Water has properties that are positively electrifying!

ResearchBlogging.orgMost people certainly understand how important water is for our survival, but we often overlook how weird it can be.  I can compile a short, though not exhaustive, list off the top of my head:

  • Water is less dense in solid form (ice) than in liquid form.  Ice cubes float, and ice forms at the top of lakes, protecting the fish and other organisms below from the cold.  Water is one of only a handful of substances for which this is true.
  • Water can be supercooled, and “instantly” frozen.  Very pure water can have its temperature lowered below the freezing point — supercooled — while remaining a liquid.  Any significant disruption of the liquid, such as pouring, will make it freeze almost instantaneously, as the video at this link shows.
  • In the right circumstances, hot water can be frozen faster than cold water! In 1963, a Tanzanian secondary school student named Erasto Mpemba noticed that hot ice cream mix froze faster than cold ice cream mix.  He pointed this out to a visiting physics lecturer, and the two published their experimental observations in 1969.  The effect is now known as the “Mpemba effect“.

Equally odd, but even less known, is the curious ability to bend a stream of water with static electricity.  I did this experiment at home a couple of weeks ago, and a snapshot of the result is below:

The rod is made of glass, and is what is generally known as a friction rod. The rod begins electrically neutral, but is stripped of electrons when rubbed with a piece of silk, leaving a net positive charge behind.  It is this positive electrical charge that attracts the water.

Why is water so strongly attracted to static electricity?  It turns out that the answer is somewhat complicated, and the complete explanation was a bit of a minor mystery for nearly eighty years!

To begin our explanation, we need to look at the molecular structure of water.  Its chemical formula is familiar to most people: H2O, which indicates that a single molecule of water consists of 2 hydrogen atoms (H) and one oxygen atom (O).  These atoms are held together by interactions of the electric charges of the atoms: their positive nuclei and their negative electrons.  If we could take a snapshot of a molecule, we would find that the atoms arrange themselves in a somewhat asymmetric manner:

The hydrogen atoms form a 105° angle with respect to the center of the oxygen molecule.  Though the molecule is overall electrically neutral (the amount of positive charge is the same as the negative charge), the oxygen atom exerts a stronger pull on the electrons than the hydrogen atoms do, and the negative charge therefore tends to group around it.  This leaves the hydrogen atoms on average positively charged and the oxygen atom negatively charged, and the resulting structure is what is known as an electric dipole.  The term “dipole” = “two poles”, referring to the fact that the charge distribution consists effectively of two distinct separated charges of opposite sign.   It is often drawn in a simple “ball-and-stick” form, as shown below:

Because a dipole has a spatial structure, it also has an orientation; the direction of a dipole is typically indicated by an arrow pointing from the negative charge to the positive charge.  A dipole produces an electric field, indicated by arrows in the following picture, which in turn creates a force on other charged particles:

It is natural to ask at this point: if water is a huge collection of electric dipoles, why isn’t water visibly electric under normal circumstances?  The answer is that ordinarily the dipoles are all in constant microscopic motion and any small volume contains a large number of randomly-oriented dipoles:

The effects of dipoles pointed in opposite directions cancel out; with a large number of dipoles in all directions, they produce no electrical effect.  This changes when a positive friction rod is brought near the water; then, the negative parts of the dipoles tend to be pulled towards the rod, and the positive parts repelled:

It should be noted that the alignment won’t be perfect: random motion of the molecules will prevent them from being perfectly aligned.  However, the stronger the applied electric field E, the more the dipoles will be forced into alignment.

The liquid in essence has a net negative charge on the side closest to the rod, and a net positive charge on the side farthest.  The dipoles near the rod are attracted to it, and in turn attract dipoles next to them, and so on, forming a “chain” of dipoles such that the entire body of water gets dragged towards the rod:

This basic description of the electrical properties of water is qualitatively accurate.  When researchers turned it into a quantitative model, however, they ran into a problem: water is much more electrically active than the model predicts!  Loosely speaking, researchers knew the electrical “strength” of an individual water molecule, and they knew how many molecules were in a given volume of water.  The whole body of water, however, was electrically stronger than the sum of the individual molecules: the whole is greater than the sum of the parts.

The answer turns out to be quite complicated, but involves an effect mostly absent from the simple model described above: interactions between the water molecules!  We have mentioned that, in a water molecule, the electrons tend to be drawn towards the oxygen atom.  This means that the oxygen atom is somewhat negatively charged and the hydrogen atoms are somewhat positively charged, and can attract one another.  This weak form of molecular bonding is referred to as a hydrogen bond.  The result of this bonding is that any given water molecule can be connected to up to four others in a tetrahedral shape, in which two hydrogen atoms can be stuck to a single oxygen atom (taken from Ref. [1]):

How does this affect the electrical properties of water?  Unlike our previous description of water molecules being randomly oriented, this tetrahedral arrangement means that nearby water molecules are oriented somewhat parallel.  This in turn means that, when an electric field is applied, groups of molecules can move together, providing an extra “oomph” to their electrical properties and presumably being more resistant to random molecular motion.  Furthermore, in liquid phase, these hydrogen bonds can be bent, allowing the dipoles to align even more parallel.

This alignment must be local, because without an external electrical influence, we expect water to be electrically neutral.  Our earlier picture can be crudely revised as shown below, in which molecules are locally parallel in small regions, but different regions have different orientations.  The net result is the same, in that every dipole has, on average, another nearby dipole that cancels it out!

With water molecules locally aligned, an additional effect is possible: the hydrogen bonds can then “stretch” the individual water molecules in a sort of “tug-of-war”!  This stretching can further separate the positive and negative charges of a water molecule, increasing its electrical strength.

These effects were already known as far back as the 1930s, but turning this qualitative understanding into an actual theoretical model that agreed with experiment turned out to be challenging.  Since 1933, a number of authors [2-4] developed increasingly accurate but more complicated models that came closer to experiment.  In 2007, a collaboration between workers in Princeton and Trieste [5] finally introduced a model that agreed well with the electrical properties of water at a range of temperatures, and could even account for the electrical properties of ice.

The strong electrical properties of water also account for its power as a solvent, able to dissolve a wide variety of other liquids and solids.  Of course, these strong electrical properties also account for the very dramatic “water-bending”, shown below in video!

It is somewhat eye-opening to realize that even a seemingly ordinary liquid such as water can hold many surprises for science, and very difficult challenges in understanding!

********************

1.  J.D. Bernal and R.H. Fowler, “A Theory of Water and Ionic Solution, with Particular Reference to Hydrogen and Hydroxyl Ions,” J. Chem. Phys. 1 (1933), 515.

2. L. Onsager, “Electric Moments of Molecules in Liquids,” J. Am. Chem. Soc. 58 (1936), 1486.

3. J.G. Kirkwood, “The Dielectric Polarization of Polar Liquids,” J. Chem. Phys. 7 (1939), 911.

4. J.A. Pople, “Molecular association in liquids. II. A theory of the structure of water,” Proc. Roy. Soc. Lond. A 205 (1951), 163.

5. Sharma M, Resta R, & Car R (2007). Dipolar correlations and the dielectric permittivity of water. Physical review letters, 98 (24) PMID: 17677991

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45 Responses to Water has properties that are positively electrifying!

  1. Blake Stacey says:

    Of course, these strong electrical properties also account for the very dramatic “water-bending”

    I see what you did there. Three elements to go! (-:

  2. daedalus2u says:

    I can’t see any of the images, but the bending of a water stream due to a static field is mostly due to charge separation not dielectric polarization.

    Water is conductive, water out of the tap is quite conductive (and is connected to ground). To maintain an electric field inside a stream of water requires a current to flow. To maintain dielectric polarization of water requires an electric field inside the water and so requires current flow inside the water to maintain the field. There is no source and sink of current in the water stream, the charged rod is a static field with essentially no charge flow (if there was charge flow the field would dissipate very rapidly).

    The field induces charge separation in the water (charge moves to the water surface closest to the charged rod) and then the field acts on the field (external to the water) produced by that charge separation.

    • J Thomas says:

      “The field induces charge separation in the water (charge moves to the water surface closest to the charged rod) and then the field acts on the field (external to the water) produced by that charge separation.”

      Interesting! So, as I understand it, Dr. Skulls says that it’s mostly the polarization acting locally. The polar molecules turn to increase the attraction, groups of them turn together to increase the attraction, etc. But you say that water is conductive enough that electrons leave their molecules and travel toward the positively charged glass, while the occasional positive hydrogen ion moves away from the glass. So there is an electric field which is large in size.

      Your idea has an intuitive appeal. After all, imagine a single row of polar molecules, all aligned.

      __ one molecule
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

      The difference between this and being aligned just as much the other direction is not very much.

      -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      A whole lot of alignment, and it’s like moving one single charge from one end to the other.

      But with your idea, it would be almost like the water would be acid on one side and base on the other. Lots of H+ ions one place and lots of OH- ions on the other.

      If that works, I wonder whether you could use it to do easier electrolysis. Use a strong electric field to separate the charges, and then a weaker electric current to generate H2 and O2.

    • Hmm… do you have a reference to your explanation? Pretty much every reference that I’ve found (e.g. Jefferson Lab) describes the water bending entirely due to the polar properties of water molecules.

  3. Scott Long says:

    Do you have an opinion on Gerald Pollack’s experiments which seem to indicate that water is more like a gel than a conventional liquid?

    Towards the end of the lecture he makes some (in my opinion) rather nutty claims, like how “ordered water” may be healthier than “unordered water,” but overall his “Cells, Gels and the Engines of Life” book, and the video, make some convincing arguments.

  4. Me says:

    Nice explanation Skulls. Wish i could read something like that everyday!

  5. Kees says:

    In the first image, you let the arrow point from – to +
    And also in the text:
    “Because a dipole has a spatial structure, it also has an orientation; the direction of a dipole is typically indicated by an arrow pointing from the negative charge to the positive charge.”

    In the second image, you let the arrows point from + to –

    Something is wrong here, right?

    • Ah, I can see how that would be confusing. The “direction” of a dipole is defined to point from the negative to the positive charge, as shown in the first picture. In the second picture, the arrows represent the electric field of the dipole, which points from the positive to the negative charge.

      The dipole “direction” is defined such that an electric dipole placed in an external electric field points in the direction of the external field. As I said, this is a definition for convenience, and could have been defined in exactly the opposite direction, although it would have been more confusing.

      • Kees says:

        Thanks, I will try to remember that. Hmmm, it seems more people make the same mistake: when I google: direction dipole, the fourth hit makes the same mistake as I did:

        http://answers.yahoo.com/question/index?qid=20081101101432AA5nUSb

      • One always ends up with a bit of confusion when it comes to definitions like this. It’s kind of similar to the choice of “positive” versus “negative” charge, which was somewhat arbitrary when Ben Franklin defined it but now means that current by definition flows in the opposite direction of the moving electrons in a wire!

  6. luise says:

    How is the person in the youtube video holding water cooled to -31 degrees with his bare hand? Am I missing something or is the video a fake?

    • I don’t think the video is a fake; there probably isn’t enough thermal contact between the man’s hand and the relatively non-heat-conducting plastic bottle to make it super uncomfortable.

  7. C V Horie says:

    Has anyone worked out the line of the water stream? i.e. the shape of the distortion, depending on the weight of the water, the force appiled by the rod etc. It should be possible to construct a mathematical model, but it is beyond me.

  8. The explanations is beautiful, but is wrong. Water is a conductor of electricity. Any charge near a conductor brings the free charge to the surface of the conductor until the internal field is zero. SO THERE IS NO FORCE ON THE WATER MOLECULES. the force is on the surface charges.
    From your model the water drops are uncharged, but the Kelvin Generator used them.

    • I’m not sure you can say that the explanation is wrong without some good references to back it up. Looking into the experimental studies on the effect, it looks like the best one can say is that there is still quite a bit of controversy about what contributes the most to the deflection force. For instance, there’s this paper that argues against a polar explanation:

      http://pubs.acs.org/doi/abs/10.1021/ed077p1520?journalCode=jceda8

      but there’s also this paper that argues for a polar explanation:

      http://pubs.acs.org/doi/abs/10.1021/ed073p887

      • Ii have published in The Physics Teacher 33 pag 420 an letter to the editor saying that. I have 30 years teaching electricity and the same time measuring the electric charge in water drops with an electrometer.ing with the dipole model there is no charge in a drop. Hewitt accepted my explanation. Any book says that the electric field inside a conductor is null. THERE IS NO FORCE ALIGNING THE WATER MOLECULES.There are too many wrong explanation in internet.

      • I’m certainly not opposed to the possibility, but your arguments are extremely unconvincing.

        with the dipole model there is no charge in a drop

        Is it an “either-or” situation? There’s no reason I can see why there can’t be dielectric and conductive properties together; you yourself say in your letter that “both mechanisms predict similar forces”.

        Any book says that the electric field inside a conductor is null.

        Actually, any book says that the electric field inside of a perfect conductor under static conditions is null. Ordinary drinking water is far, far from a perfect conductor: comparisons of the conductivity of a metal like silver versus drinking water shows nine orders of magnitude difference in conductivity. Considering also that we’re not in a static situation (falling water) and that the charge carriers in this case are heavy ions and not ultra-light electrons, I’m not sure that one can simply argue that the field is perfectly zero inside a water droplet and that the dielectric properties of water have no effect. I would think that people who have studied the dielectric properties of water for, oh, a century would have caught on to this.

        There seems to be precious little quantitative information about this effect that has been published; until I see strong evidence otherwise, I’ll stick with my explanation and the Jefferson Lab’s view.

      • The electrical conductivity has 25 orders of magnitud of difference between isolators and conductors. The electron response time is around 10exp-16 seconds. The ions time is around 10Exp-8 or -10 seconds. The flowing water has a very low speed.
        According with your explanations the net charge of a drop is null. The induced charge on the surface is of the other sign of the external charge. If the external charge is near the point where the drops form, then formed drops has a net charge given by the induce charge. If you collect the drops in an isolated cup, you can generate a high voltage. That is the principle of the Kelvin generator, known from many years ago.
        I believe that should convince you, even Hewitt accepted my explanation. Science is not democratic.

      • The electrical conductivity has 25 orders of magnitud of difference between isolators and conductors.

        Yes, and water falls pretty much smack-dab in the middle ground beneath isolators [sic] and conductors. One would think that this would give someone pause about treating water as a perfect conductor. There’s a reason why most E&M textbooks talk about water as a dielectric, and not as a conductor.

        According with your explanations the net charge of a drop is null.

        Did you even read my last comment? Is it an “either-or” situation? You’re basically making a straw man argument out of my discussion, by arguing that one must either have free charges or dipoles, and there’s no possibility of a middle ground. All evidence now suggests to me that there’s a combination of effects.

        I believe that should convince you, even Hewitt accepted my explanation. Science is not democratic.

        No, science is not democratic; it is built on consensus. And the consensus view seems to be against you, as most reputable sources talk about the dielectric properties of water and treat “water bending” as a dielectric effect. It is quite ironic that you say that science is not democratic, then argue that someone else “voted” in your favor. For the record, I’m not sure who “Hewitt” is, anyway, so it doesn’t help your argument, at least with me.

        If you’re absolutely convinced of your views, you should do some experiments, publish the results, and change peoples’ minds that way.

        I’ll leave these comments here for other folks who come by to consider for themselves. Further arguments with you in blog comments seem futile, and as far as I’m concerned the discussion ends here.

      • Paul Hewitt published the section Figuring Physics in The Physycs Teacher TPT from many years.
        He is the autor of Conceptual Physics, a text used in many countries with editions with more than 100 000 copies.
        He published the bending of a water stream by a charge explaining it by the dipole attraction. I send the letter with the correction to him and to the TPT. My letter was published TPT 33, 420
        Any conductor moves the internal free charges until the internal field is null, otherwise the internal charges keeps moving. The difference between conductors is the time needed to obtain the cancellation of the field. You need very high frecuencies to observe the dielectric character of water, to avoid the charge on the surface.
        The water dielectric constant is 78, the oil used in capacitors have around 7. Water is not used because conduces electricity and decomposes if the voltage produces electrolisis.

      • Nope. Not interested. Like I said, I’m done talking to you.

  9. Jimmydoneit! says:

    Hi Skillsinthestars.
    Love that your putting you’re mind to this. My cerebral circuitry was positively glowing after finding this blog! =)

    Question: Do you know if I can use a parallel bank of high voltage ultra/super capacitors and an electrode to achieve the same result as the glass rod?

    I have to say that this phenomenon is something that i’ve pondered since high school and filed away for later exploration. I also read a book recently that described generating sheet lightning from high velocity water through a nozzle. Supposedly the nozzle works like air currents in the clouds to create friction and thus sheet lightning in a special paraffin micro climate tube thingy. Would like to investigate when i have the time.

    Also have you heard of a self educated naturalist gentleman by the name of Viktor Schauberger?? (http://en.wikipedia.org/wiki/Viktor_Schauberger). He has some interesting views on properties of water and fluid dynamics. As he was self educated he was a little more open to the wacky energy movement. However that has given him some very authentic views that when given careful consideration don’t seem quite so wacky! Any way I’m an electrical engineering student and I want to investigate this water relationship with static electricity, to see if it can be used for wave power generation.

    Thank you for you’re inspirational blog.

    Jimmydoneit!

    • You should be able to bend water with any source of static electricity — just be very careful with high voltage, as water is conductive!

      I’m not familiar with Schauberger — I’ll have to look into him!

      • James Kay says:

        Schauberger, a staunch naturalist, was forced by the Nazis to participate in engineering anti-gravitic vehicles (including what was referred to as ‘the Glockenspiel’, or ‘Bell’ – source: Nick Cook, Jane’s Aerospace editor) some of which definitely resembled descriptions of UFOs, that were based on his discovery of how salmon actually utilized a vortex, created by the natural structuring of water based upon both temperature distribution and opposing magnetic field propagation, to ‘swim’ upstream…..Pollack, like Rostum Roy, the late Marcel Vogel and even Tesla himself, recognizes that ordering or structuring of water allows for much more efficient assimilation by cells…..

  10. Jimmydoneit! says:

    Fantastic! Great news i’m going to have some fun.

    I will use a current controlled power source and high frequency piezo amplifier with a full wave rectifier. So i’m thinking my little experiment will be shock survivable! so long as I insulate the plates and caps properly.. =) Plus I have some high frequency lads @ hacker space who are keen to play. Thanks again.

  11. Steve says:

    I see a lot of discussion regarding the ability to attract or bend water towards the rod, but I do not see any discussion regarding the ability to repel or bend the water away from a rod. Could that be done simply by reversing the “polarity”?

    • I’m actually not sure that one can do a water repulsion! If the water had an overall net charge to it, we could repel by bringing the opposite charge near it. However, the water is overall neutrally charged: if we bring a + charge near the stream, the – charges in the water get attracted, and vice versa.

    • If you applied a voltage source to the water container (a dropping can) then the drops get a net charge, Those can be repelled by an opposite charge

  12. steve says:

    really… I envision a cylinder formed like a pair of thruster nozzles top to top like this ” >< " attracting water at the front, charging in the middle and repelling it at the rear… hmmmmm worth playing with.

  13. Steve says:

    I would imagine that for this to work correctly I will need to avoid sinusoidal voltage specifically. I want specifically polarized currents. I am working out the design for the in/out nozzle now, then a little 3D printing and we’ll see what we can do… Anybody have suggestions for a tiny circuit to perform this separation of current? (Sorry, I’m just an overly enthusiastic ADHD craftsman with too much mind on my hands….)

  14. Mani Molian says:

    I guess we get cold/cough susceptibility due to the polar charges of water. Our external skin has
    a skin-battery potential. Consequently our skin is negative on outer side and positive inside. Any disruption in skin battery potential is conducted via the neuraxis of spine and spread to brain. When we are wet inside a pool or bathing, the positive polar hydrogen atom might change the natural negative charges of skin, disrupting the endogenous bio-electricity causing the cold, cough, infections etc. Our skin is more electronegative on hairy areas like scalp, etc. When our hair is wet we must dry up our hair as soon as possible to avoid reacting with polar charges of water. We should also avoid staying longer time in swim pools to minimize the electrical reaction.

  15. Checkout Stanley Meyer’s research and technology. Very interesting! https://www.youtube.com/watch?v=yGqCaVFWIWQ&list=UUQEihdXe89nsisHX8J-d81A

  16. Andrew Smith says:

    I have a question which I will post here since you all seem like smart people:

    If there is a flowing pipe of water, is the electrical resistance in both directions (with the flow, and against the flow) the same? Does velocity of charged ions have any effect on conductivity?

    Go ahead, make my day! 🙂

    • Hector G. Riveros says:

      The speed of the flowing wáter is very small compared with thar produced by the electric field.
      Also the direction of the velocity depends on the sign of the charge.
      The reistance is the same

    • James Kay says:

      …..if momentum of mass is obviously greater in one direction (due in part to fluid becoming structured by both the inner pipe surface and resultant field produced, as well any applied force) then the resistance HAS to be lower relative to velocity, as it’s a strictly rational value…..

  17. hamish says:

    i did this in class
    its weird but your right about
    (aparently)

  18. Michael says:

    I am tending towards macroscopic charge separation rather than polarisation in water. Charge separation in water is directly observed in the Kelvin water dropper and with water drops in electric fields. The charges are probably hydrated hydrogen ions and hydrated hydroxide ions.

    • KJ says:

      Is it possible to “infuse” both “love” and “moon” frequencies with water? There’s a company called findmyfrequency dotcom selling such wares so naturally I’m curious but not as knowledgable as you all seem to be. What do you think of such a product?

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