Nature India | Indigenus

Quantum review

I just finished reading Manjit Kumar’s ‘Quantum’ effusively praised across the western world for its expert weaving of science and history. Here is my review of the book, written on invitation from a New Delhi-based daily, and reproduced below.

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Fitting epitaph to Einstein’s light box

No idea if the theory of relativity has a clause to explain this or it was sheer coincidence that while physicists across the world were flipping through ‘Quantum’, their peers from the Massachusetts Institute of Technology (MIT) revealed newer aspects of Max Planck’s famous 1900 experiment on non-reflective objects –- the blackbodies. Manjit Kumar’s book has a fair share of Planck but is widely hyped as the book on the spat between two other titans –- Neils Bohr and Albert Einstein.

For those who get excited over the grandeur and mystique of one of the most debated realities of physics –- the ‘Quantum theory’ –- the book cruises past the lives and works of many old masters and young turks -– Ernest Rutherford, Prince Louis De Broglie, Wolfgang Pauli, Erwin Schrodinger and Arnold Sommerfield, to name a few.

And for the uninitiated, there’s plenty of insight into the rigours of doing science in an era when the “search for the absolute was the loftiest of all scientific activity” — again a Planck quote. They threw theories to test themselves against hard experimental facts and went to great lengths to do so.

Sample this: Planck getting up in the middle of the night to post a note with the equation for the blackbody spectrum. Or this: Albert Einstein hurrying to work at the Swiss Patent Office in Bern in a plaid suit and a pair of worn out slippers with embroidered flowers in 1905. The same year saw the ‘patent slave’ publish four landmark papers, explaining the quantum, atom sizes, Brownian motion and relativity – transforming all physics in the years to come. He also found the time and energy that year to write 21 book reviews for the journal Annalen der Physik! A fifth paper, as an afterthought, had the all famous equation: E=mc2.

The comparison between Einstein and Bohr makes for interesting anecdotes. Like Einstein, Bohr the handsome Dane, did badly in the languages department at school but had an aptitude for maths and science. Unlike him, Bohr struggled to express himself in English. While on his honeymoon, Bohr wrote his paper on alpha particles dictating it to wife Margrethe as she corrected his English and put words to his random thoughts.

These brilliant nuggets take the book beyond an academic pursuit of the quantum atom, aptly described by Bohr as the triumph of mind over matter. And the liberal sprinkling of history –- the famous Solvay conference of 1930 (though putting the pictures and the vivid text side by side would have been a better idea) or the Nazi purge of German civil services when Planck met Hitler to ask him to spare the scientific community –- gives the right backdrop to the scientific drama unfolding in the 20th century.

The public play of the Einstein-Bohr conflict in The New York Times in 1935 is reassuring –- the more things change, the more they remain the same. The cheeky practice of advance publication of scientific announcements in the press is not new after all! The controversy began in the journal Nature when Bohr challenged Einstein over quantum mechanics with a promise by Bohr that a “fuller development of this argument will be given in an article to be published shortly in Physical Review.”

The book leaves the debate hanging –- towards the end of the ‘Quantum’ plot, Einstein dies at 112 Mercer Street, an address that goes on to become one of the most famous in the world, surrounded by portraits of Faraday, Maxwell and Gandhi. There he ‘hibernates’ till his death in 1937, which, incidentally, does not end the debate. In 1962, Bohr dies and the last drawing on the blackboard in his study replays the keenest of his arguments with Einstein –- that of Einstein’s celebrated light box.

Physicists across the world have not been able to avoid getting sucked into the quantum debate ever since, like Planck, who steered clear of the theory as much as he could but became the ‘reluctant revolutionary when he hinted about it first, “We have to live with the quantum theory," he said, “and believe me, it will expand.”