How does charge build up before sandstorm lightning ?

[William Gaatjes]

I had posted this video about lightning strikes.

http://www.youtube.com/watch?v=-bvmEYxEYiA&feature=player_embedded

In the thread in off topic we where wondering about how charges build up.
http://forums.anandtech.com/showthread.php?t=2095916


I thought, lets read for a second about lightning strikes in sandstorms and dust clouds above volcanoes. I found this article but i find it kind of strange that tjey do not give an explanation where the strange re-polarization comes from while having more charge as result.
Is that not strange to provide a model while not being able to explain why the model functions ?

http://www.technologyreview.com/blog/arxiv/24983/?ref=rss


Here is an excerpt, the article has pictures.

There are two parts to the problem. First, particles of sand are more or less identical, in size shape and chemistry. How then do they transfer charge between them? Second, sand particles are insulators, not conductors, which makes it doubly strange that they can be involved in the transfer of such massive amounts of charge. What on Earth is going on?

Today, Thomas Pähtz at the Swiss Federal Institute of Technology in Zurich and a couple of buddies say they can explain the whole thing with a deceptively simple new model. What's more, their model makes some straightforward predictions about the way sand particles transfer charge.

Here's their idea. They begin by thinking of sand particles as identical dielectric spheres. In an electric field, dielectric particles become polarised, causing charge to gather on each side of the sand spheres. When two spheres touch, the charge redistributes across the boundary between them, creating a larger, doubly polarised particle. The key idea is what happens when this breaks into two again: each particle ends up with a net charge (see picture above). The process of polarisation then begins again allowing the particles to increase their charge even further with each collision. It's not hard to see how a relatively small number of collisions could end up transferring huge amounts of charge in this way despite the absence of any kind of conducting medium.

From nature :

http://www.nature.com/nphys/journal/v6/n5/full/nphys1631.html

Grains in desert sandstorms spontaneously generate strong electrical charges; likewise volcanic dust plumes produce spectacular lightning displays. Charged particle clouds also cause devastating explosions in food, drug and coal processing industries. Despite the wide-ranging importance of granular charging in both nature and industry, even the simplest aspects of its causes remain elusive, because it is difficult to understand how inert grains in contact with little more than other inert grains can generate the large charges observed. Here, we present a simple yet predictive explanation for the charging of granular materials in collisional flows. We argue from very basic considerations that charge transfer can be expected in collisions of identical dielectric grains in the presence of an electric field, and we confirm the model’s predictions using discrete-element simulations and a tabletop granular experiment.

 

[Biftheunderstudy]

While it is strange that they did not describe what the repolarization actually is, did you read the actual paper and not just the blog?

That said, you can think about whats going on for a second and figure out how it works. The key thing here is that both the particles are in an external E field. When they collide they transfer charge, then they move away and the particle has to re-polarize in accordance to its new amount of charge and the existing field.

Quite clever really, and it seems to match the data too. Its a little unsettling that they don't know where the electric field comes from in the first place, but not unheard of.

 

[William Gaatjes]

While it is strange that they did not describe what the repolarization actually is, did you read the actual paper and not just the blog?

That said, you can think about whats going on for a second and figure out how it works. The key thing here is that both the particles are in an external E field. When they collide they transfer charge, then they move away and the particle has to re-polarize in accordance to its new amount of charge and the existing field.

Quite clever really, and it seems to match the data too. Its a little unsettling that they don't know where the electric field comes from in the first place, but not unheard of.

Well, i do not have permission or entrance for the paper.
I do understand what they mean. And yes, what you describe, i was aware of that. But i too was a little unsettled about them not explaining the origin of the electric field. Because i too was interested in the origin of the E field and the characteristics of the E field.

 

[Biftheunderstudy]

You can click on the link in the blog which will take you to the journal page and you can click the PDF only button on the top right which will take you to the paper. No special access required.

 

[William Gaatjes]

You can click on the link in the blog which will take you to the journal page and you can click the PDF only button on the top right which will take you to the paper. No special access required.

Really ?

Thank you indeed.

I guess i have undergone some Pavlov conditioning where every time i click on a link for a scientific paper, i do not have access. As such i started to make presumptions that links to scientific papers do not work and i no longer bother clicking the links. Time for a calibration update to remove this conditioning... : ^_^

 

[DominionSeraph]

Goddamn William is a pseudoscience magnet.

Here's their idea. They begin by thinking of sand particles as identical dielectric spheres. In an electric field, dielectric particles become polarised, causing charge to gather on each side of the sand spheres. When two spheres touch, the charge redistributes across the boundary between them, creating a larger, doubly polarised particle. The key idea is what happens when this breaks into two again: each particle ends up with a net charge (see picture above). The process of polarisation then begins again allowing the particles to increase their charge even further with each collision. It's not hard to see how a relatively small number of collisions could end up transferring huge amounts of charge in this way despite the absence of any kind of conducting medium.

The problem here is that the action of the assumed charge is in the direction of negation. It's not building charge.

Take a fully charged car battery. Short the leads. You are now moving electrons to the positive side and holes to the negative. Does this charge the battery?
No, you're draining the battery. You're not "increasing the negative voltage", you're draining the positive that you've started with. You don't end up with anything at -12VDC, you end at zero.

Same goes here. You can't assume +10,000,000 volts, have this "charge" the sand by -10,000,000 volts, and have that -10,000,000 volts discharge. Because you don't have -10,000,000 volts. You have zero volts.

Second, sand particles are insulators, not conductors, which makes it doubly strange that they can be involved in the transfer of such massive amounts of charge.

Wow, static electricity fail!

 

[William Gaatjes]

Goddamn William is a pseudoscience magnet.



The problem here is that the action of the assumed charge is in the direction of negation. It's not building charge.

Take a fully charged car battery. Short the leads. You are now moving electrons to the positive side and holes to the negative. Does this charge the battery?
No, you're draining the battery. You're not "increasing the negative voltage", you're draining the positive that you've started with. You don't end up with anything at -12VDC, you end at zero.

Same goes here. You can't assume +10,000,000 volts, have this "charge" the sand by -10,000,000 volts, and have that -10,000,000 volts discharge. Because you don't have -10,000,000 volts. You have zero volts.



Wow, static electricity fail!

Crackpot, stop using self confidence amplifying chemicals.

 

[Biftheunderstudy]

If I'm not mistaken, this same principle is how Van de Graff generators work. Polarising a dielectric and then stripping electrons off of it so that it acquires a net charge.

Read up on electrostatic induction and then return.

Nowhere does it say that it starts with a net charge, or that it makes the dust cloud not electrically neutral. The external electric field causes the charge separation and the collisions seem to enhance this process.

As for the pseudoscience comment, maybe william does have a penchant for pseudoscience but I don't think that this paper falls under that category. Its been published in Phys. Rev, though it is in biomed engineering....

 

[DominionSeraph]

As for the pseudoscience comment, maybe william does have a penchant for pseudoscience but I don't think that this paper falls under that category. Its been published in Phys. Rev, though it is in biomed engineering....

I didn't bother to check whether William had attracted pseudoscience or had created it himself. Looks like I got the source wrong.

 

[William Gaatjes]

I didn't bother to check whether William had attracted pseudoscience or had created it himself. Looks like I got the source wrong.

You are pathetic are you. Instead of blaming it on yourself you blame me ?

If you have the opinion that all i do is make up stories, then do not bother to respond. Many times me myself and others have told you you where wrong. Because you do not read or research, you directly assume you are right based on your lack of knowledge and your delusion of being superior to others. Therefore, i have grown accustomed to the rather disappointing notion that you are a troll. You will not accomplish anything with your attitude. Please stop using prozac.


To feed you a little more ^_^ :
Besides, my [gravity reaction to acceleration-stretched wavelengths-space time aether] idea supports the following subjects

* Hawkings radiation.
* evaporation of black holes.
* Accelerated expansion of space where the mass is more concentrated.
* Gravitational reshift.
* the modification of the trajectory of a free electron by gravity.
* the modification of the trajectory of an electron around a nucleus by gravity.
* Black holes.
* Missing matter also known as dark matter.
* Missing energy, also known as dark energy.
* The combined cold & heat death of the universe. ( One does not exclude the other)
* galaxy formation.
* Star formation.
* The de-unification of inherently different forces. A big error this unification is.
* dual particle wave nature. (There really are only 3d spherical waves.) The measured and calculated point particle is the perceived centre of mass of this 3d spherical wave. (The centre of mass is afcourse not really weight, but something else)
* The formation of the universe.
* elemental behaviour of "particles".
* intrinsic behaviour of elements.
* Fractal algorithms in self assembling nature.
* How life evolves based on the intrinsic properties of elements.
* The removal of time in any formula where the behaviour of "particles" is concerned.
* Only position is important. In a universe where the position is not a constant anyway, time cannot be a constant.
* Combinatory wave nature of electrons, simulating different properties of elements with other elements.
* And a lot more to come.


And i just do that by reading, a little bit of experimenting and combining what others way smarter then me discovered but who where and/or are in different fields. And my goal is that when people who are actually in these fields, start to think about, doing the research and find out what was overlooked. You see, i do not say or write that science is wrong. As a matter of fact it is rather obvious that since science could develop, suffering has decreased when in hands of those capable of using the through science discovered technologies wise. What i do say and write is that sometimes crucial aspects are overlooked or ignored by individuals seeking fame and fortune instead of seeking understanding. Every time this occurs, a temporary setback will occur. A delay in the progression of humanity.


The best part is, i do it for fun. I do not have to prove anything to any one. I will or do not want to get rich of it or recognized. But that is not what i am interested in anyway. Trivial desires i do not posses. It is the end result what is important. Finger pointing is useless, solving the problem while keeping moral limits is what is important.

EDIT:

Forgot to mention that i as anybody can make mistakes to. And as such there will be errors. There always are errors to be made. But that is where redundancy comes in. Accept that anyone can make errors but is willing to correct those errors. The same mechanisms that is responsible for creativity allow for errors to be made.

 

[William Gaatjes]

When reading my own post :
I do "sound" a bit like a mad scientist from the books and movies .



http://www.youtube.com/watch?v=7edeOEuXdMU


:biggrin::biggrin::biggrin:

 

[DominionSeraph]

Many times me myself and others have told you you where wrong.

Unlike you, I am not trying to rewrite physics. I can be wrong in an explanation without major effect because I do not claim to be the source of this knowledge. I am just a medium. The system has many pathways -- if mine is bad, another can step right in and take my place. I do not undermine this system of bypasses.

You, however, are claiming to be a source. But you show no restraint in what you believe. You make no attempt whatsoever to rip apart the things your brain happens to link together.

A source that will believe any falsehood is not exactly a good source.

What you have is a religion. Your religion of, "What William Gaatjes' brain happens to have farted out this time," does not supplant the scientific consensus. It isn't even in the same league as what scientists do. Yet you seek to undermine the credibility that their rigorous use of the scientific method grants them so that you can supplant their conclusions with your own and add members to your cult. Because your conclusions are aesthetically similar to those of real science there's a very real and continuing danger that others will conflate them for those of real science and in doing so mistakenly grant them the same level of credibility that science has earned.

I have a bit of a problem with this.

If you'd fix this and rein in your beliefs, I would no longer have a problem.
If you'd preface every post with a disclaimer along the lines of: "I don't check what I say against reality, so take anything that follows with a HUGE grain of salt," then I also wouldn't have a problem.

You might want to consider implementing one of those, because people don't like to be deceived.

 

[William Gaatjes]

Unlike you, I am not trying to rewrite physics. I can be wrong in an explanation without major effect because I do not claim to be the source of this knowledge. I am just a medium. The system has many pathways -- if mine is bad, another can step right in and take my place. I do not undermine this system of bypasses.

You, however, are claiming to be a source. But you show no restraint in what you believe. You make no attempt whatsoever to rip apart the things your brain happens to link together.

A source that will believe any falsehood is not exactly a good source.

What you have is a religion. Your religion of, "What William Gaatjes' brain happens to have farted out this time," does not supplant the scientific consensus. It isn't even in the same league as what scientists do. Yet you seek to undermine the credibility that their rigorous use of the scientific method grants them so that you can supplant their conclusions with your own and add members to your cult. Because your conclusions are aesthetically similar to those of real science there's a very real and continuing danger that others will conflate them for those of real science and in doing so mistakenly grant them the same level of credibility that science has earned.

I have a bit of a problem with this.

If you'd fix this and rein in your beliefs, I would no longer have a problem.
If you'd preface every post with a disclaimer along the lines of: "I don't check what I say against reality, so take anything that follows with a HUGE grain of salt," then I also wouldn't have a problem.

You might want to consider implementing one of those, because people don't like to be deceived.

You bore me. :thumbsdown:

Many times i have stated that it is my opinion and idea, even presented disclaimers. That i am not presenting the ultimate knowledge, just another way of looking at all what surrounds us and is part of us. Sometimes, i even asked with formula's to clarify what i have in mind. Yet nobody seems to be able to give me an explanation why i am wrong with mathematical and experimental proof. And that is because all is based on the same hypothesis
i use as well but with a different view based on the findings and mathemetics of others. And when i am wrong i am glad to admit it. Correcting my views in the process and usually solving what i could not solve. As for example with the electrons posts.

And you are a trolling complainer because all you do is nag about that my brain farts and that i am wrong, that i cannot and should not do anything.
When you can come up with a logical explanation i listen but all you do is call names and act surprised that i do not take you seriously. Which i really do not. The only reason why i still respond is because i do not wish to be a person who carries hate around for others.
I come up with idea's. Maybe wrong, maybe right. I do enjoy to discuss idea's. You seem only to enjoy to talk about others, clearly showing your lack of idea's and creativity. You remind of those gossip people as perez hilton. You could work for US weekly.


But since you as such seem to expect from me, i will behave as you seem to expect me too :

You dare to defy me ?
I want you to bow down for me, infidel !
Or i will unleash my vengeance upon you !
Accept me as your only god and master.
Sacrifice all what is dear to you at my command or i shall deem you not worthy !

Afcourse i pronounced all sentences at the same time with a slightly different
voice.

:biggrin::biggrin::biggrin:

Whats with you and brains anyway ?
Are you still looking for one ? :awe:

EDIT:
Forgot to mention one thing. If i am right or wrong or partially both, it is just the idea to make people think : "why" . In the end i really do not care if i am right or wrong. I bet on all horses instead of 1.

 

[Lemon law]

I wonder if there is another effect that this explanation may ignore, namely the peizo electric effect. Namely strike quartz crystals with physical blow and you get an electric charge out. And since most sand is merely eroded quartz from slowly cooling magma, and highly resistant to chemical degradation, quartz, unlike feldspar and other rocks never make it to the silt and clay phase of very tiny particle phase. And its partly why many desert soils are primarily sand, because the wind can carry off the smaller silt particles leaving the sand behind. And much the same can be said of beaches or similar water sorted deposits.

But some sands are non quartz based so it may be a testable hypothesis.

 

[William Gaatjes]

I wonder if there is another effect that this explanation may ignore, namely the peizo electric effect. Namely strike quartz crystals with physical blow and you get an electric charge out. And since most sand is merely eroded quartz from slowly cooling magma, and highly resistant to chemical degradation, quartz, unlike feldspar and other rocks never make it to the silt and clay phase of very tiny particle phase. And its partly why many desert soils are primarily sand, because the wind can carry off the smaller silt particles leaving the sand behind. And much the same can be said of beaches or similar water sorted deposits.

But some sands are non quartz based so it may be a testable hypothesis.

Indeed very interesting. I had not looked from that perspective. Thank you.
Worth thinking about it.

Piezo electric. ^_^

 

[William Gaatjes]

Hey Lemon Law,

I did some reading and an experiment was done at the humboldt university at Berlin. It seems shortly after formation of ice crystals with the use of distilled water in a temperature of around -2,5 degrees celcius also exhibit piezo electric behaviour . But this behaviour is erratic and depending on the time since the formation, thickness. It seems a lot of variables need to be met before something can be measured.

After storing the ice for 3 days at minus 20 degrees celcius , the effect was totally gone

Perhaps there is an interesting effect to be found here that can be used.
If it can ever be figured out how the charge separation amoung a cloud works and how the insulating molecules keep their strength. It might become useful one day. If i am not mistaking undercooled water droplets( still liquid below 0 degrees celcius) seem to form and hail is also not uncommon. Perhaps that is the reason...^_^


http://books.google.nl/books?id=zeX...ook_result&ct=result&resnum=8&ved=0CBkQ6AEwBw

 

[ModestGamer]

lots of silicon in sand. sand resides inside of the earths magnetic field. rotate a conductor in a field and you can create charge via particle motion. giant generator. you might think that wouldn't seem feasable but when you see the size of these storms it becomes obvious that A we have alot of sand particles in motion and B they are moving over a large area.

this is really not that complicated.

 

[Biftheunderstudy]

Sand isn't a conductor -- quite the opposite.