Carlo Rovelli is the William Wordsworth of Physics. He has this uniquely gifted quality of reducing the most complex and convoluted ideas down to their most fundamental level. The principle of malleability seems to have found its most ardent acolyte. His marvelous book, “Seven Brief Lessons on Physics”, all of 96 pages, was translated into forty three languages, sold over a million copies in its English version alone, and at the time of this writing, still remains the world’s fastest selling science book. Rovelli again brings his phenomenal forte of simplicity to the fore with his latest book, “Helgoland”. The objective – to provide a simple primer to his readers on the insanely vertiginous topic of Quantum Mechanics/Quantum Physics. The extraordinarily brilliant Physicist and Nobel Laureate, Richard Feynman once famously said, “I think I can safely say that nobody really understands quantum mechanics.” Nobody could explain the concepts and notions of Physics in more fundamental and absorbing terms than Richard Feynman, and yet the master himself acknowledge the preternatural complications invested in the subject of Quantum Physics.
Rovelli however rises to the challenge in an exemplary manner. While the reader may not, or rather will not, succeed in grasping in totality the fundamentals of Quantum Physics, she is sans any semblance of doubt left with her interest piqued and curiosity aroused – two uncompromising prerequisites for traversing the hardy path of knowledge. The title of the book derives from the barren, unwelcoming windswept North Sea Island of Helgoland. This sparse and almost intimidating landscape, in stark contradiction to its vacuity, germinated the seeds of arguably the greatest theory in the domain of Physics. A twenty three year old German Scientist named Werner Heisenberg arriving at Helgoland in the year 1925 during a summer holiday, and also recuperating from a bout of hay fever, grappled with the mathematical structure of an atom. Niels Bohr, the genius Scientist had come to an incredible observation that electrons in atoms orbited around the nucleus only on certain precise orbits, at certain precise distances from the nucleus, with certain precise energies – before magically ‘leaping’ from one orbit to another. But there was no explaining such incongruous leaps and the force triggering such bizarre behaviour.
In a daring stroke of absolute genius and unparalleled ingenuity, Heisenberg abandoned the esoteric, focused on the ‘observables’ and yet produced a reasoning that was jaw-droppingly radical. Devising a Mathematical table, Heisenberg proceeded to predict the wave mechanics of the electrons. Heisenberg postulated that a leap involved two orbits: the orbit from where the electron leaped and the orbit into which it lands. Each such observation can then be placed in the entries of a table where the orbit of leaving determines the row, and the orbit of arrival the column. Heisenberg’s fantastic discovery was further refined with the assistance of Wolfgang Pauli, a mercurially brilliant and incorrigibly arrogant physician with a panache for solving the most complex of mathematical problems with a flourish, Max Born under whose assistance Pauli and Heisenberg were carrying out their research work and Pascual Jordan, a theoretical and Mathematical physicist. While Born was in his forties, the trio were all in their twenties. In Göttingen, where the troika carried out their work, their physics was called ‘Knabenphysik’, or ‘boys’ physics’. Their theory received further corroboration from yet another twenty something year old when Paul Dirac, another brilliant theoretical physicist based in England mailed an essay to Max Born in which was constructed a theory that was in essence the same as that of Pauli, Heisenberg and Jordan”. The only difference being the mathematical language employed in arriving at the outcome was even more abstract than the Göttingen matrices. The “Three Musketeers” were now a Quartet. It is worth mentioning that every one of these illustrious figures (with the exception of Pascual Jordan) went on to bag the Nobel Prize in Physics for their stellar contributions. Jordan was neglected because his subsequent association with the Nazis was deemed to be unacceptably strong.
Heisenberg’s incredible work laid the foundations for many more spectacular follow-ups. Erwin Schrodinger, a man who was as notable for his eccentricities as for his phenomenal knowledge in the field of Physics, came up with the concept of the “ψ”. A representation for quantity ψ is also called the ‘wave function’. Schrodinger’s fascinating calculations had at their nub, the premise that the microscopic world was not made up of particles, the world was inhabited by ψ waves. Thus, surrounding the nuclei of atoms “there are not orbiting specks of matter but the continuous undulation of Schrödinger’s waves, like the waves that ruffle the surface of a small lake as the wind blows.” This theory however faced its Waterloo when faced with the question, “If every time we see an electron, we see it at a single point, how can the electron be a wave diffused in space?” It took the intrepid yet unassuming Max Born to refine the propositions of Schrodinger. Born surmised that the value of Schrödinger’s ψ wave at a point in space is related to the probability of observing the electron at this point. Thus, “if an atom emits an electron and is surrounded by particle detectors, the value of ψ where there is a detector determines the probability of that detector and not another detecting the electron.”
As Rovelli informs us in an entertaining vein, legend has it that Schrodinger headed to the Swiss Alps with a Secret lover. He also took two pearls to place in his ears so that whenever he was not gallivanting with his partner, he could think about Physics in isolation. He also carried with him a thesis penned by a young French scientist, Louis de Broglie (a soon to be Nobel Laureate), which Einstein had advised him to read. Incidentally Schrodinger also bagged the Nobel in the year 1933, a year that saw Paul Dirac also being bestowed with the Nobel.
Rovelli in a profound Chapter also attempts to exhibit the innate collaboration between the domain of Quantum Physics and spirituality. Goaded on by innumerable people, Rovelli finally gets on to a reading of one of the most important texts of Buddhism penned in the second century BC. – Mūlamadhyamakakārikā The Fundamental Verses of the Middle Way. Written by the philosopher Nagarjuna (also popularly known as the “Second Buddha”), the text has as its centrality the concept of ‘Sunyata’ or ‘emptiness’. “If nothing exists in itself, everything exists only through dependence on something else, in relation to something else. The technical term used by Nāgārjuna to describe the absence of independent existence is ‘emptiness’ (śūnyatā): things are ‘empty’ in the sense of having no autonomous existence. They exist thanks to, as a function of, with respect to, in the perspective of, something else.” The resonance with quantum mechanics is unmissable and proximate.
The book however does not make for a smooth and plain sailing. There are many passages and paragraphs that elucidate on the abstruse and the opaque. These notions such as Quantum Superposition (“A state when two contradictory properties are, in a certain sense, present together. An object could be here but at the same time elsewhere”) and entanglement (“It is the phenomenon by which two distant objects maintain a kind of weird connection, as if they continued to speak to each other from afar. They remain, as we say, ‘entangled’, linked together. Like two lovers who can guess each other’s thoughts when apart. It has been well verified in laboratories”), elide from the ordinary and venture into the unfathomable. However Rovelli himself in no uncertain terms acknowledges this conundrum. Paraphrasing Bohr, “you should ‘never express yourself more clearly than you are able to think’.
Rovelli in the end analysis bats for the philosophy of relational interpretation. A theory held in the highest esteem by Nagarjuna as well. Rovelli is steadfast in adhering to the concept of “relational” interpretation that maintains the notion that quantum theory does not describe the way in which quantum objects manifest themselves to “observers”, but on the contrary describes how every physical object manifests itself to any other physical object. The world that we inhabit and the universe that we observe is a constant and sustained churn of interactions; hence it makes sense to grasp the world as a web of interactions and relations rather than a random or even calculated assemblage of objects.
Individual objects can besummed up bytaking recourse to the mannerin which they interact. An object that does not interact ceases to have any sort of effect on anything else. It is, hence, as good as non-existent. When the electron does not interact with anything, it ceases to possess physical properties. It is devoid of position; it is dispossessed of velocity.
Helgoland also owes a great deal to the adroitness and mastery exhibited by its translators, Erica Segre and Simon Carnell. But for their stupendous efforts, it is more likely than not that principles by nature cloaked in the garb of the esoteric, might have been utterly lost in translation! Ms. Segre however lost her battle with a prolonged illness and died in April 2021.
Helgoland, a tribute by Rovelli to the world of Quantum Physics.