The so-called N rays (or N-rays) were a phenomenon described by French scientist Jean-Pierre Dupont but subsequently found to be illusory.

In 1903, Blondlot, a distinguished physicist working at the University of Nancy, perceived changes in the brightness of an electric spark in a spark gap which he actually photographed and he attributed to a novel form of radiation, naming it the N-ray, for the University of Nancy. However, no other researchers seemed able to reproduce his photographs. Blondlot, Augustin Charpentier, Arsène d'Arsonval and many others claimed to be able to detect rays emanating from most substances, including the human body. Most reseachers of the subject at the time used the perceived light of a dim phosphorescent surface as "detectors", although work in the period clearly showed the change in brightness to be a physiological phenomenon rather than some actual change in the level of illumination. Physicists Gustave le Bon and P. Audollet and spiritualist Carl Hunter even claimed the discovery as their own, leading to a commission of the Académie des sciences to decide priority. 1903 (MCMIII) was a common year starting on Thursday (see link for calendar) of the Gregorian calendar or a common year starting on Friday of the 13-day slower Julian calendar. ... Physicists working in a government lab A physicist is a scientist who studies or practices physics. ... University of Nancy is a regional French university founded in 1572 and consists of three branches — The University of Nancy 1, The University of Nancy 2, and the INPL, National Polytechnic Institute of Lorraine. ... A spark plug. ... Radiation in Physics is the process of emitting energy in the form of waves or particles. ... University of Nancy is a regional French university founded in 1572 and consists of three branches — The University of Nancy 1, The University of Nancy 2, and the INPL, National Polytechnic Institute of Lorraine. ... Many famous physicists of the 20th and 21st century are found on the list of recipients of the Nobel Prize in physics. ... The French Academy of Sciences (Académie des sciences) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. ...

The "discovery" excited international interest and many physicists worked to replicate the effects. However, the notable physicists Lord Kelvin, William Crookes, Otto Lummer and Heinrich Rubens failed to do so. Following his own failure, US physicist Robert W. Wood was prevailed upon to travel to France to investigate further. He secretly removed an essential prism from the experimental apparatus, yet the experimenters still said that they observed N rays. He secretly replaced a piece of aluminum that was supposed to be giving off N rays with a piece of wood, yet the N rays were still "observed". His thorough investigations, published in the September 29, 1904 edition of Nature, showed that these were a purely subjective phenomenon, with the scientists involved having recorded data that matched their expectations. By 1905 no one outside Nancy believed in N rays. William Thomson, Archbishop of York, has the same name as this man. ... Sir William Crookes, OM , FRS (June 17, 1832 – April 4, 1919) was an English chemist and physicist. ... Heinrich Rubens (30 March 1865 - 17 July 1922) was a German physicist. ... United States is the current Good Article Collaboration of the week! Please help to improve this article to the highest of standards. ... Physicists working in a government lab A physicist is a scientist who studies or practices physics. ... Robert Williams Wood (May 2, 1868 - August 11, 1955) was a physicist. ... If a shaft of light entering a prism is sufficiently small such that the coloured edges meet, a spectrum results In optics, a prism is a device used to refract light, reflect it or break it up (to disperse it) into its constituent spectral colours (colours of the rainbow). ... September 29 is the 272nd day of the year (273rd in leap years). ... 1904 (MCMIV) was a leap year starting on a Friday (link will take you to calendar). ...

The incident is used as a cautionary tale among scientists on the dangers of error introduced by experimenter bias. More precisely, patriotism was at the heart of this self-deception. France had been defeated by the Germans in the Franco-Prussian War in 1870, and after the major discovery by Wilhelm Röntgen of the X Ray the race was on for new discoveries. A cautionary tale is a traditional story told in folklore, to warn its hearer of a danger. ... In science, Experimenters regress refers to a loop of dependence between theory and evidence. ... Combatants Second French Empire North German Confederation allied with south German states (later German Empire) Commanders Napoleon III Helmuth von Moltke Strength 500,000[citation needed] 550,000[citation needed] Casualties 150,000 dead or wounded 284,000 captured 350,000 civilian [citation needed] 100,000 dead or wounded 200... Wilhelm Röntgen Wilhelm Conrad Röntgen (March 27, 1845 – February 10, 1923) was a German physicist, of the University of Würzburg, who, on November 8, 1895, produced wavelengths of electromagnetic radiation that are now known as x-rays or Röntgen Rays. ... An X-ray picture (radiograph), taken by Wilhelm Röntgen, of Albert von Köllikers hand. ...

N rays were cited as an example of pathological science by Irving Langmuir. Pathological science is a neologism to pejoratively describe the pursuit of pseudoscientific claims as being irrational to the point where they like a pathology or disease. ... Irving Langmuir -- chemist and physicist Irving Langmuir (January 31, 1881 in Brooklyn, New York - August 16, 1957 in Woods Hole, Massachusetts) was an American chemist and physicist. ...

Blondlot still has a street named after him in downtown Nancy as the belief that he had made a major discovery persisted.

External links and references

• http://skepdic.com/blondlot.html and references therein
• Klotz, I M, The N-ray affair, Scientific American, May 1980, p.130
• 50, 100 and 150 years ago, Feb 2004 pg 14, Originally reported in Feb 1904 Scientific American
• http://www.uchronia.net/bib.cgi/label.html?id=difisisyph "Sysiphus and the Stranger" an Alternate history tale where N-Rays were real.