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our explanations and hides many important concepts such as charge separation, the density of imbalanced positive—negative charge, and the presence of voltage fields surrounding the imbalanced charges. These things are important even when the "static electricity" begins moving along as ant "STATIC ELECTRICITY" our explanations and hides many important _ "static electricity"? After all, they're static MISCONCEPTIONS concepts such as charge separation, the and unmoving, right? They sit there inside ah density of imbalanced positive-negative each atom. And each individual electron by William J. Beaty © 2005 charge, and the presence of voltage fields and proton carries a charge of "Static ome elementary science textbooks surrounding the imbalanced charges. _ electricity". Shouldn't we say that physical contain subtle errors which pose bar- These things are important even when the matter is partly made out of "static riers to students’ understanding. _ "static electricity" begins moving along as ___ electricity"? "Static electricity" is one subject whichis a current. But if we say that matter is made out of rife with errors. Since the errors in text- Electrostatics is not about "staticness". "static", then where are the sparks and books seem to act like "viruses" which can Instead, it's about charge and forces. crackling noises? There aren't any. Where "infect" our minds, I hope that the follow- Imagine if water was explained just as _ is the rising hair? There isn't any. This ing discussion will act as a sort of badly as static electricity. In that case, shows that the "staticness" is not an impor- "antivirus" (grin!). It should help those most people would believe in two special tant factor. Instead, the most important who read this webpage, and with luck my _ kinds of water called "static water" and factor is the balance of opposite charges. article might utilise some of the same Inside matter, the positive and negative rumour-dynamics as the viruses. charges are close together, and so their These ideas might take off and spread effects cancel out. Even though matter through the elementary education pop- is full of charges which are "static" and ulation and "immunise" large numbers Electrostatics is about unmoving, there is normally no "static of people against these particular mis- electricity" to be seen. conceptions. charge and about the It's about an imbalance between _ i opposite charges, not about staticness. Electrostatics: not "staticness" attract repel forces which Also, the presence of charged particles "Static electricity" is not electricity electric charge creates. is not such an important factor, since which is static. Instead, it is a collec- matter is full of them even when no tion of different electrical phenomena, "static electricity" appears. We need where: separated, imbalanced particle popula- * the amounts of positive and nega- tions before interesting things start to tive electric charge within a material are happen. Just having charged particles not perfectly equal. "current water". We'd wrongly insist that is not enough. * voltage is high and current is low. hydrostatics was the study of static water. How can we fix the confusion? Easy. * electrical forces (attraction and repul- In that case, only the hydraulics experts Don't call it "static". Instead, call it sion) are seen to reach across space. would realise that there's no such thing as_—_"charge imbalance". It's the net electric Widely spaced objects may attract or repel "static water": the so-called "static" water charge which is important. Or, put more each other. Hair might stand on end! is really just pressurised water. The — simply, it is the separation between posi- * electric fields (as opposed to magnetic experts would also know that "static water" tive and negative particles which is the fields) become very important (electric can even flow along, since pressurised _ basis for "static electricity". fields are also called "electrostatic fields". water need not remain still or "static". When quantities of protons are separated or "e-fields' Hydrostatics still applies to water when it from electrons across a large distance, then Electrostatics is about charge and about begins to flow. In a similar way, "static we'll get sparks and rising hair. Call this the attract-repel forces which electric _ electricity" has everything to do with pres- "electric charge", not "static charge," since charge creates. The motion or "staticness" surised charge and nothing to do with _ the imbalance remains the same even when of the charge is irrelevant: after all, the "electricity at rest". the charges flow along very non-statically. forces are still there, even when the charges Whenever these opposite charges in mat- start flowing. Charges which are separated An imbalance of opposite charges ter are sorted out and separated into groups or imbalanced can sometimes flow along, Here's another problem with the usual _ of positive and negative, then we say that yet the "static" effects are undiminished "static electricity" concept. First, think "static electricity" has been generated. when the current begins. In other words, it about everyday matter. Down inside its | What does this have to do with the charges is perfectly possible to create flows of so- atoms, everyday matter contains equal remaining still or static? Nothing! called "static" electricity. numbers of positive and negative charges In fact, if the charge imbalance can be It is very misleading to concentrate on (protons and electrons) which are very made to flow along, it will still retain all of the "staticness" of the charges, as it derails close together. Are these charges the its unusual characteristics. It will still "STATIC ELECTRICITY" a current. Electrostatics is not about "staticness". Instead, it's about charge and forces. Imagine if water was explained just as badly as static electricity. In that case, most people would believe in two special kinds of water called "static water" and charge and about the attract-repel forces which electric charge creates. "current water". We'd wrongly insist that hydrostatics was the study of static water. In that case, only the hydraulics experts would realise that there's no such thing as "static water": the so-called "static" water is really just pressurised water. The experts would also know that "static water" can even flow along, since pressurised water need not remain still or "static". Hydrostatics still applies to water when it begins to flow. In a similar way, "static electricity" has everything to do with pres- surised charge and nothing to do with "electricity at rest". An imbalance of opposite charges Here's another problem with the usual "static electricity" concept. First, think about everyday matter. Down inside its atoms, everyday matter contains equal numbers of positive and negative charges (protons and electrons) which are very close together. Are these charges the NEXUS = 41 by William J. Beaty © 2005 Electrostatics is about OCTOBER — NOVEMBER 2005 www.nexusmagazine.com