced in the DL. It has been shown by Tim Thompson a few pages back that the X-rays are completely described by electron bremsstrahlung (for the continuum) and by nuclear excitation (for the line emissions). Just scroll a few pages back and you will find it.

Now, the question is, actually, what kind of double layer should be present in the coma of the comet? As you might or might not know, there are two different kinds of double layers, one carrying a current and one not carrying a current. You might think this is "nitpicking" but it has some very specific consequences for the physics.

So, it would be nice if an EC proponent would come with a real model.
 
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