Editing Pathological science (section)

==Langmuir's examples==
[[Image:Blondlot N-rays.png|thumb|right|Fig. 6,7 from [[Prosper-René Blondlot]]: "Registration by Photography of the Action Produced by N Rays on a Small Electric Spark". Nancy, 1904.]]

===N-rays===
{{main|N ray}}

Langmuir's discussion of [[N ray|N-rays]] has led to their traditional characterization as an instance of pathological science.<ref>{{cite book |title= Constructivism in science education: a philosophical examination |chapter= Social constructivism, the Gospel of Science, and the Teaching of Physics |author-first= Helge |author-last=Kragh |author-link=Helge Kragh| editor-first= Michael R. |editor-last=Matthews |editor-link=Michael R. Matthews |edition= illustrated |publisher= [[Springer Science+Business Media|Springer Netherlands]] |year= 1998 |isbn= 978-0792350330 | page= 134 |url= https://books.google.com/books?id=iQtlWBBXKIoC }}</ref>

In 1903, [[Prosper-René Blondlot]] was working on [[X-ray]]s (as were other physicists of the era) and noticed a new visible radiation that could penetrate [[aluminium]]. He devised experiments in which a barely visible object was illuminated by these N-rays, and thus became "more visible". Blondlot claimed that N-rays were causing a small visual reaction, too small to be seen under normal illumination, but just visible when most normal light sources were removed and the target was just barely visible to begin with.

N-rays became the topic of some debate within the science community. After a time, American physicist [[Robert W. Wood]] decided to visit Blondlot's lab, which had moved on to the physical characterization of N-rays. An experiment passed the rays from a 2&nbsp;mm slit through an aluminum [[Prism (optics)|prism]], from which he was measuring the [[refractive index|index of refraction]] to a precision that required measurements accurate to within 0.01&nbsp;mm. Wood asked how it was possible that he could measure something to 0.01&nbsp;mm from a 2&nbsp;mm source, a physical impossibility in the propagation of any kind of wave. Blondlot replied, "That's one of the fascinating things about the N-rays. They don't follow the ordinary laws of science that you ordinarily think of." Wood then asked to see the experiments being run as usual, which took place in a room required to be very dark so the target was barely visible. Blondlot repeated his most recent experiments and got the same results—despite the fact that Wood had reached over and covertly sabotaged the N-ray apparatus by removing the prism.<ref name="Langmuir1953"/><ref name="Wood1904">{{Cite journal |last=Wood |first=R. W. |author-link=R. W. Wood |date=29 September 1904|title=The N-Rays |journal=[[Nature (journal)|Nature]] |volume=70 |issue=1822 |pages=530–531 |doi=10.1038/070530a0 |quote=After spending three hours or more in witnessing various experiments, I am not only unable to report a single observation which appeared to indicate the existence of the rays, but left with a very firm conviction that the few experimenters who have obtained positive results, have been in some way deluded. A somewhat detailed report of the experiments which were shown to me, together with my own observations, may be of interest to the many physicists who have spent days and weeks in fruitless efforts to repeat the remarkable experiments which have been described in the scientific journals of the past year.|bibcode = 1904Natur..70..530W |s2cid=4063030 |url=https://zenodo.org/record/1429443 }}</ref>

===Other examples===
Langmuir offered additional examples of what he regarded as pathological science in his original speech:<ref>{{cite web| url = http://www.cs.princeton.edu/~ken/Langmuir/langmuir.htm| title = transcript of speech}}</ref>
* The Davis–Barnes effect (1929; after Professor [[Bergen Davis]] from Columbia University)
* [[Mitogenetic rays]] (1923; [[Alexander Gurwitsch]] and others)<ref>For a review and bibliography, see Hollander and Claus, ''J. Opt. Soc. Am.'', 25, 270–286 (1935).</ref>
* The Allison effect (1927; after [[Fred Allison]]).<ref>{{cite journal |author1-first=F. |author1-last=Allison |author1-link=Fred Allison|author2-first=E. S. |title=A Magneto-Optical Method of Chemical Analysis |author2-last=Murphy |journal=[[Journal of the American Chemical Society]]|volume=52 |page=3796 |date=6 October 1930 |doi=10.1021/ja01373a005}}</ref> (b) <ref>{{cite journal |author1-first=F. |author1-last=Allison |journal=Industrial & Engineering Chemistry, 4, 9 |title=missing title|date=1932}}</ref>  (c) <ref>{{cite journal |author1-first=S. S. |author1-last=Cooper |author2-first=T. R. |author2-last=Ball |journal=[[Journal of Chemical Education]] |volume=13 |issue=5 |page=210 |date=1 May 1936 |doi=10.1021/ed013p210 |title=The magneto-optic method of chemical analysis. I. History and present status of the method}} </ref><ref>{{cite journal |author1-first=S. S. |author1-last=Cooper |author2-first=T. R. |author2-last=Ball |journal=[[Journal of Chemical Education]] |volume=13 |issue=6|date=1 June 1936 |doi=10.1021/ed013p278 |page=278 |title=The magneto-optic method of chemical analysis. II. Construction, adjustment, and operation of the apparatus; Physical measurements; Unknowns}}</ref><ref>{{cite journal |author1-first=S. S. |author1-last=Cooper |author2-first=T. R. |author2-last=Ball |journal=[[Journal of Chemical Education]] |volume=13 |issue=7 |page=326 |date=1 July 1936 |doi=10.1021/ed013p326|title=The magneto-optic method of chemical analysis. III. Location of minima and quantitative analysis}}</ref>(d) <ref>{{cite journal |author1-first=M. A. |author1-last=Jeppesen |author2-first=R. M. |author2-last=Bell |journal=[[Physical Review]] |publisher=[[American Physical Society]] |volume=47 |issue=7 |page=546 |doi=10.1103/PhysRev.47.546|title=An Objective Study of the Allison Magneto-Optic Method of Analysis|date=1 April 1935}}</ref> (e) <ref>{{cite journal |author1-first=H. F. |author1-last=Mildrum |author2-first=B. M. |author2-last=Schmidt |journal=Air Force Aero Propulsion Laboratory Technical Report |publisher=[[Defense Technical Information Center]]|url=https://apps.dtic.mil/sti/citations/tr/AD0634008|volume=66 |issue=52 |date=May 1966 |doi=10.21236/AD0634008|title=Allison Method of Chemical Analysis|url-access=subscription }}</ref><ref>{{citation |title= Finding francium |series= In Your Element |journal= [[Nature Chemistry]] |page= 670 |volume=1 |issue=8|date=1 November 2009 |url=https://www.nature.com/articles/nchem.430.pdf|doi=10.1038/nchem.430 |author-first= Eric |author-last=Scerri |author-link=Eric Scerri|pmid= 21378961 | quote= Dozens of papers were published on this effect, including a number of studies arguing  that it was spurious. These days the Allison effect is often featured in accounts of pathological science, alongside the claims for N-rays and cold fusion |bibcode= 2009NatCh...1..670S |doi-access= free }}
</ref>
* [[Extrasensory perception]] (1934), where [[Joseph Banks Rhine|Rhine]] consciously discarded contrary test results because he felt they could not be correct.

===Later examples===
A 1985 version{{Cn|date=October 2022}} of Langmuir's speech offered more examples, although at least one of these (polywater) occurred entirely after Langmuir's death in 1957:
* [[dowsing|Water dowsing]]
* [[Martian canals]] (Observed in late 19th century and early 20th century, they turned out to be optical illusions.)<ref>{{Cite book |title= Debating Psychic Experience: Human Potential Or Human Illusion? |last1=Krippner |first1=Stanley |author1-link=Stanley Krippner |first2=Harris L. |last2=Friedman |edition= illustrated |publisher= [[ABC-CLIO]] |year= 2010 |page= 151 |isbn= 978-0313392610 |url= https://books.google.com/books?id=F4-p5TIyoNMC | quote= Classic cases of pathological science, such as the alleged "discovery" of canals on Mars, N-rays, polywater, cold fusion, and so on are all testament to the fact that dozens of papers can appear in the scientific literature attesting to the reality of the phenomena, which turn out to be entirely illusory. }}</ref>
* Certain reported [[Photomechanical effect|photomechanical]] and [[Electromechanics|electromechanical]] effects {{Which|date=November 2010}}
* [[Polywater]]
* Biological effects of magnetic fields (see [[magnetobiology]] and [[magnet therapy]]) except [[Magnetoreception|magnetoception]]