Editing Max Planck (section)

=== Einstein and the theory of relativity ===
<!-- Commented out: [[File:Max-Planck-und-Albert-Einstein.jpg|thumb|Max Planck presents [[Albert Einstein]] with the Max-Planck medal, Berlin 28 June 1929]] -->
{{Special relativity sidebar}}

In 1905, the three epochal papers by [[Albert Einstein]] were published in the journal ''[[Annalen der Physik]]''. Planck was among the few who immediately recognized the significance of the [[special theory of relativity]]. Thanks to his influence, this theory was soon widely accepted in Germany. Planck also contributed considerably to extend the special theory of relativity. For example, he recast the theory in terms of classical [[Action (physics)|action]].<ref>''Einstein and the Quantum'', A.Douglas Stone, Princeton University Press, Princeton and Oxford, chapter 9, ''Tripping the light heuristic'', 2013.</ref>

Einstein's hypothesis of light ''quanta'' ([[photons]]), based on [[Heinrich Hertz#Electromagnetic research|Heinrich Hertz's]] 1887 discovery (and further investigation by [[Philipp Lenard#Photoelectric investigations|Philipp Lenard]]) of the [[photoelectric effect]], was initially rejected by Planck. He was unwilling to discard completely [[James Clerk Maxwell|Maxwell]]'s theory of [[electrodynamics]]. "The theory of light would be thrown back not by decades, but by centuries, into the age when [[Christiaan Huygens]] dared to fight against the mighty emission theory of [[Isaac Newton]] ..."<ref>{{Cite book|title=Atoms and Photons and Quanta, Oh My!: Ask the physicist about atomic, nuclear, and quantum physics|last=Baker|first=F. Todd|publisher=Morgan & Claypool Publishers|year=2015|isbn=978-1-62705-940-4}}</ref>

In 1910, Einstein pointed out the anomalous behavior of [[specific heat]] at low temperatures as another example of a phenomenon which defies explanation by classical physics. Planck and [[Walther Nernst]], seeking to clarify the increasing number of contradictions, organized the First [[Solvay Conference]] (Brussels 1911). At this meeting Einstein was able to convince Planck.

Meanwhile, Planck had been appointed dean of Berlin University, whereby it was possible for him to call Einstein to Berlin and establish a new professorship for him (1914). Soon the two scientists became close friends and met frequently to play music together.