Quantum_ Einstein, Bohr and the Great Debate About the Nature of Reality - Manjit Kumar [190]
November: Pauli is awarded the Nobel Prize for the discovery of the exclusion principle.
1946
July: Heisenberg is appointed director of the Kaiser Wilhelm Institute for Physics in Göttingen, later renamed the Max Planck Institute.
1947
October: Planck dies in Göttingen aged 89.
1948
February: Bohr arrives at the IAS as a visiting professor until June. Relations with Einstein are more cordial than during previous visits as both men continue to disagree over the interpretation of quantum mechanics. In Princeton, Bohr writes an account of the debate with Einstein at the Solvay conferences of 1927 and 1930 as his contribution to a volume of papers to celebrate Einstein's 70th birthday in March 1949.
1950
February: Bohr is at the IAS until May.
1951
February: David Bohm publishes his book Quantum Theory. It contains a novel and simplified version of the EPR thought experiment.
1952
January: Two papers by Bohm are published in which he does what von Neumann said was impossible: he offers a hidden variables interpretation of quantum mechanics.
1954
September: Bohr is at the IAS until December.
October: Bitterly disappointed at being overlooked when Heisenberg was honoured in 1932, Born is finally awarded the Nobel Prize for 'his fundamental work in quantum mechanics and especially for his statistical interpretation of the wave function'.
1955
April: Einstein dies in Princeton aged 76. After a simple ceremony, his ashes are scattered at an undisclosed location.
1957
July: Hugh Everett III puts forward the 'relative state' formulation of quantum mechanics, later known as the many worlds interpretation.
1958
December: Pauli dies in Zurich aged 58.
1961
January: Schrödinger dies in Vienna aged 73.
1962
November: Bohr dies in Copenhagen aged 77.
1964
November: John Bell's discovery that any hidden variables theory whose predictions agree with those of quantum mechanics must be non-local is published in a little-read journal. Known as Bell's inequality, it derives limits on the degree of correlation of the quantum spins of entangled pairs of particles that have to be satisfied by any local hidden variables theory.
1966
July: Bell shows conclusively that von Neumann's proof ruling out hidden variables theories, published in 1932 in his book The Mathematical Foundations of Quantum Mechanics, is flawed. Bell had submitted his paper to the journal Review of Modern Physics at the end of 1964, but an unfortunate series of mishaps delayed its publication.
1970
January: Born dies in Göttingen aged 87.
1972
April: John Clauser and Stuart Freedman at the University of California, Berkeley, having conducted the first test of Bell's inequality, report that it is violated – any local hidden variables cannot reproduce the predictions of quantum mechanics. However, there are doubts about the accuracy of their results.
1976
February: Heisenberg dies in Munich aged 75.
1982
After years of preliminary work, Alain Aspect and his collaborators at the Institut d'Optique Théoretique et Appliquée, Université Paris-Sud, subject Bell's inequality to the most rigorous test then possible. Their results show that the inequality is violated. Although certain loopholes remain to be closed, most physicists, including Bell, accept the results.
1984
October: Dirac dies in Tallahassee, Florida aged 82.
1987
March: De Broglie dies in France aged 94.
1997
December: A team at the University of Innsbruck led by Anton Zeilinger reports that it has succeeded in transferring the quantum state of a particle from one place to another – in effect, teleporting it. An integral part of the process is the phenomenon of quantum entanglement. A group at Rome University, under the leadership of Francesco DeMartini, also successfully carries out quantum teleportation.
2003
October: Anthony Leggett publishes a Bell-type inequality derived on the basis that reality is non-local.
2007
April: An Austrian-Polish team led by Markus Aspelmeyer and