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Nahum Kipnis

University of Minnesota - Twin Cities, History of Science, Technology, and Medicine, Alumnus

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I am a historian of science (40 years and going) and a physics teacher (31 years but teach no longer). I devoted a number of years since 1986 to marry these two professions so as to improve students' learning, primarily by instructing science teachers and creating teaching materials. See the samples of courses for teachers and teaching materials:

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Papers by Nahum Kipnis

The 'Historical-Investigative' Approach to Teaching Science

Science& Education, 1996

The paper describes the author's experience in using the history of science in teaching physics t... more The paper describes the author's experience in using the history of science in teaching physics to science teachers. lt was found that history becomes more useful to teachers when explicitly combined with 'investigative' experimentation, which, in turn. can benefit from various uses of the history of science.

Luigi Galvani and the Debate on Animal Electricity, 1791-1800

Annals of Science, 1987

Galvani's discovery provoked an animated debate that lasted for about a decade. So far. historian... more Galvani's discovery provoked an animated debate that lasted for about a decade. So far. historians have studied only the controversy between Volta and Galvani. I show that a more extensive examination of the response to Galvani's treatise reveals a number of important issues that were characteristic of contemporary physics and physiology but have not much attracted the attention of historians. In particular, the analysis shows the need to reappraise Galvani's role in establishing animal electricity.

Luigi Galvani and the Debate on Animal Electricity 1987

Galvani's discovery provoked an animated debate that lasted for about a decade. So far. historian... more Galvani's discovery provoked an animated debate that lasted for about a decade. So far. historians have studied only the controversy between Voltd and Galrani. I show that a mare extensive examination of the response to Galvani's treatise rcveals a number of im~ortant issues that were characteristic of the contcmporary. . animal electricity. Contents I. Introduction

l8th-century Instruments in the Classroom

Kipnis, N. & Pogrebysskaya, E._Two problems in physical optics at the turn of 18th and 19th centuries

Experimental Foundations of Acoustics and Hearing_Program

Early theories of X-rays

Studying the establishing of the nature of X rays appears to provide interesting insights into th... more Studying the establishing of the nature of X rays appears to provide interesting insights into the ways that new physical theories are offered and adopted. This paper deals only with the initial stage of this process, which encompasses the first two years after Roentgen's discovery. This period is selected because it was long enough for all competing theories to emerge and for physicists to realize that the solution of the problem was not at all close.

Experimental Foundations of Optics and Vision

The second NSF-supported Bakken summer institute for secondary school teachers of physical and bi... more The second NSF-supported Bakken summer institute for secondary school teachers of physical and biological sciences from the project "Physics and Life" be on the Experimental Foundations of Optics and Vision. The course will be taught by Dr. Nahum Kipnis, science educator of The Bakken and several guest lecturers. The institute will run from June 21 to July 19, 1990. Participants will receive 4 graduate University of Minnesota credits for Physics 5940: "Physics for High School Teachers: Experimental Foundations and Historical Perspectives." The course will be based on historical materials, including reproduction of historical experiments.

Laboratory Experiments Reproducing Discoveries in Current Electricity

Experimental Foundations of Bio-electricity_Program

Thomas Young and the Discovery of The Principle of Interference of Light_1985

The Reception of Fresnel's Principle of Interference by Paris Academy of Sciences (1816-1824)_1983

The competition between the emission and wave theories of light in the early nineteenth century h... more The competition between the emission and wave theories of light in the early nineteenth century has provided historians with a difficult problem to solve: why did Thomas Young fail to establish the wave theory of light, while Augustine Fresnel succeeded? The response of Paris academicians to Fresnel&#39;s principle provides a partial answer that the situation in Paris c. 1816 was more favorable to the new theory than that in London c. 1804. In particular, several academicians agreed to accept the principle of interference as a mathematical principle, although they rejected the wave theory of light.

Historical Experiments in Secondary School_Hungary

This paper describes a new method of combining the history of science with teaching physics in se... more This paper describes a new method of combining the history of science with teaching physics in secondary school that has been developed at the Bakken Library and Museum in Minneapolis and applied in teaching science teachers. Its purpose was to improve teachers' understanding of physics and to give them a teaching technique that can make learning of physics both effective and enjoyable. I call my method historical-investigative because it has two components: historical approach to science and investigative experimentation. While each of them is usable separately, their combination can provide a number of additional benefits. This method is described in detail in my book Rediscovering Optics, a sample from which is given in the Appendix. The method, however, is not limited to optics: I use it also with electricity, acoustics, and other topics~ while some of my students apply it not only in physics but also in chemistry, astronomy, biology, and other subjects.

Qualitative Physics in High School

Until the second half of the nineteenth century physics was primarily a qualitative science, with... more Until the second half of the nineteenth century physics was primarily a qualitative science, with a considerable body of knowledge obtained from qualitative experiments. This suggests the idea to begin teaching physics as a qualitative science, and to move on to the quantitative mode only after students learn how to obseiVe phenomena and fonnulate qualitative laws. Such technique is used in teaching science teachers at the Bakken Museum in Minneapolis. This approach helps students in understanding physical concepts, developing a physical way of thinking, and realizing the relationship between physics and mathematics.

Blending Physics with History

The paper describes the author's experience in using the history of science in teaching physi... more The paper describes the author's experience in using the history of science in teaching physics to science teachers. It was found that history becomes more useful to teachers when it is closely combined with investigative experimentation. This approach can improve students' understanding of the subject matter and of the nature of science.

From "β-rays" to "electron

History of Modern Physics, 2002

A History of Science Approach to the Nature of Science: Learning Science by Rediscovering it

Science & Technology Education Library

My interest in teaching the nature of science came from attempts to integrate history into physic... more My interest in teaching the nature of science came from attempts to integrate history into physics courses for teachers at the Bakken Library and Museum beginning in 1985. My background in the history of science and in teaching physics appeared ideal for helping teachers transform the science of facts and equations they typically teach into science as a human activity. Michael Matthews labels this a distinction between "technical" and "liberal" science. The trouble was that many course participants had degrees in biology or chemistry, and were unfamiliar even with "technical physics." Having no foundation to build on, I choose to teach both, and the question was how to do it. By that time, I had already been convinced that physics could be taught to all students by shifting the emphasis from the memorization of facts to developing skills of thinking, reasoning, and systematic purposeful work by students. I decided to try investigative laboratory experiments as one of the main vehicles for achieving this purpose. Teachers conducted experiments in groups and individually. When they brought the new labs to their schools, they appealed to the majority of students and raised their interest in learning science. The peculiar feature of these laboratory activities was that many of them recreated historical experiments. The idea of reproducing historical experiments in the classroom came from Devons and Hartmann (1970). I could have achieved my goal with other experiments as well, but I wanted to use history as much as possible, and the historical experiments did have an advantage over the "real-life investigations" practiced by some teachers, such as finding the cause of the clogged classroom sink or determining which paper towel is most absorbent. First, with the historical approach, the result is always known to the instructor, which is not the case with the sink and towels. Second, a historical experiment can be chosen so as to help teach a narrow scientific topic, while most real-life phenomena are too complex and complicated for students' study. Third, for the first two reasons, the students' chances to succeed are higher with the historical experiments than with the other ones. Finally, a success in repeating a historical scientific discovery may boost students' self-confidence much more than in fixing the plumbing. It is not that technological problems are unusable; if carefully chosen, they are. However, it is easier to learn the necessary investigative skills in historical scientific experiments and then use them to tackle the frequently more complicated problems in technology.

Discovery of the principle of interference of light

History of the Principle of Interference of Light, 1991

As stated in 1.3, Young wanted to build a mathematical theory of periodical colors. Before examin... more

Thomas Young and the problem of intersecting sounds

History of the Principle of Interference of Light, 1991

There is no agreement among historians about the meaning of Young’s discovery of the concept of i... more There is no agreement among historians about the meaning of Young’s discovery of the concept of interference. Robert Silliman, for instance, stated that, “The novelty of Young’s discovery lay not in the general concept of interference but in its application to optics. More than a century before, the idea of interference had been used by Newton himself… The idea also found an important application in acoustics.” 1 The early Young scholars did not view this fact as diminishing the importance of his discovery.

The response to the principle of interference (1801–1815)

History of the Principle of Interference of Light, 1991

It has long been considered an historical anomaly that Young’s wave theory was not accepted befor... more It has long been considered an historical anomaly that Young’s wave theory was not accepted before 1816. Some scholars claim, however, that this response was not at all unusual, since the theory did not, in fact, deserve to be accepted.1 As I have shown above, however, Young’s theory was not so severely flawed that it should have been completely ignored

The 'Historical-Investigative' Approach to Teaching Science

Science& Education, 1996

The paper describes the author's experience in using the history of science in teaching physics t... more The paper describes the author's experience in using the history of science in teaching physics to science teachers. lt was found that history becomes more useful to teachers when explicitly combined with 'investigative' experimentation, which, in turn. can benefit from various uses of the history of science.

Luigi Galvani and the Debate on Animal Electricity, 1791-1800

Annals of Science, 1987

Galvani's discovery provoked an animated debate that lasted for about a decade. So far. historian... more Galvani's discovery provoked an animated debate that lasted for about a decade. So far. historians have studied only the controversy between Volta and Galvani. I show that a more extensive examination of the response to Galvani's treatise reveals a number of important issues that were characteristic of contemporary physics and physiology but have not much attracted the attention of historians. In particular, the analysis shows the need to reappraise Galvani's role in establishing animal electricity.

Luigi Galvani and the Debate on Animal Electricity 1987

Galvani's discovery provoked an animated debate that lasted for about a decade. So far. historian... more Galvani's discovery provoked an animated debate that lasted for about a decade. So far. historians have studied only the controversy between Voltd and Galrani. I show that a mare extensive examination of the response to Galvani's treatise rcveals a number of im~ortant issues that were characteristic of the contcmporary. . animal electricity. Contents I. Introduction

l8th-century Instruments in the Classroom

Kipnis, N. & Pogrebysskaya, E._Two problems in physical optics at the turn of 18th and 19th centuries

Experimental Foundations of Acoustics and Hearing_Program

Early theories of X-rays

Studying the establishing of the nature of X rays appears to provide interesting insights into th... more Studying the establishing of the nature of X rays appears to provide interesting insights into the ways that new physical theories are offered and adopted. This paper deals only with the initial stage of this process, which encompasses the first two years after Roentgen's discovery. This period is selected because it was long enough for all competing theories to emerge and for physicists to realize that the solution of the problem was not at all close.

Experimental Foundations of Optics and Vision

The second NSF-supported Bakken summer institute for secondary school teachers of physical and bi... more The second NSF-supported Bakken summer institute for secondary school teachers of physical and biological sciences from the project "Physics and Life" be on the Experimental Foundations of Optics and Vision. The course will be taught by Dr. Nahum Kipnis, science educator of The Bakken and several guest lecturers. The institute will run from June 21 to July 19, 1990. Participants will receive 4 graduate University of Minnesota credits for Physics 5940: "Physics for High School Teachers: Experimental Foundations and Historical Perspectives." The course will be based on historical materials, including reproduction of historical experiments.

Laboratory Experiments Reproducing Discoveries in Current Electricity

Experimental Foundations of Bio-electricity_Program

Thomas Young and the Discovery of The Principle of Interference of Light_1985

The Reception of Fresnel's Principle of Interference by Paris Academy of Sciences (1816-1824)_1983

The competition between the emission and wave theories of light in the early nineteenth century h... more The competition between the emission and wave theories of light in the early nineteenth century has provided historians with a difficult problem to solve: why did Thomas Young fail to establish the wave theory of light, while Augustine Fresnel succeeded? The response of Paris academicians to Fresnel&#39;s principle provides a partial answer that the situation in Paris c. 1816 was more favorable to the new theory than that in London c. 1804. In particular, several academicians agreed to accept the principle of interference as a mathematical principle, although they rejected the wave theory of light.

Historical Experiments in Secondary School_Hungary

This paper describes a new method of combining the history of science with teaching physics in se... more This paper describes a new method of combining the history of science with teaching physics in secondary school that has been developed at the Bakken Library and Museum in Minneapolis and applied in teaching science teachers. Its purpose was to improve teachers' understanding of physics and to give them a teaching technique that can make learning of physics both effective and enjoyable. I call my method historical-investigative because it has two components: historical approach to science and investigative experimentation. While each of them is usable separately, their combination can provide a number of additional benefits. This method is described in detail in my book Rediscovering Optics, a sample from which is given in the Appendix. The method, however, is not limited to optics: I use it also with electricity, acoustics, and other topics~ while some of my students apply it not only in physics but also in chemistry, astronomy, biology, and other subjects.

Qualitative Physics in High School

Until the second half of the nineteenth century physics was primarily a qualitative science, with... more Until the second half of the nineteenth century physics was primarily a qualitative science, with a considerable body of knowledge obtained from qualitative experiments. This suggests the idea to begin teaching physics as a qualitative science, and to move on to the quantitative mode only after students learn how to obseiVe phenomena and fonnulate qualitative laws. Such technique is used in teaching science teachers at the Bakken Museum in Minneapolis. This approach helps students in understanding physical concepts, developing a physical way of thinking, and realizing the relationship between physics and mathematics.

Blending Physics with History

The paper describes the author's experience in using the history of science in teaching physi... more The paper describes the author's experience in using the history of science in teaching physics to science teachers. It was found that history becomes more useful to teachers when it is closely combined with investigative experimentation. This approach can improve students' understanding of the subject matter and of the nature of science.

From "β-rays" to "electron

History of Modern Physics, 2002

A History of Science Approach to the Nature of Science: Learning Science by Rediscovering it

Science & Technology Education Library

My interest in teaching the nature of science came from attempts to integrate history into physic... more My interest in teaching the nature of science came from attempts to integrate history into physics courses for teachers at the Bakken Library and Museum beginning in 1985. My background in the history of science and in teaching physics appeared ideal for helping teachers transform the science of facts and equations they typically teach into science as a human activity. Michael Matthews labels this a distinction between "technical" and "liberal" science. The trouble was that many course participants had degrees in biology or chemistry, and were unfamiliar even with "technical physics." Having no foundation to build on, I choose to teach both, and the question was how to do it. By that time, I had already been convinced that physics could be taught to all students by shifting the emphasis from the memorization of facts to developing skills of thinking, reasoning, and systematic purposeful work by students. I decided to try investigative laboratory experiments as one of the main vehicles for achieving this purpose. Teachers conducted experiments in groups and individually. When they brought the new labs to their schools, they appealed to the majority of students and raised their interest in learning science. The peculiar feature of these laboratory activities was that many of them recreated historical experiments. The idea of reproducing historical experiments in the classroom came from Devons and Hartmann (1970). I could have achieved my goal with other experiments as well, but I wanted to use history as much as possible, and the historical experiments did have an advantage over the "real-life investigations" practiced by some teachers, such as finding the cause of the clogged classroom sink or determining which paper towel is most absorbent. First, with the historical approach, the result is always known to the instructor, which is not the case with the sink and towels. Second, a historical experiment can be chosen so as to help teach a narrow scientific topic, while most real-life phenomena are too complex and complicated for students' study. Third, for the first two reasons, the students' chances to succeed are higher with the historical experiments than with the other ones. Finally, a success in repeating a historical scientific discovery may boost students' self-confidence much more than in fixing the plumbing. It is not that technological problems are unusable; if carefully chosen, they are. However, it is easier to learn the necessary investigative skills in historical scientific experiments and then use them to tackle the frequently more complicated problems in technology.

Discovery of the principle of interference of light

History of the Principle of Interference of Light, 1991

As stated in 1.3, Young wanted to build a mathematical theory of periodical colors. Before examin... more

Thomas Young and the problem of intersecting sounds

History of the Principle of Interference of Light, 1991

There is no agreement among historians about the meaning of Young’s discovery of the concept of i... more There is no agreement among historians about the meaning of Young’s discovery of the concept of interference. Robert Silliman, for instance, stated that, “The novelty of Young’s discovery lay not in the general concept of interference but in its application to optics. More than a century before, the idea of interference had been used by Newton himself… The idea also found an important application in acoustics.” 1 The early Young scholars did not view this fact as diminishing the importance of his discovery.

The response to the principle of interference (1801–1815)

History of the Principle of Interference of Light, 1991

It has long been considered an historical anomaly that Young’s wave theory was not accepted befor... more It has long been considered an historical anomaly that Young’s wave theory was not accepted before 1816. Some scholars claim, however, that this response was not at all unusual, since the theory did not, in fact, deserve to be accepted.1 As I have shown above, however, Young’s theory was not so severely flawed that it should have been completely ignored

Investigating Colors_CSTA_1995_San Jose

This workshop will give you an idea of the historical-investigative approach to teaching science ... more This workshop will give you an idea of the historical-investigative approach to teaching science developed at the Bakken Library and Museum in Minneapolis, MN and described
in the book Rediscovering Optics by Nahum Kipnis. ln this approach, physical concepts are introduced in the process of their discovery, which includes repeating historical experiments and comparing their different interpretations. The purpose of
this workshop will be introducing the concept of color.
This concept will be introduced in the way it was done historically: by comparing experimental results with various theories. Only simple and inexpensive instruments
are involved, primarily color filters and occasionally prisms.

Establishing a New Scientiic Concept_Galvani & Animal Electricity_1986_Pittsburgh

$Research paper thumbnail of Historical Experiments on Diffraction of Light_1994_Anaheim$

Historical Experiments on Diffraction of Light_1994_Anaheim

UNAPPRECIATED DISCOVERIES: HOW TO DEAL WITH THEM

$Research paper thumbnail of Rediscovering Diffraction_1995_Spokane, WA$

Rediscovering Diffraction_1995_Spokane, WA

The narrow purpose of this workshop is to show how to teach diffraction of light so as to improve... more The narrow purpose of this workshop is to show how to
teach diffraction of light so as to improve students' understanding of this topic. The workshop is based on Chapter| 1 of my book 'Rediscovering Optics' . The more general goal is lo draw teachers' attention to the opportunities provided by a qualitative approach to teaching physics based on using the history of science and investigative experimentation.

High Technology on Government Order - Early Soviet Computers_1989_Hamburg-Munich_abstract

High Technology on Government Demand - The Case of Soviet Computers_1987

The Dispute on the Animal Electricity_1985_Berkeley, CA

The 'Discovery of Electron' & the Nature of Science_AAPT_1998_New Orleans_abstract

A few examples of historical discoveries can increase students' interest in physics. The discover... more A few examples of historical discoveries can increase students' interest in physics. The discovery of the electron, for instance, sheds a new light on the relations between theory and experiment and the role of precision.
According to the tradition, it was an experimental discovery made by J. J. Thomson in 1897 as a result of measuring the charge-to-mass ratio e/m for cathode rays. He found that these particles were about 1,000 times lighter than hydrogen atoms and supposed them to be components of all atoms. Actually, that was only a part of a long and complex story. The particular nature of electricity in electrolytes was well accepted before
1895, and theoreticians attempted to extend it to other media. The first idea of a small particle came from the Zeeman effect (1896), Becquerel extended it to radioactivity, and Lenard to photoelectricity. On the basis of very crude measurements these results were generalized in 1900 into the concept of a universal charged particle called "electron."

Theoretical Models in Teaching Physics_1996_Bratislava_abstract

The Reception of Fresnel's Principle of Interference by Paris Academy of Sciences (1816-1824)_1983

The competition between the emission and wave theories of light in the early nineteenth century h... more The competition between the emission and wave theories of light in the early nineteenth century has provided historians with a difficult problem to solve: why did Thomas Young fail to establish the wave theory of light, while Augustine Fresnel succeeded? The response of Paris academicians to Fresnel's principle provides a partial answer that the situation in Paris c. 1816 was more favorable to the new theory than that in London c. 1804. In particular, several academicians agreed to accept the principle of interference as a mathematical principle, although they rejected the wave theory of light.

X-RAYS and RADIOACTIVITY: a CASE of a TANDEM DISCOVERY_1997_Paris

1. Röntgen's discovery The discovery of invisible rays penetrating opaque bodies made by Wilhelm ... more 1. Röntgen's discovery The discovery of invisible rays penetrating opaque bodies made by Wilhelm Konrad Röntgen became known to public early in January 1896: some scientists received personal communications from Röntgen, while the majority learned about it from newspapers. While it was the penetrative power of X-rays, revealed by Röntgen's photographs, that struck the imagination of everyone, scientists found another amazing feature of the new phenomena. On the one hand, the X-rays behaved like light, producing sharp images on a photographic plate. On the other hand, these rays considerably differed from light, in particular, they could not be regularly reflected or refracted; and they showed no sign of either polarization or interference. Röntgen concluded that, despite their ability to produce fluorescence and chemical reactions and discharge electrified plates, the X-rays could not be transverse waves similar to ultraviolet light. Nor could they be cathode rays exiting the tube, because X-rays penetrated air much easier than cathode rays, and they did not deviate even in a strong magnetic field. Röntgen decided that the only reasonable choice open was that the X-rays are produced by longitudinal waves in the ether. 2. Waves or particles? While some physicists agreed with Röntgen, a number of other hypotheses came to life, of which I'll briefly review only transverse waves and particles, as the most relevant for this paper. Several physicists, including Arthur Schuster, Goldhammer, George Fitzgerald, tried rehabilitating the hypothesis of transverse waves refuted by Röntgen. The idea was to assume that the wavelength of X-rays is comparable with the size of molecules. Such waves could travel in the substance with the same speed as in vacuum, without any noticeable refraction. Also, according to Fresnel's theory of diffraction, for extremely small wavelengths diffraction effects become insignificant. Experimenters found, however, great technical difficulties in measuring the wavelength of X-rays either from refraction or from diffraction. A very low intensity of diffracted rays required a long exposure, and quite often it was not clear whether an image broadening was due to diffraction or to overdevelopment of a photographic plate. Another problem was lack of homogeneity of X-rays. As the result, the wavelengths obtained varied widely (from 10 Å to 8300 Å) which of course provided no proof of the wave nature of X-rays. The first wavelengths of X-rays that were in the correct range (about 1Å) were obtained by Haga and Wind (in Holland) in 1899-1902 using diffraction on a narrow slit. The situation with polarization was no better than with interference or diffraction. The early positive results of Galitzine and Karnojitsky were never confirmed. The absorption of X-rays by two overlapping crystals did not depend on the mutual orientation of their optical axes, nor did a single crystal change its absorption when its axis made different angles with the beam of X-rays. Attempts to use fluorescence or diffraction grating to uncover polarization of X-rays also failed. The first positive (albeit indirect) signs of polarization of X-rays were obtained by Charles

X-rays & Radioactivity-the Case of a Tandem Discovery_Reno_1996

Thomas Young and the Discovery of the Principle of Interference of Light_1985

Thomas Young and the Concept of Coherence of Light

Two fundamental alternative theories of light were developed in the 17 th century: the emission o... more Two fundamental alternative theories of light were developed in the 17 th century: the emission or corpuscular theory and the wave theory. During the 18 th century the emission theory came to dominate over the wave theory, particularly in Britain and France. However, at the very beginning of the 19 th century Thomas Young attempted to revive the wave theory of light in the article " The Theory of Light and Colors " by adding a new significant concept, the principle of interference. According to this principle, when two waves meet at some point being in the same phase, their amplitudes add up and the intensity of light reaches its maximum, while if they are in the opposite phases their amplitudes subtract, and the intensity of light is minimal. Though any two intersecting waves disturb one another's motion, we can recognize this distortion only in some cases. In these cases I will call the phenomenon " interference " and the interfering waves, " coherent " waves. Young claimed that his principle of interference could account for all phenomena of the so-called " periodical colors " : Newton's rings, fringes surrounding shadows of bodies, halos around the Sun and the Moon, and so on. Before Young, some of these phenomena had been explained in the emission theory of light. [I would stress here that the term " interference phenomena " became meaningful only after the establishment of the principle of interference, thus it makes no sense to apply it to works of Robert Hooke and Isaac Newton as some scholars do.] Although Young's claim was basically correct, his principle was not adopted. Fifteen years later, Augustin Fresnel rediscovered the principle of interference and successfully applied it to the theory of diffraction of light. From that point on, this principle began to win recognition and acceptance. Explaining Young's failure to establish the principle of interference and the wave theory of light has been a persistent problem in the history of optics. Two distinct answers have been offered. According to the older view originated by François Arago, William Whewell, and George Peacock, Young's theory and the principle of interference were presented well, and the failure of its acceptance was due to external causes. Among them were Newton's authority as a staunch opponent of the wave theory, Henry Brougham' severe criticism, and the obscurity of Young's style. In a more recent view, Young's theory deserved its fate because of its many flaws, including many gratuitous assumptions, an insufficient experimental support, and his neglect of advanced mathematics. Kenneth Latchford and John Worrall claim that Young's principle of interference was nothing more than the well known mechanical principle of superposition, merely applied to optics. Worrall insists that Young had no clear idea of coherence, while Latchford's history of the principle of interference does not include this concept at all.

Physicists' Response to the Challenge of X-rays

The quest for establishing the nature of X rays ended in 1922 with Arthur Compton's explanation o... more The quest for establishing the nature of X rays ended in 1922 with Arthur Compton's explanation of the wavelength change in X-ray scattering, and its last decade was discussed in detail by Roger Stuewer. Here I am going to talk about the earlier period ending in 1912 with the discovery of diffraction of X rays by Laue, Friedrich and Knipping. My main focus will be on the first two years after Roentgen's discovery. That was the "heroic" period, when the nature of X rays was of a primary concern. It lasted long enough for all competing theories to emerge
and for physicists to realize that the direct attack on the problem had failed, and that the solution is not at all close.

Are old theories “rejected” or “abandoned”?

To describe the process by which an old scientific theory yields to a new one historians and phil... more To describe the process by which an old scientific theory yields to a new one historians and philosophers of science usually use such words as ‘refutation’ and ‘rejection’. In particular, there is
an opinion that a theory is “rejected” after being found ‘refuted’. It is not always clear, however, when these terms refer to actual contemporary views and when to scholars’ interpretations of the contemporary reaction. When a theory A is replaced by a theory B, before asking why did it happen it makes sense to ask what actually happened. In other words, what did this replacement consist of? Was the old theory completely forgotten, or was it deliberately rejected? And if it was
rejected, was it because it had been ‘refuted’?
An evaluation of this process depends on evaluators, be they researchers in the field, other scientists, teachers or textbook writers, and general educated public. In this paper, I will focus on researchers’ views.