Editing Pierre Curie (section)

== Research ==
[[File:Curie1895These.jpg|thumb|left|''Propriétés magnétiques des corps à diverses temperatures'' <br />(Curie's dissertation, 1895)]]
Before his famous doctoral studies on magnetism, he designed and perfected an extremely sensitive [[torsion balance]] for measuring magnetic coefficients. Variations on this equipment were commonly used by future workers in that area. Pierre Curie studied [[ferromagnetism]], [[paramagnetism]], and [[diamagnetism]] for his doctoral thesis, and discovered the effect of temperature on paramagnetism which is now known as [[Curie's law]]. The material constant in Curie's law is known as the [[Curie constant]]. He also discovered that ferromagnetic substances exhibited a [[critical temperature]] transition, above which the substances lost their ferromagnetic behavior. This is now known as the [[Curie temperature]]. The Curie temperature is used to study plate tectonics, treat hypothermia, measure caffeine, and to understand extraterrestrial magnetic fields.<ref name="auto">{{cite book
    | last1=Redniss
    | first1=Lauren
    | title=Radioactive
    | date=2011
    | publisher=HarperCollins
    | location=New York, New York
    | page=30
}}</ref> The [[Curie (unit)|Curie]] is a unit of measurement (3.7&nbsp;×&nbsp;10<sup>10</sup> decays per second or 37 [[becquerel|gigabecquerels]]) used to describe the intensity of a sample of radioactive material and was named after Marie and Pierre Curie by the Radiology Congress in 1910.<ref>{{Cite web|last=Technology|first=Missouri University of Science and|title=- Nuclear Engineering and Radiation Science|url=https://nuclear.mst.edu/department/radiation/|access-date=11 December 2020|website=Missouri S&T|language=en-US|archive-date=11 February 2021|archive-url=https://web.archive.org/web/20210211002653/https://nuclear.mst.edu/department/radiation/|url-status=dead}}</ref><ref>{{cite book |url=https://books.google.com/books?id=7fUrAAAAIAAJ&pg=RA5-PA93 |page=93 |title=Semiannual Report of the Atomic Energy Commission, Volume 9 |author=[[United States Atomic Energy Commission]] |year=1951}}</ref>

Pierre Curie formulated what is now known as the ''[[Curie Dissymmetry Principle]]'': a physical effect cannot have a dissymmetry absent from its efficient [[causality (physics)|cause]].<ref name="Castellani">{{cite journal|last1=Castellani|first1=Elena|last2=Ismael|first2=Jenann|title=Which Curie's Principle?|journal=Philosophy of Science|volume=83|issue=5|pages=1002–1013|date=16 June 2016|doi=10.1086/687933|url=http://www.jenanni.com/papers/WhichCurie'sPrinciple.pdf|access-date=8 July 2016|hdl=10150/625244|s2cid=55994850|archive-date=30 August 2020|archive-url=https://web.archive.org/web/20200830230429/https://www.jenanni.com/papers/WhichCurie'sPrinciple.pdf|url-status=live|hdl-access=free}}</ref><ref name="Berova">{{cite book|last1=Berova|first1=Nina|author-link1=Nina Berova|title=Circular dichroism : principles and applications|date=2000|publisher=Wiley-VCH|location=New York, NY|isbn=0-471-33003-5|pages=43–44|url=https://books.google.com/books?id=oaxYis4mtecC&pg=PA43|access-date=8 July 2016}}</ref> For example, a random mixture of sand in zero gravity has no [[dissymmetry]] (it is [[isotropic]]). Introduce a [[gravitational field]], and there is a dissymmetry because of the direction of the field. Then the sand grains can 'self-sort' with the density increasing with depth. But this new arrangement, with the directional arrangement of sand grains, actually reflects the dissymmetry of the gravitational field that causes the separation.
[[File:Pierre and Marie Curie.jpg|thumb|Pierre and [[Marie Curie]] in their laboratory]]
Curie worked with [[Marie Curie|his wife]] in isolating [[polonium]] and [[radium]]. They were the first to use the term "[[radioactivity]]", and were pioneers in its study. Their work, including Marie Curie's celebrated doctoral work, made use of a sensitive piezoelectric [[electrometer]] constructed by Pierre and his brother Jacques Curie.<ref name="Nobel prize">{{cite web|title=Marie and Pierre Curie and the Discovery of Polonium and Radium|url=https://www.nobelprize.org/prizes/themes/marie-and-pierre-curie-and-the-discovery-of-polonium-and-radium|website=Nobelprize.org|date=2014|access-date=7 June 2020|archive-date=11 August 2020|archive-url=https://web.archive.org/web/20200811080718/https://www.nobelprize.org/prizes/themes/marie-and-pierre-curie-and-the-discovery-of-polonium-and-radium/|url-status=live}}</ref> Pierre Curie's 26 December 1898 publication with his wife and M. G. Bémont<ref name="Paper">P. Curie, Mme. P. Curie, and M. G. Bémont,  ''Comptes Rendus de l'Académie des Sciences'', Paris, 1898 (26 December), vol. 127, pp. 1215–1217.</ref> for their discovery of radium and polonium was honored by a Citation for Chemical Breakthrough Award from the Division of History of Chemistry of the American Chemical Society presented to the [[ESPCI ParisTech]] (officially the École supérieure de physique et de Chimie industrielles de la Ville de Paris) in 2015.<ref name="Award">{{cite web|title=2015 Awardees|url=http://www.scs.illinois.edu/~mainzv/HIST/awards/CCB-2015_Awardees.php|website=American Chemical Society, Division of the History of Chemistry|publisher=University of Illinois at Urbana-Champaign School of Chemical Sciences|date=2015|access-date=1 July 2016|archive-date=21 June 2016|archive-url=https://web.archive.org/web/20160621153928/http://www.scs.illinois.edu/~mainzv/HIST/awards/CCB-2015_Awardees.php|url-status=live}}</ref><ref name="Breakthrough">{{cite web|title=Citation for Chemical Breakthrough Award|url=http://www.scs.illinois.edu/~mainzv/HIST/awards/Citations/2015-Curie%20&%20Curie%20plaque.pdf|website=American Chemical Society, Division of the History of Chemistry|publisher=University of Illinois at Urbana-Champaign School of Chemical Sciences|date=2015|access-date=1 July 2016|archive-date=19 September 2016|archive-url=https://web.archive.org/web/20160919184204/http://www.scs.illinois.edu/~mainzv/HIST/awards/Citations/2015-Curie%20%26%20Curie%20plaque.pdf|url-status=live}}</ref> In 1903, to honor the Curies' work, the [[Royal society of london|Royal Society of London]] invited Pierre to present their research.<ref name=":0">{{Cite web|title=Marie Curie – Recognition and Disappointment (1903–1905)|url=https://history.aip.org/history/exhibits/curie/recdis1.htm|access-date=6 November 2020|website=history.aip.org|archive-date=11 February 2021|archive-url=https://web.archive.org/web/20210211002658/https://history.aip.org/history/exhibits/curie/recdis1.htm|url-status=live}}</ref> Marie Curie was not permitted to give the lecture so [[William Thomson, 1st Baron Kelvin|Lord Kelvin]] sat beside her while Pierre spoke on their research. After this, Lord Kelvin held a luncheon for Pierre.<ref name=":0" /> While in London, Pierre and Marie were awarded the Davy Medal of the Royal Society of London.<ref>{{Cite web|title=The Nobel Prize in Physics 1903|url=https://www.nobelprize.org/prizes/physics/1903/pierre-curie/biographical/|access-date=14 November 2020|website=NobelPrize.org|language=en-US|archive-date=4 July 2018|archive-url=https://web.archive.org/web/20180704124047/https://www.nobelprize.org/nobel_prizes/physics/laureates/1903/pierre-curie-bio.html|url-status=live}}</ref> In the same year, Pierre and Marie Curie, as well as Henri Becquerel, were awarded a Nobel Prize in physics for their research of radioactivity.<ref>{{Cite news|title=Pierre Curie|url=https://www.atomicheritage.org/profile/pierre-curie|access-date=14 November 2020|website=Atomic Heritage Foundation|language=en|archive-date=11 February 2021|archive-url=https://web.archive.org/web/20210211002629/https://www.atomicheritage.org/profile/pierre-curie|url-status=live}}</ref>

Curie and one of his students, Albert Laborde, made the first discovery of [[Nuclear binding energy|nuclear energy]], by identifying the continuous emission of heat from radium particles.<ref name="Abbott">{{cite journal|last1=Abbott|first1=Steve|last2=Jensen|first2=Carsten|last3=Aaserud|first3=Finn|last4=Kragh|first4=Helge|last5=Rudinger|first5=Erik|last6=Stuewer|first6=Roger H.|title=Controversy and Consensus: Nuclear Beta Decay 1911–1934|journal=The Mathematical Gazette|date=July 2000|volume=84|issue=500|pages=382|doi=10.2307/3621743|url=https://books.google.com/books?id=9TygBQAAQBAJ&pg=PA129|jstor=3621743|isbn=978-3-0348-8444-0}}</ref> Curie also investigated the radiation emissions of radioactive substances, and through the use of magnetic fields was able to show that some of the emissions were positively charged, some were negative and some were neutral. These correspond to [[alpha particle|alpha]], [[beta particle|beta]] and [[gamma radiation]].<ref name="Lagowski">{{cite book|last1=Lagowski|first1=Joseph J.|title=Macmillan encyclopedia of chemistry|date=1997|publisher=Macmillan Reference USA|location=New York|isbn=0-02-897225-2|page=1293|volume=2}}</ref>

=== Spiritualism ===
In the late nineteenth century, Pierre Curie was investigating the mysteries of ordinary [[magnetism]] when he became aware of the [[Spiritualism (movement)|spiritualist]] experiments of other European scientists, such as [[Charles Richet]] and [[Camille Flammarion]]. Pierre Curie initially thought the systematic investigation into the paranormal could help with some unanswered questions about magnetism.<ref name=Hurwic>{{cite book|last1=Hurwic|first1=Anna|title=Pierre Curie, Translated by Lilananda Dasa and Joseph Cudnik|date=1995|publisher=Flammarion|location=Paris|isbn=9782082115629}}</ref>{{rp|65}} He wrote to Marie, then his fiancée:  "I must admit that those spiritual phenomena intensely interest me. I think they are questions that deal with physics."<ref name=Hurwic />{{rp|66}} Pierre Curie's notebooks from this period show he read many books on spiritualism.<ref name=Hurwic />{{rp|68}} He did not attend séances such as those of [[Eusapia Palladino]] in Paris in June 1905<ref name=Hurwic />{{rp|238}} as a mere spectator, and his goal certainly was not to communicate with spirits. He saw the séances as scientific experiments, tried to monitor different parameters, and took detailed notes of every observation.<ref name=Hurwic />{{rp|247}} Curie considered himself as [[atheism|atheist]].<ref>Warren Allen Smith (2000). Who's who in hell: a handbook and international directory for humanists, freethinkers, naturalists, rationalists, and non-theists. Barricade Books. p. 259. {{ISBN|9781569801581}}. Retrieved 4 February 2017. Curie, Pierre (1859–1906) A co-discoverer of radium, Pierre Curie was an atheist.</ref>