Several passages follow written at various times from 1747 up to 1998. All are on the topic of static electricity.

1. A passage from a turn of the century (the previous one) physics text.

The first is written by a physicist whose experiments are today cited my many physics teachers/profs as evidence that there are two types of charge or electrical matter. Notice that this text of his was published 100 years ago, but about 20 years after he first published his "famous" experiments (1879). Does it appear that he thinks his experiments were conclusive evidence that there are two types of charge? Does he indicate what the "right" explanation is? …or what the "true" explanation is?

2. Notes from articles published by E. H. Hall ranging from the first one on what later became known as the Hall Effect in 1879 to one of his last articles published in 1923.

The electron was "discovered" in 1897 by J. J. Thomson, a "fact" which was probably not realized until some time later (Nobel Prize in 1906). Thomson does not use the label, electron, in his article. As such, one has to ask, "What was it like to think about electricity without the benefit of sub-atomic particles moving around with different types of charge?" It seems clear from Hall's articles before 1897 that this is what he was doing. So do the Hall Effect results really tell us there are two types of charge or that there are particles carrying such charge? Note in the 1917 article Hall's position on the role of the newly "discovered" electrons in electric currents 20 years after their "discovery."

(Note: this section still to be expanded. More from articles by Hall before 1900 are on the way.)

3. Passages from physics texts of another turn of the century (the present one).

These are written by well-known physicists and current textbook authors. The intent is not to single out the work of a particular author but to give examples of modern, well-accepted texts. As you may know, these texts are typical and sell very well. Is the "right" or "true" answer to the question of whether or not there are two types of charge indicated in these texts? If so, is the basis for this "truth" or "rightness" explained or justified? What happened to the: "How do we know…? Why do we believe…?" concerning the two-charge model in these texts? Can this be found in any current introductory texts? Finally, does it appear from the statements in the texts that Ben Franklin chose arbitrary names (or arbitrarily chose names) for the two types of charge?

4. A letter from Ben Franklin introducing the terms, positive and negative.

Does it appear that Franklin was arbitrary in his naming convention? Was he was talking about two types of charge? How does your impression reading Franklin’s actual words compare with those from the modern text passages (#3)?

5. Another interesting letter by Franklin for your amusement.

6. Notes and passages from J. J. Thomson's article

As you read this look for where the notions of two types of charge and of particles carrying the charge come into play. Is he demonstrating that his results "prove" there are particles carrying a particular charge in the "cathode rays" or is he demonstrating that if there is such a thing as charged particles then he can very effectively explain his observations?

Some general comments and questions follow these passages.

PASSAGE #1

From A Textbook of Physics, Largely Experimental including the Harvard College "Descriptive List of Elementary Exercises in Physics" by Edwin Hall and Joseph Bergen on Henry Holt and Company, last copyright date 1897, printed 1899.

Page 482-3:

1. On a cold dry day rub a rod of gutta-percha or hard rubber with a catskin, and then present the rubbed part to small light pieces of paper or bits of thread lying on a table.

(2) Fasten two small pith-balls to the ends of a dry silk thread about 15 cm. long and suspend them by the middle of the thread from any convenient support.

Touch these balls with the freshly rubbed rod of gutta-percha. Note the behavior of the balls with respect to the rod just before they are touched and just after. Note also their behavior with respect to each other after they are touched by the rod.

If they act in an unusual manner, it is because they have become electrified, or "charged with electricity," by the rod.

(3) Rub a smooth glass rod vigorously with a piece of silk, and present the rubbed part to the suspended pith-balls still charged from the sealing-wax. Note their behavior before and after being touched by the glass.

What evidence do you find in these experiments that there are two kinds of electrification? Is there attraction or repulsion between bodies similarly electrified? Between oppositely electrified?

387. Nature and Kinds of Electricity. —There has been a difference in opinion as to whether electricity is or is not a substance. A century ago, when heat and light were believed to be weightless fluids, electricity was classed with them as a substance. Later, when it was shown that heat and light were not substances, but mere "modes of motion," in which the particles of matter are involved, the notion gained currency that electricity was a mode of motion, rather than a substance itself. During recent years belief in the existence of electric substance, or substances, has been growing again.

It is shown by the experiments preceding that there are two kinds, or states, of electrification, and that bodies may be oppositely electrified. But this does not prove that there are two kinds of electricity.

It has been held by some physicists that there is only one kind of electricity. According to their theory all bodies in their normal, apparently unelectrified, state are endowed with a certain quantity of electricity, any addition to which produces one kind of electrification, and any subtraction from which produces the opposite kind of electrification. This is the so-called one-fluid theory.

Other authorities have held that there are two kinds of electricity, and that in the normal state a body is endowed with equal quantities of the two kinds, which neutralize each other. According to this theory a state of electrification is produced by making either kind of electricity on the body exceed the other in amount, the nature of electrification being this or that according as one kind or the other of the two electricities is in the excess. This is the so-called two-fluid theory.

The nature of electricity, and the question whether there are two kinds, is still in debate, but in describing electrical phenomena there is great convenience in using the language of the two-fluid theory, and such language will be freely used in this book.

PASSAGES #2:

It is often stated today that it is the Hall Effect experiments which tell us that there are two types of charge. Yet, …the original Hall Effect experiments were conducted in 1879!!

In his original article ("On a New Action of the Magnet on Electric Currents" by E. H. Hall, Fellow of the Johns Hopkins University (at the time), pages 287 - 292 in the American Journal of Mathematics, Pure and Applied, Volume II, 1879), Hall does not specifically address the issue. He uses language such as "charged bodies" and "attraction and repulsion of the charges" which could be interpreted either as consistent with the one-fluid or the two-fluid model.

In the article Hall notes that James Clerk Maxwell in his book, Electricity and Magnetism, distinguishes between the electromotive force on electric currents and mechanical forces on conductors of electric currents in explaining the effect which had been observed of a magnet on a current carrying conductor. Hall says: "This statement seemed to me to be contrary to the most natural supposition in the case considered, taking into account the fact that a wire not bearing a current is in general not affected by a magnet and that a wire bearing a current is affected exactly in proportion to the strength of the current, while the size and, in general, the material of the wire are matters of indifference. Moreover in explaining the phenomena of statical electricity it is customary to say that charged bodies are attracted toward each other or the contrary solely by the attraction or repulsion of the charges for each other." (p. 287) He describes a series of experiments trying to tease out whether or not the magnetic effect acts on the conductor carrying the current solely or it acts through an effect on the current which results in an mechanical force on the conductor.

On page 289 Hall makes the statement: "If electricity is assumed to be an incompressible fluid, as some suspect it to be, we may conceive that the current of electricity flowing in a wire cannot be forced into one side of the wire or made to flow in any but a symmetrical manner." This appears to be compatible with a one-fluid way of thinking about electricity.

As he discusses his experiments and their results, he never refers to anything like charge of a specific sign. On page 290 he does use language such as, "If we regard an electric current as a single stream flowing from the positive to the negative pole" and later "from the negative to the positive pole," the positive poles being identified by the types of material in the battery (carbon as the positive pole and zinc as the negative pole. He even suggests that it remains to be seen "Whether …[his results have] any bearing upon the question of the absolute direction of the electric current…" On the last page he refers to "the velocity of the electricity in the gold."

Apparently, Hall, 20 years later after additional experimentation and thought, still considered the issue unresolved. What must electricity have been for him without the benefit of thinking about it in terms of little particles with two distinct types of charge in quantized chunks?

We have a glimpse of his inclinations in articles he wrote after the "discovery" of the electron. In an article by Hall titled, "A Possible Function of the Ions in the Electrical Conductivity of Metals" (Proceedings of the National Academy of Sciences of the USA, Volume 3, 1917, page 163 - ), he says:

"..a suggestion concerning electric conduction in metals…It rejects the free electron within the metal as the vehicle of the electric current and puts in their place for this function the metal ions, necessarily equally numerous with the free electrons."

"At very low temperatures the atoms of a metal are packed so closely that electrons pass readily from one to another in a continuous procession through the metal, if there is an applied electromotive force to maintain progression in one direction. Free electrons and metal ions, if indeed ionization exists at the lowest temperatures, need not be called into action here.

"With rising temperature the heat vibrations separate the atoms so that they are not always in conductive contact, and not very many degrees above absolute zero they are, on the average, so far apart that conductive contact between them is exceptional.

"In this state of things an electron will not in fact pass from one metal particle to another, even when they are in closes contact of a collision, unless one of these particles is an atom and the other an ion…"

He goes on to deal with three questions he considers important in the justification of his idea: "1. How numerous must the ions be in order to maintain currents of great density? 2. Would the conductive action of the ions conform to Ohm's Law? 3. What should be the temperature relations of conductivity, if it is due to ions?" In dealing with them he gives what he believes to be answers which continue to hold out the possibility that his "ion conduction" model is plausible. It is interesting to note that his model can be seen as an anticipation of the modern explanation of the apparent positive Hall current in semi-conductors.

PASSAGES #3

A. From Physics: Algebra and Trig (2^nd Edition) by Eugene Hecht on the Brooks/Cole Publishing Company, copyright 1998.

page 540:

"If we vigorously stroke a plastic pen on a woolen glove and hold the two apart, but close, fibers on the glove will stand on end, straining to reach up to the pen, making the attraction obvious. It was French botanist, C. Dufay, who first studied the repulsive interactions of electricity. He found that objects of the same material electrified in the same way repelled one another. Two pieces of glass rubbed with silk will repel each other, just as two chunks of amber rubbed with fur will (Fig. 15.1) Yet the charged glass will attract both the silk and the charged amber, and vice versa. Sometime around 1734, Dufay concluded "that there are two distinct Electricities"—two kinds of electric charge—and he was right. Summarized (Fig. 15.2) in contemporary terms: Like charges repel, unlike charges attract."

page 541:

"Today we follow Benjamin Franklin, arbitrarily calling the two kinds of charge positive and negative."

B. From Physics: Calculus , by Eugene Hecht on the Brooks/Cole Publishing Company, copyright 1996.

page 644:

"If we vigorously stroke a plastic pen on a woolen glove and hold the two apart but close, fibers on the glove will stand on end, straining to reach up to the pen, making the attraction obvious. It was French botanist, C. Dufay, who first studied the repulsive interactions of electricity. He found that objects of the same material electrified in the same way repelled one another. Two pieces of glass rubbed with silk will repel each other, just as two chunks of amber rubbed with fur will (Fig. 17.1) Yet the charged glass will attract both the silk and the charged amber, and vice versa. Sometime around 1734, Dufay concluded "that there are two distinct Electricities"—two kinds of electric charge—and he was quite right. Summarized in contemporary terms: Like charges repel, unlike charges attract." (Fig. 17.2)

From further down on page 644:

"Today we follow Benjamin Franklin's lead, arbitrarily calling the two kinds of charge positive and negative."

C. From Physics, Volume 2 by Halliday, Resnick and Krane on John Wiley and Sons, Inc., copyright 1992.

pages 594 and 595:

"…When we say that a body is "charged" we mean that it has a charge imbalance…Charged bodies exert forces on each other…We explain all of this by saying there are two kinds of charge…The positive and negative labels for electric charge are due to Benjamin Franklin (1706 - 1790)…"

D. From Physics for Scientists and Engineers (Volume 2, 3^rd Edition) by Paul Tipler on Worth Publishers, copyright (1991).

page 599:

"When we rub the plastic rod with fur or the glass rod with silk, we cause the rod to become "electrified" or "charged." … The great American statesman and scientist Benjamin Franklin proposed a model explaining why this is so. He suggested that every object has a "normal" amount of electricity and that, when two objects are rubbed together, some of this electricity can be transferred from one of the objects to the other. This leaves one with an excess amount of electricity and the other with an equal deficiency. Franklin described the resulting charges with plus and minus signs….Today, we know that when glass is rubbed with silk, electrons are transferred from the glass to the silk, leaving the silk with an excess number of electrons and the rod with a deficiency. According to Franklin's classification, which we still use, the silk is negatively charged…"

E. From Physics for Scientists and Engineers (4^th Edition) by Raymond Serway on Saunders College Publishing, copyright (1996).

pages 649 - 650:

"A number of simple experiments demonstrate the existence of electric forces and charges. For example, after running a comb through your hair on a dry day…Another simple experiment is to rub an inflated balloon with wool…You can easily electrify your body by vigorously rubbing your shoes on a wool rug.

"In a systematic series of simple experiments, it is found that there are two kinds of electric charges, which were given the names positive and negative by Benjamin Franklin (1706 - 1790)…To demonstrate this fact, consider a hard rubber rod that has been rubbed with fur…When a glass rod that has been rubbed with silk is brought near the rubber rod, the rubber rod is attracted toward the glass rod. On the other hand, if two charged rubber rods (or two charged glass rods) are brought near each other, as in Figure 23.1b, the force between them is repulsive. This observation shows that the rubber and glass are in two states of electrification. On the basis of these observations, we conclude that like charges repel one another and unlike charges attract one another. Using the convention suggested by Franklin, the electric charge on the glass rod is called positive and that on the rubber rod is called negative."

"Another important aspect of Franklin's model of electricity is the implication that electric charge is always conserved…The electrified state is due to a transfer of charge from one body to the other…We now know from our understanding of atomic structure that it is the negatively charged electrons that are transferred from the glass to the silk…"

F. From Physics (4^th Edition) by Cutnell and Johnson on John Wiley and Sons, Inc., copyright 1998.

page 522 - 524:

"The electrical nature of matter is inherent in the atoms of all substances…Like mass, electric charge, is an intrinsic property of protons and electrons, and only two types of charge have been discovered, positive and negative… It is a fundamental characteristic of electric charges that like charges repel and unlike charges attract each other."

In this last passage, no mention of really how we "know" these things or of Franklin or Dufay or that simple experiments "tell" us there are two types of charge. …just the current canonical explanation of the "simple experiments" in modern Physicists' terms as given "truth."

PASSAGE #4

THE FIRST MENTION OF PLUS AND MINUS

To Peter Collinson: Philadelphia, 11 July 1747

Dear Sir:

1. A person standing on wax and rubbing a glass tube, and another person on wax drawing the fire, they will both of them (provided they do not stand so as to touch one another) appear to be electrized to a person standing on the floor: that is, he will perceive a spark on approaching each of them with his knuckle.

2. But if the persons on wax touch one another during the exciting of the tube, neither of them will appear to be electrized.

3. If they touch one another after exciting the tube, and drawing the fire as aforesaid, there will be a stronger spark between them than was between either of them and the person on the floor.

4. After such strong spark neither of them discover any electricity.

These appearances we attempt to account for thus: We suppose, as aforesaid, that electrical fire is a common element, of which every one of the three persons above mentioned has his equal share, before any operation is begun with the tube. A, who stands on wax and rubs the tube, collects the electrical fire from himself into the glass; and, his communication with the common stock being cut off by the wax, his body is not immediately supplied. B (who stands on wax likewise), passing his knuckle along near the tube, receives the fire which was collected by the glass from A; and his communication with the common stock being likewise cut off, he retains the additional quantity received. To C, standing on the floor, both appear to be electrized; for he, having only the middle quantity of electrical fire receives a spark upon approaching B, who has an over quantity; but gives one to A, who has an underquantity. If A and B approach to touch each other, the spark is stronger, because the difference between them is greater. After such touch there is no spark between either of them and C, because the electrical fire in all is reduced to the original equality. If they touch while electrizing, the equality is never destroyed, the fire only circulating. Hence, have arisen some new terms among us: we say B (and bodies like circumstanced) is electrized positively; A, negatively. Or rather, B is electrized plus; A, minus.

B. Franklin

PASSAGE #5

A SHOCKING REVELATION

Dear Friend,

I have lately made an experiment that I desire never to repeat. Two nights ago, being about to kill a turkey by the shock from two large glass jars, containing as much electrical fire as forty common phials, I inadvertently took the whole through my own arms and body, by receiving the fire from the united top wires with one hand while the other held a chain connected with the outside of both jars. The company present (whose talking to me and to one another, I suppose, occasioned my inattention to what I was about) say that the flash was very great, and the crack as loud as a pistol, yet, my senses being instantly gone, I neither saw the one nor heard the other; nor did I feel the stroke in my hand, though afterwards found it raised a round swelling where the fire entered, as big as half a pistol bullet, by which you may judge the quickness of the electrical fire, which by this instance seems to be greater than that of sound, light, or animal sensation.

What I can remember of the matter is that I was about to try whether the bottles or jars were fully charged by the strength and length to my hand, as I commonly used to do, and which I might safely enough have done if I had not held the chain in the other hand. I then felt what I know not how to describe... a universal blow throughout my whole body from head to foot, which seemed within as well as without; after which the first thing I took notice of was a violent quick shaking of my body, which gradually remitting, my sense as gradually returned, and then I thought the bottles must be discharged, but could not conceive how, till at last I perceived the chain in my hand, and recollected what I had been about to do. That part of my hand and fingers which held the chain was left white, as though the blood had been driven out, and remained so eight or ten minutes after, feeling like dead flesh; and I had a numbness in my arms and back of my neck, which continued till the next morning, but wore off. Nothing remains now of the shock but a soreness in my breastbone, which feels as if it had been bruised. I did not fall, but suppose I should have been knocked down if I had received the stroke in my head. The whole was over in a minute.

You may communicate this to Governor Bowdoin as a caution to him, but do not make it more public, for I am ashamed to have been guilty of so notorious a blunder; a match for that of the Irishman whom my sister told me of, who, to divert his wife, poured the bottle of gun powder on the live coal; or that of the other, who, being about to steal powder, made a hole in the cask with a hot iron.

B. Franklin

6. Excerpts from J. J. Thomson's article (1897)

The following are taken from the paper published in the Philosophical Magazine, vol. 44, series 5, 1897, which starts on page 293. A significant portion of Thomson's article can be found in: Great Experiments in Physics, edited by Morris Shamos, Henry Holt and Company, New York, 1959.

"The experiments discussed in this paper were undertaken in the hope of gaining some information as to the nature of the cathode rays. The most diverse opinions are held as to these rays; according the almost unanimous opinion of German physicists they are due to some process in the ether to which--inasmuch as in a uniform magnetic field their course is circular and not rectilinear--no phenomenon hitherto observed is analogous: another view of these rays is that, so far from being wholly ethereal, they are in fact wholly material, and that they mark the paths of particles of matter charged with negative electricity. It would seem at first sight that it ought not to be difficult to discriminate between views so different, yet experience shows that this is not the case, as amongst the physicists who have most deeply studied the subject can be found supporters of either theory.

"The electrified-particle theory has for purposes of research a great advantage over the ethereal theory, since it is definite and its consequences can be predicted; with the ethereal theory it is impossible to predict what will happen under any given circumstances, as on this theory we are dealing with hitherto unobserved phenomena in the ether, of whose laws we are ignorant.

"The following experiments were made to test some of the consequences of the electrified-particle theory."

… Thomson describes having repeated an experiment previously performed by Perrin…

"This experiment proves that something charged with negative electricity is shot off from the cathode, traveling at right angles to it, and that this something is deflected by a magnet; it is open, however to the objection that it does not prove that the cause of the electrification in the electroscope has anything to do with the cathode rays. Not the supporters of the ethereal theory do not deny that electrified particles are shot off from the cathode; they deny, however, that these charged particles have any more to do with the cathode rays than a rifle ball has with the flash when a rifle is fired…."

Thomson then describes a modified version of the experiment which "shows that however we twist and deflect the cathode rays by magnetic forces, the negative electrification follows the same path as the rays, and that this negative electrification is indissolubly connected with the cathode rays." Next he writes:

"An objection very generally urged against the view that the cathode rays are negatively electrified particles, is that hitherto no deflection of the rays has been observed under a small electrostatic force, and though the rays are deflected when they pass near electrodes connected with sources of large differences of potential, such as induction coils or electrical machines, the deflection in this case is regarded by the supporters of the ethereal theory as due to the discharge passing between the electrodes, and not primarily to the electrostatic field."

He points out that he has been able to see such an effect but only in a well evacuated tube. After describing the specifics of this new experiment and what he observed, he writes:

"As the cathode rays carry a charge of negative electricity, are deflected by an electrostatic force as if they were negatively electrified, and are acted on by a magnetic force in just the way in which this force would act on a negatively electrified body moving along the path of these rays, I can see no escape from the conclusion that they are charges of negative electricity carried by particles of matter. The question next arises, what are these particles? … To shed some light on this point, I have made a series of measurements of the ratio of the mass of these particles to the charge carried by it."

Thomson concludes: "From these determinations we see that the value of m/e is independent of the nature of the gas [residual gas in the cathode ray tubes used], and that its value [about] 0.0000001 is very small compared with the value 0.0001, whish is the smallest value of this quantity previously known, and which is the value for the hydrogen ion in electrolysis. [We would now call this latter object the proton.]"

"The two fundamental points about these carriers seem to be to be (1) that these carriers are the same whatever the gas through which the discharge passes, (2) that the mean free paths depend upon nothing but the density of the medium traversed by these rays."

In this last statement he seems to be saying (1) that the charge carrying particles seem constituted independently of the gas in the tubes and (2) that they seem to interact with the gas as particles passing through the gas. Just before this in the paper Thomson has indicated "The carrier, then, must be small compared with ordinary molecules." This statement is based on the apparent mean free path of these carriers.

From these excerpts it seems that one could think in terms of either a one or a two-fluid model for electricity. After all he is still using the term, electrification. The experiment itself does not seem to make demands logically concerning which model of electricity is used. It also seems that the particulate nature of matter is already accepted, hence these experimental observations are not where the notion that matter is made of small particles originated. Could one explain the results using a single-fluid model of electricity and some sort of continuous medium notion of matter as opposed to a discrete particle notion of matter?

It seems that much of our modern notions on this subject of sub-atomic charge carrying particles may have won acceptance in the scientific community not so much because it was the ONLY conclusion possible to fit the observations, but because one could make such compelling demonstrations starting from certain assumptions. Maybe these really are non-unique explanations which both can fit our observations, but, given this non-uniqueness, cannot tell us what "reality" really is. Coupled with the fact that the history of science can be seen as a sequence of models, one replacing another, one must reconsider the status of our explanations of matter and electricity.

Other quotations come to mind in this respect:

"Physical concepts are the free creations of the human mind and are not, however it may seem, uniquely determined by the external world."--A. Einstein in The Evolution of Physics with L. Infeld, 1938.

"As a result of modern research in physics, the ambition and hope, still cherished by most authorities of the last century, that physical science could offer a photographic picture and true image of reality had to be abandoned." --M. Jammer in Concepts of Force, 1957 (recently re-published by Dover, 1999).

"Every [person's] world picture is and always remains a construct of [her or his] mind and cannot be proved to have any other existence."--E. Schrodinger in Mind and Matter, 1958.

"Don't mistake your watermelon for the universe." --K. Amdahl in There Are No Electrons, 1991.

"If what we regard as real depends on our theory, how can we make reality the basis of our philosophy? ...But we cannot distinguish what is real about the universe without a theory...it makes no sense to ask if it corresponds to reality, because we do not know what reality is independent of a theory."--S. Hawking in Black Holes and Baby Universes, 1993.

These historically significant papers by Hall and Thomson reveal the speculative and tentative nature of science, not present in modern texts. Yet, we wonder why our students are not more thoughtful and reflective. We wonder why our students demand specific definite answers in science instead of questions that invite them to speculate. Could it be that their view of science and the nature of its knowledge is not that of these scientists of the past? If we continue teaching this way how long will it be until the science of the scientists is not the speculative, tentative, exploratory science of the scientists of the past?

General Questions and Comments:

Is the issue of whether or not electricity is a single fluid or two fluids resolved today? Most scientists would say, yes. Was it resolved via consideration of the demonstrations typically referred to in today's textbooks? No! If it were so obvious from these demonstrations, Franklin and Hall would have spoken and written differently about electricity than they did. Do most scientists today know how the issue was resolved? Apparently not or why would they be writing today's texts as they do and then defer to Hall's experiments when challenged?

One is left wondering if the examples we give in any textbook chapters on electricity (static or current) justify the conclusions associated with them. What about other topics in Physics? …or other topics in any subject?

What can we expect the impact of modern textbooks on students is likely to be when it comes to their thinking about the "truth" with respect to electrical charge, what the "right" answers are in general and where these "true" or "right" answers might come from in science?

"I didn't realize that the so-called "geniuses" came up with their ideas through the same process we went through in class. I’d always figured they just got it because they were geniuses."

So where does the truth come from, where does the right answer come from? Are there such things as truth and the right answer? How are they determined? Are such things clearly discernable from typical physics texts? Should they be clearly discernable from physics texts? What are the consequences of treating knowledge in the way current textbooks treat it?

For more of the original source material on electricity during this period in history:

Heilbron, J. L. Electricity in the 17^th & 18^th Centuries: A Study of Early Modern Physics. University of California Press, Berkeley, CA, 1979. (recently re-published by Dover, 1999)

Is this the only topic on which "we" have stumbled? On how many topics have we stumbled? Compare the descriptions of Newton and his work in textbooks with original source material as is available in Westfal’s biography of Newton, Never at rest (Oxford University Press) or the writings of I. Bernard Cohen from Harvard.

How much of this garbled history and authoritarian statement of "fact" is there in our textbooks? How much can we tolerate before we have created a damaging effect on the population (including our future majors) of which we should not be proud? It seems we are falling into the "trap" Paul Feyerabend refers to in his essay "How to Defend Society Against Science" published in Introductory Readings in the Philosophy of Science (Klemke, Hollinger, Kline eds. Prometheus Books, Buffalo, NY 1988). The essay was originally published in the journal, Radical Philosophy (no. 11, 1975, pp 3 – 8).

Reading the original works of Hall and Thomson was like a breath of fresh air compared to the modern textbooks. It seems the status of entities we discuss and use to explain the phenomena of physics should be taken as very much different than we imply in today's texts. Electrons, charge, electric current and force seem to be ideas used to explain observations, but not necessarily directly observable themselves. Is it then ethical to write and use texts and conduct class in such a way as to let students assume they must be inferior if the existence of these things is not obvious to them? This appears to be what happens to many students who experience science instruction.

Is it not possible for textbook authors to be more scholarly about the history and status of the ideas? Is it not their obligation? What is our obligation in this respect? What effect does this lack of scholarship have on the students who use their books? Are there underlying reasons for the texts and the physicists' canonical version of the history physics not matching original source material? Are there underlying reasons for the rationale behind the physicists' canonical explanation of the phenomena being kept hidden from students? Are there reasons why the students are presented with authoritarian statements of Truth and presented with faulty logic to support it? What is the purpose of such practices? Whose purpose do they serve? Who loses because of these practices? Who gains? What is lost because of these practices?

A look at James Loewen's book, Lies My Teacher Told Me, (The New Press, 1995) on teaching U.S. history and David Gabbard's book, Knowledge and Power in the Global Economy: Politics and the Rhetoric of School Reform (Lawrence Erlbaum Associates, 1999) might suggest ways of thinking about the questions in the last paragraph. As seems to be suggested in these books, such the paradoxical practices of science education can make sense, but at least one world-view in which they do make sense is serious cause for reflection on the current state of affairs.

Clearly, the point here is not whether or not the problem of one or two electricities has been solved. The issue is what students learn from us about the nature of knowledge and of the "enterprise" of science in how we treat the knowledge as we teach. They probably learn this better than any individual "piece" of knowledge we might be attempting to "teach."

Revised: 15 Dec 99