<a href="https://en.wikipedia.org/wiki/Quantum_mechanics" id="mwfQ" rel="mw:WikiLink" title="Quantum mechanics">Quantum mechanics</a>: <a href="https://en.wikipedia.org/wiki/Max_Planck" id="mwfg" rel="mw:WikiLink" title="Max Planck">Max Planck</a> presents a theoretical derivation of his <a href="https://en.wikipedia.org/wiki/Planck's_law" id="mwfw" rel="mw:WikiLink" title="Planck's law">black-body radiation law (quantum theory)</a> at the Physic Society in Berlin.<sup about="#mwt81" class="mw-ref reference" data-mw='{"name":"ref","attrs":{},"body":{"id":"mw-reference-text-cite_note-14"}}' id="cite_ref-14" rel="dc:references" typeof="mw:Extension/ref"><a href="./December_14#cite_note-14" id="mwgA" style="counter-reset: mw-Ref 14;"><span class="mw-reflink-text" id="mwgQ">[14]</span></a></sup>
<span class="mw-reference-text" id="mw-reference-text-cite_note-14"><cite about="#mwt78" class="citation book cs1" id="CITEREFLegrand1987">Legrand, Jacques (1987). <i id="mwB7o">Chronicle of the 20th Century</i>. Ecam Publication. p.<span id="mwB7s" typeof="mw:Entity"> </span>22. <a class="mw-redirect" href="./ISBN_(identifier)" id="mwB7w" rel="mw:WikiLink" title="ISBN (identifier)">ISBN</a><span id="mwB70" typeof="mw:Entity"> </span><a href="./Special:BookSources/0-942191-01-3" id="mwB74" rel="mw:WikiLink" title="Special:BookSources/0-942191-01-3"><bdi id="mwB78">0-942191-01-3</bdi></a>.</cite><span about="#mwt78" class="Z3988" id="mwB8A" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=Chronicle+of+the+20th+Century&amp;rft.pages=22&amp;rft.pub=Ecam+Publication&amp;rft.date=1987&amp;rft.isbn=0-942191-01-3&amp;rft.aulast=Legrand&amp;rft.aufirst=Jacques&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3ADecember+14"></span></span>