Editing Matter wave (section)

==== Electrons ====
{{Further|Davisson–Germer experiment|Electron diffraction}}
In 1927 at Bell Labs, [[Clinton Davisson]] and [[Lester Germer]] [[Davisson–Germer experiment|fired]] slow-moving [[electron]]s at a [[crystal]]line [[nickel]] target.<ref name="DG1" /><ref name="DG2" /> The diffracted electron intensity was measured, and was determined to have a similar angular dependence to [[diffraction|diffraction patterns]] predicted by [[William Lawrence Bragg|Bragg]] for [[x-ray]]s. At the same time George Paget Thomson and Alexander Reid at the University of Aberdeen were independently firing electrons at thin celluloid foils and later metal films, observing rings which can be similarly interpreted.<ref name=GPTdiff/> (Alexander Reid, who was Thomson's graduate student, performed the first experiments but he died soon after in a motorcycle accident<ref>{{Cite journal |last=Navarro |first=Jaume |date=2010 |title=Electron diffraction chez Thomson: early responses to quantum physics in Britain |url=https://www.cambridge.org/core/product/identifier/S0007087410000026/type/journal_article |journal=The British Journal for the History of Science |language=en |volume=43 |issue=2 |pages=245–275 |doi=10.1017/S0007087410000026 |s2cid=171025814 |issn=0007-0874|url-access=subscription }}</ref> and is rarely mentioned.) Before the acceptance of the de Broglie hypothesis, diffraction was a property that was thought to be exhibited only by waves. Therefore, the presence of any [[diffraction]] effects by matter demonstrated the wave-like nature of matter.<ref>Mauro Dardo, ''Nobel Laureates and Twentieth-Century Physics'', Cambridge University Press 2004, pp. 156–157</ref> The matter wave interpretation was placed onto a solid foundation in 1928 by [[Hans Bethe]],<ref name="Bethe">{{Cite journal |last=Bethe |first=H. |date=1928 |title=Theorie der Beugung von Elektronen an Kristallen |url=https://onlinelibrary.wiley.com/doi/10.1002/andp.19283921704 |journal=Annalen der Physik |language=de |volume=392 |issue=17 |pages=55–129 |doi=10.1002/andp.19283921704|bibcode=1928AnP...392...55B |url-access=subscription }}</ref> who solved the [[Schrödinger equation]],<ref name="Schroedinger"/> showing how this could explain the experimental results. His approach is similar to what is used in modern [[electron diffraction]] approaches.<ref name="Cowley95">{{Cite book |last=John M. |first=Cowley |title=Diffraction physics |date=1995 |publisher=Elsevier |isbn=0-444-82218-6 |oclc=247191522}}</ref><ref name="Peng">{{Cite book |last1=Peng |first1=L.-M. |title=High energy electron diffraction and microscopy |date=2011 |publisher=Oxford University Press |first2=S. L.| last2=Dudarev | first3=M. J. |last3=Whelan |isbn=978-0-19-960224-7 |location=Oxford |oclc=656767858}}</ref>

This was a pivotal result in the development of [[quantum mechanics]]. Just as the [[photoelectric effect]] demonstrated the particle nature of light, these experiments showed the wave nature of matter.