Quantum_ Einstein, Bohr and the Great Debate About the Nature of Reality - Manjit Kumar [187]
October: Heisenberg enrols to study physics at Munich University and meets fellow student Wolfgang Pauli.
1921
March: With Bohr as its founder and director, the Institute for Theoretical Physics in Copenhagen is officially opened.
April: Born arrives in Göttingen from Frankfurt as professor and director of the institute of theoretical physics, determined to make it the equal of Sommerfeld's institute in Munich.
October: After obtaining his doctorate from Munich University, Pauli becomes Born's assistant in Göttingen.
1922
April: Preferring city life to that in a small, provincial university town, Pauli leaves Göttingen to take up an assistant's position at Hamburg University.
June: Bohr gives a series of celebrated lectures in Göttingen on atomic theory and the periodic table. At this 'Bohr Festspiele', Heisenberg and Pauli meet the Dane for the first time. Bohr is deeply impressed by both young men.
October: Heisenberg begins a six-months' sojourn in Göttingen with Born. Pauli arrives in Copenhagen to be Bohr's assistant until September 1923.
November: Einstein is awarded the 1921 Nobel Prize and Bohr the prize for 1922.
1923
May: Arthur Compton's comprehensive report concerning his discovery of the scattering of X-ray photons by atomic electrons is published. The 'Compton effect', as it became known, is taken as irrefutable evidence in support of Einstein's 1905 light-quanta hypothesis.
July: Einstein's second visit to see Bohr in Copenhagen. Heisenberg just manages to obtain his doctorate from Munich University after poorly answering questions on experimental physics during his oral examination.
September: De Broglie links waves with electrons as he extends wave-particle duality to incorporate matter.
October: Heisenberg becomes Born's assistant in Göttingen. Pauli returns to Hamburg after a year-long stay in Copenhagen.
1924
February: Bohr, Hendrik Kramers and John Slater propose that in atomic processes energy is only conserved statistically, in an attempt to counter Einstein's light-quanta hypothesis. The BKS idea is experimentally disproved in April–May 1925.
March: Heisenberg pays his first visit to Bohr in Copenhagen.
September: Heisenberg leaves Göttingen to work at Bohr's institute until May 1925.
November: De Broglie successfully defends his doctoral thesis extending wave-particle duality to matter. Sent a copy of the thesis by de Broglie's supervisor, Einstein had earlier given it his nod of approval.
1925
January: Pauli discovers the exclusion principle.
June: Heisenberg goes to the small island of Helgoland in the North Sea to recover from a severe bout of hay fever. During his stay he takes the all-important first steps towards matrix mechanics, his version of the much sought-after theory of quantum mechanics.
September: Heisenberg's first ground-breaking paper on matrix mechanics, 'On a Quantum-Theoretical Reinterpretation of Kinematics and Mechanical Relations', is published in the Zeitschrift für Physik.
October: Samuel Goudsmit and George Uhlenbeck propose the concept of quantum spin.
November: Pauli applies matrix mechanics to the hydrogen atom. Averitable tour de force, it is published in March 1926.
December: While enjoying a secret rendezvous with a former lover in the Alpine ski resort of Arosa, Schrödinger constructs what will become his celebrated wave equation.
1926
January: Back in Zurich, Schrödinger applies his wave equation to the hydrogen atom and finds that it reproduces the series of energy levels of the Bohr-Sommerfeld hydrogen atom.
February: The three-man paper written by Heisenberg, Born and Pascual Jordan offering a detailed account of the mathematical structure of matrix mechanics is published after being submitted to the Zeitschrift für Physik in November 1925.
1926
March: Schrödinger's first paper on wave mechanics is published in the Annalen der Physik