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Science

Static Electricity Defies Simple Explanation 86

Posted by Soulskill
from the mr.-wizard-lied-to-me dept.
sciencehabit writes: "If you've ever wiggled a balloon against your hair, you know that rubbing together two different materials can generate static electricity. But rubbing bits of the same material can create static, too. Now, researchers have shot down a decades-old idea of how that same-stuff static comes about (study). '[The researchers] mixed grains of insulating zirconium dioxide-silicate with diameters of 251 micrometers and 326 micrometers and dropped them through a horizontal electric field, which pushed positively charged particles one way and negatively charged particles the other. They tracked tens of thousands of particles—by dropping an $85,000 high-speed camera alongside them. Sure enough, the smaller ones tended to be charged negatively and the larger ones positively, each accumulating 2 million charges on average. Then the researchers probed whether those charges could come from electrons already trapped on the grains' surfaces. They gently heated fresh grains to liberate the trapped electrons and let them "relax" back into less energetic states. As an electron undergoes such a transition, it emits a photon. So by counting photons, the researchers could tally the trapped electrons. "It's pretty amazing to me that they count every electron on a particle," Shinbrot says. The tally showed that the beads start out with far too few trapped electrons to explain the static buildup, Jaeger says.'"
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Static Electricity Defies Simple Explanation

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  • by Crypto Gnome (651401) on Saturday May 17, 2014 @10:35PM (#47029649) Homepage Journal
    will spark a lively discussion!
    • will spark a lively discussion!

      It won't be lively, but rather static.

    • by Darinbob (1142669)

      But static electricity never changes!

      • "a photon is emitted," is the electron "less?"
        • given that a photon is energy and energy is mass then "yes"
          • Re: (Score:2, Informative)

            by Anonymous Coward

            No, a photon is emitted when an electron looses energy, moving from one excited state to a "lower" excited state, or dropping valence levels (remembering from high school level quantum mechanics, so probably not *exactly* correct)

            Energy->Energry, not Mass->Energy.

  • by Anonymous Coward on Saturday May 17, 2014 @10:36PM (#47029653)

    The extra charge is for the other two seats your mama needs on the plane.

  • by NoNonAlphaCharsHere (2201864) on Saturday May 17, 2014 @10:49PM (#47029685)
    Gaussian surfaces, surface charges and boundaries, electrokinetics...

    Tell me again your "simple explanation" of static electric charge.
  • by Goldsmith (561202) on Saturday May 17, 2014 @10:51PM (#47029689)

    This is a great study, really cool. The title is unfortunate (it's clickbait), saved only by the weak qualifier "simple".

    The science question here is what is the charge carrier when you rub two identical materials together, electrons or ions? This study does a great job of showing that it's not electrons. At the end of the paper, they point out that small amounts of water adsorbed on the surfaces of these oxides should create H+ and OH- ions in a density that does explain the static generation effect.

    This water layer ion creation effect is fairly well known in materials physics. Until now, I don't think it was well known that it played any role in static generation.

    • by fuzzyfuzzyfungus (1223518) on Saturday May 17, 2014 @10:57PM (#47029705) Journal
      How difficult would it be to re-run the same procedure with fully dehydrated particles? Is this a 'just bake them under a modest vacuum for a bit' situation, or are these values of 'small' and 'adsorbed' the sort of thing where getting the water out would be a moderately heroic endeavor?
      • by Baloroth (2370816) on Saturday May 17, 2014 @11:40PM (#47029817)

        How difficult would it be to re-run the same procedure with fully dehydrated particles? Is this a 'just bake them under a modest vacuum for a bit' situation, or are these values of 'small' and 'adsorbed' the sort of thing where getting the water out would be a moderately heroic endeavor?

        Difficult, you'd need to run the entire process under an ultra-high vacuum. For reference, you to get water monolayer formation times greater than a second, you'd need pressures of roughly less than 10^-7 torr, or 10^-10 atmospheres. For reference (if WolframAlpha is to believed), the ISS is exposed to a pressure of about 10^-11 atmospheres. Molecular/ion pumps can get that low a pressure, so it's not impossible, just difficult.

        • So I'll take it that it could be done, even with the apparatus one might have, not merely in principle; but that my intuitions drawn from macroscale dessication are basically 100% irrelevant to the scale of the problem here.
        • Maybe this whole experiment should have been run in a vacuum regardless. Couldn't a possible source of the electrons be the air, or particles in it?
          • by RockDoctor (15477)
            That then begs the question of how long it takes to desorb that water monolayer, and to sufficiently dehydrate the interior of the particles to stop the monolayer from re-forming.

            I guess you'd need to get your materials into the vacuum, then bake them to a quite high temperature (olivine from lavas at over 1000degC can easily contain thousands of parts per million of water - which considerably affects it's physical properties), stir them (to get the water out of the mass and the crucible and off into the v

        • by AK Marc (707885)
          Why do the experiment on Earth with troublesome gear, when you can do the experiment at the ISS (well, just outside it)?
    • Well, I think it's pretty well known that you're more likely to shock yourself from static electricity in low humidity conditions (I haven't RTFA so will have to see how this observation jibes with the study). I always assumed it was because when there is higher water density in the air that charges are more evenly distributed in a room while in lower humidity charged surfaces are more isolated and when you touch something you make a conduit and feel the shock.
    • by ygslash (893445) on Sunday May 18, 2014 @04:52AM (#47030473) Journal

      The title is unfortunate (it's clickbait)... At the end of the paper, they point out that small amounts of water adsorbed on the surfaces of these oxides should create H+ and OH- ions in a density that does explain the static generation effect.

      No, that's just one of two alternative hypotheses mentioned at the end of the article. The second is transfer of the zirconium itself between the particles. There could be other ideas. The point of this study is only to eliminate the widely assumed electron-transfer hypothesis, not to establish any alternative. So the title is quite accurate.

      • by Goldsmith (561202)

        No, that's NOT mentioned in the actual study, just in the press release. Not sure why they're speculating about that at all.

        • by ygslash (893445)
          The paper itself mentions only the ion hypothesis; the article linked by OP attributes the other hypothesis to "Keith Forward, a chemical engineer at California State Polytechnic University, Pomona". The point is that the study makes no claim about the validity of any hypothesis. It only rejects the previously widely accepted one. So the title of the article is quite fair; it's not "clickbait".
    • by dkf (304284)

      H+

      Ugh. Why do people talk about those when they don't really exist for real, at least in terms of meaningful chemistry? A real raw H+ would be just a proton, and those are really quite rare. What you actually get are hydroxonium ions (in simplest form, H3O+, though H5O2+ and higher forms also occur).

      Raw protons are a meaningful thing in high-energy physics, of course. They just never occur in any quantity in solutions...

    • by whit3 (318913)

      This water layer ion creation effect is fairly well known in materials physics. Until now, I don't think it was well known that it played any role in static generation.

      While it might not be well known, it IS the best
      theory I've seen for lightning (air currents and gravity sorting ice particles causing charge separation).

    • Electrokinetic scientists hate him! Find out how generates static charge on identical materials with this one simple trick!

  • by l0ungeb0y (442022) on Sunday May 18, 2014 @12:15AM (#47029895) Homepage Journal

    It must be a miracle! Just like Climate Change and Magnets!

  • My interpretation of this is that the original hypothesis missed an important... law of nature? Mathematical necessity? Well, this:

    https://en.wikipedia.org/wiki/... [wikipedia.org]

  • You "record" a particle of energy (photon) doing something, but it takes energy (photons) to do it. So, in observing the process, photons are emitted and lost per 2nd law thermo?
  • "It's pretty amazing to me that they count every electron on a particle," Shinbrot says. The tally showed that the beads start out with far too few trapped electrons to explain the static buildup,

    They probably did not count every electron, then.

    • by Anonymous Coward

      Right, because only the things within the grasp of limited imaginations are likely to exist.

      Little known item: Occam was a monk who came up with his logical razor in an effort to prove the existence of god. "Because God made it so" is always simpler and requires fewer steps than any other explanation.

      People have been mis-using and mis-understanding Occam since that Jodi Foster movie.

    • by Anonymous Coward

      They probably did count every electron, since we can measure electrons and that was the point of the peer-reviewed experiment. If you can explain how they didn't, your assertion might be interesting. Right now, it's simply -1 trolling (spreading misinformation for the purposes of argument).

      Roughly 70% of the energy in the universe exists in the nothing between matter and within matter itself (the phasing of quantum matter in a proton : https://www.youtube.com/watch?... [youtube.com]). It would be plausible that static el

  • by Anonymous Coward

    Most of the damn year I curse the static electricity, especially in the winter when unloading steel trolleys covered in plastic wrap.

    Some day I will get a time machine and go back in time to murder the parents and grandparents of the asshole who invented plastic wrap and leave a note that says "this is what happens when you invent plastic wrap". Then I come back to present day to see if anybody else has invented it. Rinse and repeat until the most baffling mystery of humanity is an enormous amount of strang

  • It's pretty obvious from the paper that this is just more pseudo scientific "Static!" scaremongering to get folks to buy those stupid ESD bracelets and "non edible" silica packets. Let me get this straight: Not only are my delicate circuits vulnerable to some "invisible force" that only "scientists" can see, but now you tell me this because they're covered in a thin layer of water?!

  • It's pretty amazing to me that they count every electron on a particle," Shinbrot says.

    Millikan did that in 1909. [wikipedia.org]
  • When you think of things that make static, cling wrap, the belt of a Van de Graaff generator both seem to violate the friction idea. We have contact and surface area.

    At a job, I pulled fiberglass parts from molds, a situation where you often have very little friction, but a whole lot of surface area, and dielectric materials like glass rods, polyester and epoxy resin. The parts wouldn't come out of the waxed and PVA'ed molds if there was a lot of friction.

    When I pulled the parts from the molds, I converted

    • by Sanians (2738917)

      The problem is: if an electrostatic potential existed in the parts to begin with, separating the plates should diminish it, because if you squish a capacitor the charge is supposed to increase. So, in inverse must be true, right?

      A capacitor with plates closer together has a higher capacitance. This means that a voltage applied to that capacitor will cause more charge (a.k.a. electrons) to move between the plates, or in other words, it means that less voltage is required to cause the same amount of charge to move between the plates. So if you have two capacitors with identical charge, the one with plates closer together has a lower voltage, and the one with plates further apart has higher voltage.

      So whatever charge is on two surfa

  • by EmperorOfCanada (1332175) on Sunday May 18, 2014 @09:20AM (#47031311)
    I love when modest science take the air out of pompous science; I say this in that so many scientists act like they have all the answers; (I'm looking at you climate science.) When there are some first order bits of science that people don't understand: Things like why water freezes at the temperature it does, or what makes up the majority of the universe, and now static electricity.

    I am not saying that they are a bunch of halfwits, not at all, just that I respect the scientists who are clear on the idea that there is so much that we don't know. I don't respect the scientists who ever even hint that we are "reaching the end of science".

    If I were to have become a Physicist (my unrequited dream) this is all I would study, the little mysteries. I suspect that it would be harder to get a grant for static electricity than for something involving military devices, but based upon previous history, a discovery this fundamental would probably have huge technological repercussions. I have long thought that some of the biggest experiments such as the monster Fusion reactor in Europe (ITER) would find that money so much better spent on a zillion little plasma experiments. I think the budget blew well past $20 billion. I am 100% sure that if you gave 4000 of the world's top physicists $500,000 per year for the next decade that they would make leaps that would then make a fusion reactor a snap. My worry is that as they get the ITER turned on that they will find that they are having to wrap it in more and more duck tape to solve one problem after another. If this starts to happen during an economic crisis then the project will be shut down and all that time and effort will have been wasted. But think of the pomopsity of the scientists who are running that project. They will be able to preen themselves and go to all the best conferences where officials will swoon over them hoping to get a tiny piece of the budgetary pie. But they will go an entire career without ever turning the machine on so it doesn't matter if it works or not for them. A functioning machine would be a bonus. A functioning budget is all they care about; oh and good PR.

    Again I am willing to bet that more good science could end up coming out of these grains of sand than the whole of ITER.
    • I don't respect the scientists who ever even hint that we are "reaching the end of science".

      These scientists obviously don't want your respect, because they've been very naughty. Just push them down with your leathered heal and tell them they are bad boys. Also, we want their names in case any of them are not from Harvard, which is the only place you can get a "know-it-all" permit.

    • I love when modest science take the air out of pompous science; I say this in that so many scientists act like they have all the answers; (I'm looking at you climate science.)

      Yep. Climate science: where the problem is not so much scientists who think "they have all the answers", but scientists who have answers that you personally find distasteful.

      When a million results agree with one another, but are contradicted by a hundred results, the proper response is to figure out what's causing the contradiction, not to throw away the million results. Or the hundred.

      • Actually I wasn't thinking about the global warming debate but the predicting if this coming winter will even be cold or hot. Wet or dry. They blah blah about chaos theory but the reality is that things like La Nina and El Nino even seem to baffle them. These are monster movements of water.
      • by Trogre (513942)

        That's not how I read the GP at all.

        While the current trends are undeniable and a strong case for human causation exists, climate scientists, or at least people dressing up as climate scientists, often make statements beyond their expertise.

        I'm talking about bold predictions such as by year 20xx sea levels will rise by x mm or the polar ice caps will be xx% smaller or Chicago will be xx degrees hotter in winter.

        That's what I thought the GP was getting at, but I could of course be mistaken.

    • I love the igNobels. There are so often such obvious things that people take for granted, then someone decides to do a rigorous scientific study on it. A lot of people find them funny, and a good few of them are, but like "The Origin of Static Electricity" so many are little fundamental things that were important to _someone_ and they went about scientifically proving or disproving them.

  • Who paid for this study! Electric charges are extremely well understood, have been for nearly a hundred years! Charge builds, electrons jump energy bands and recombine with the holes in the electron cloud thus emitting photons. Simple. The researchers didn't measure the feild strength properly, nothing to see here keep moving.

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