Book Review: Helgoland by Carlo Rovelli
Helgoland is windswept and relatively barren island where Werner Heisenberg repaired to contemplate the puzzles of quantum phenomena, and, ultimately, to invent quantum mechanics. At this point quantum theory was already a quarter of a century old, invented by Max Planck in 1900 and further developed by Einstein, Bohr, and others but only very special and simple cases could be solved. A method of general application did not exist. After weeks of intense mental struggle he found an answer in the behavior of tables of numbers, tables that would become the matrices of matrix mechanics.
Carlo Rovelli, himself an important physicist, tells that
story in the first chapter of his book Helgoland, as well as the struggles of
Heisenberg and others to understand what he had found. In quick succession the English Physicist
Paul Dirac and the Austrian Erwin Schrodinger found apparently quite different
but completely equivalent formulations of quantum mechanics. All formulations turn out to present
fundamental challenges to our intuitions for understanding the world. Rovelli presents the essential feature of
quantum theory as follows:
“I have told the story of how
quantum theory was born between 1925 and 1926, and have introduced two ideas:
the peculiar idea, found by Heisenberg, of describing only observables, and the
fact that the theory predicts only probabilities, understood by Born.”
“Rovelli, Carlo. Helgoland (p. 30).
Penguin Publishing Group. Kindle Edition.”
It takes him a bit to get his third key idea, but it is granularity,
the property that puts the quantum in quantum theory, energy, angular
momentum and other things come only in discrete lumps.
So how can all this be understood? Rovelli outlines several popular
interpretations of quantum theory including the Many Worlds theory, hidden
variables, wave function collapse and so-called QBism, before turning to his
own favorite relational interpretation.
It is based on the idea that all things are defined only by their
relation to other things, and illustrated by homely examples and decorated by
classical allusions, but my first impression was a bit hostile. Yeah, yeah, I thought, but what has this to
do with quantum phenomena? It looks
pretty fluffy to me so far.
Unfortunately it just gets fluffier from there. Next our author wanders into philosophy,
starting with Ernst Mach, a physicist-philosopher who deeply influenced
Heisenberg and Einstein, and, he adds Marx and Engels, segueing into a debate
between Lenin and Alexander Bogdanov, a fellow revolutionary. He is impressed by Lenin’s philosophical
erudition but critical of his penetration.
I could say the same about Rovelli.
What does any of this have to do with physics or quantum
mechanics? As the cliché has it, “where
is the beef?” I’m afraid I never see it.
The rest of the book is long on philosophy, and short on
physics, and, for me, insight.
A promising start leading to a big disappointment.
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