Posted on 06/25/2011 1:04:02 AM PDT by neverdem
Charges build up due to exchange of material, study suggests
A balloon rubbed against the head can be both a hair-raising and a hair-tearing experience, a new study suggests. Clumps of balloon and hair invisible to the naked eye may break off each object during contact and stick to the other.
The existence of this exchange could challenge traditional theories about how static electricity builds up, a process known as contact electrification.
“The basic assumptions people have made about contact electrification are wrong,” says Bartosz Grzybowski, a physical chemist at Northwestern University in Evanston, Ill. He and his colleagues describe their new take on static electricity online June 23 in Science.
It’s long been known that some insulators — materials that don’t conduct electricity — build up charge when rubbed together. One object is usually assumed to pick up positive charges uniformly distributed across its surface, while the other picks up negative charges. Where these charges come from isn’t known for sure, though some experiments point to the movement of charged particles such as electrons or ions.
Working within this framework, many scientists have rubbed together different insulators and ranked them from those with the greatest tendency to turn positive, such as wool, to those that tend to go negative, such as Teflon. Materials farther apart on this “triboelectric series” are thought to be more able to charge each other, setting up the kind of situation that can end with a shock.
Last year, though, Grzybowski’s team showed that identical pieces of polymer can charge each other when touched. Now they’ve use a technique called Kelvin force microscopy to take a closer look at various polymers brought into contact. The surface of each object, they discovered, was not simply positive or negative — but coated by an intricate quilt of...
(Excerpt) Read more at sciencenews.org ...
Abstract
When dielectric materials are brought into contact and then separated, they develop static electricity. For centuries, it has been assumed that such contact charging derives from the spatially homogeneous material properties (along the material's surface) and that within a given pair of materials, one charges uniformly positively and the other negatively. We demonstrate that this picture of contact charging is incorrect. While each contact-electrified piece develops a net charge of either positive or negative polarity, each surface supports a random “mosaic” of oppositely charged regions of nanoscopic dimensions. These mosaics of surface charge have the same topological characteristics for different types of electrified dielectrics and accommodate significantly more charge per unit area than previously thought.So much for that "settled science" consensus. Hat tip to American Thinker's Thomas Lifson's blog entry.
Ay, there’s the rub in triboelectricity :-)
As anybody who has tried to unpeel a stubborn roll of Saran Wrap knows, or tried to get a cut and wrinkled piece of that wrap unstuck from itself, yes the same insulating dielectric can assume different polarities of charge when touching itself.
I wonder if the polarities obtained thereby are random or if there is some way to force what they will be.
It’s amazing how little we know about things that can be directly and repeatedly observed and how much we pretend to know about things that we will never observe even once.
So if they are truly identical, how do the pieces decide which is going to become positive or negative?
>>> Charges build up due to exchange of material...<<<
So this is where the ZOT comes from.
That is such a good point. Since it is apparent we haven’t got a clue scientifically about static electricity and have been absolutely wrong about it, to date, then what make us think we really understand fundamental physics pertaining to human beings, the universe, etc.
“.... then what make us think we really understand fundamental physics pertaining to human beings, the universe, etc.”
Your point is excellent. It would be a big surprise if a century or two from now we didn’t look back at much of what is currently ‘dogma’ and think, ‘wow, it’s amazing what people used to believe’. There is no room for arrogance.
Also, whose to say that what we hold as physical ‘Laws’ are ‘universal’. What if there are other areas of the universe, or other parallel universes where they aren’t valid? We don’t even know fundamental things like why particles of like charge repel each other, or why mass attracts mass. What exactly is the ‘force of gravity’?
Speaking on behalf of public education: As long as we don’t deny we evolved from apes we’re on solid ground.
bttt
The answer is right in front of us. All these things mentioned by you and others are due to electricity. Atoms, planets, clusters of galaxies.... all work on the same principle. It is what caused the bits and pieces of the early universe to 'clump' together. A scientist has already discovered this 'clumping' effect, which surprised everyone. He was just experimenting while on the Space Station, and wasn't trying to find this particular answer.
The movement of everything in the Universe alters the balance of the electrical charge of the material in the Universe, causing it to attract or repel other material. The electrical 'potential' is like water. It will seek the lowest point. Electricity seeks a perfect BALANCE (net charge of zero). Which we don't want, because if it happens, nothing will exist.
In that most things are not in perfect balance, there is a constant exchange of charged particles, and this is what comprises the electromagnetic spectrum, and enables the Universe to exist.
We do know why mass, charged particles do the things they do, we just don't know how.
Magnetism, gravity, the force that keeps electrons in orbit around a nucleus... All of them move another object from a distance, without any physical contact. That violates our physics rules.
correction: “and enables the Universe to (continue to ) exist.
Trying to unstuck the Saran Wrap generates more static electricity (an imbalance of charge, actually). The static has little to do with the Saran Wrap sticking to itself, and more to do with pulling it that way.
When you wrap up something with Saran Wrap, what causes it to stick to itself?
I'd say the only person authorized to do that would be someone who has been to at least one other place in the Universe, beyond our Solar System.
“Well, Bobby, today THE MR. SCIENCE SHOW is outdoors in our station’s parking lot between McDonald’s and a tanning salon. We’re going to examine the wonders of static electricity. ‘Is static electricity like a mosaic?’ You remember the MR. SCIENCE Motto - ‘Doing is Knowing!’ Today, we will rub a balloon against someone’s hair. We’ll need to make this experiment bigger so that it’s plain for our viewers to see. So, I’ve brought in the Goodyear Blimp to be our balloon. And, of course, the only person with a head big enough to take on this challenge is Joy Behar’s. Welcome Joy! Now, go over and rub that monstrosity of a head against the blimp.........Wow.......I thought they didn’t use hydrogen in balloons anymore. That was one big explosion. Oh, the humanity! Not the blimp....just the fact that people had to see Joy Behar’s head. Once again, science has triumphed over superstition! ‘Is static electricity like a mosaic?’ The answer is ‘No, static electricity is more like a Salvador Dali painting.’ Remember, viewers, mention THE MISTER SCIENCE SHOW at the Harrison Avenue McDonalds and receive 15 cents off a small order of fries!
Van de Graaff ping.
People can readily enough create mathematical formulas that describe “how.” God is the only entity who could ever explain “why.”
That said, even when we think we can explain ‘how’, mathematically or otherwise, we usually are only giving partial explanations.
Yes, we know that charges need to balance, but why is that? What exactly is a charge? You can say, ‘well it's what occurs when there is a differential accumulation of ‘positive’ and ‘negative’ particles, but how does any particle, electrons, protons, or whatever, have a ‘charge’? There is no mathematical formula, to my knowledge, that can explain this. Millikan could do his oil drop experiment (his grandson lived with a previous mentor of mine), and gives us some information about electrons, but we still have no idea what makes them attracted to protons, but repelled by other electrons. Saying that the ‘positive and negative charges have to balance out’, is just using our own designations for the properties that these particles have, without really knowing how those properties are defined mechanistically.
In short, we know very, very little. We compare ourselves to humans who didn't know what ‘electricity’ was, and who thought the world was flat, but in comparison to what there is to be known, we are just like neanderthals watching an eclipse.
Thanks for the Van de Graaff ping. We don’t really know how that device works, either, we just think we do.
Magic!!!
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