Tuesday, December 29, 2015

Book review: “Seven brief lessons on physics” by Carlo Rovelli

Seven Brief Lessons on Physics
By Carlo Rovelli
Allen Lane (September 24, 2015)

Carlo Rovelli’s book is a collection of essays about the fundamental laws of physics as we presently know them, and the road that lies ahead. General Relativity, quantum mechanics, particle physics, cosmology, quantum gravity, the arrow of time, and consciousness, are the topics that he touches upon in this slim, pocket-sized, 79 pages collection.

Rovelli is one of the founders of the research program of Loop Quantum Gravity, an approach to understanding the quantum nature of space and time. His “Seven brief lessons on physics” are short on scientific detail, but excel in capturing the fascination of the subject and its relevance to understand our universe, our existence, and ourselves. In laying out the big questions driving physicists’ quest for a better understanding of nature Rovelli makes it clear how the, often abstract, contemporary research is intimately connected with the ancient desire to find our place in this world.

As a scientist, I would like to complain about numerous slight inaccuracies, but I forgive them since they are admittedly not essential to the message Rovelli is conveying, that is the value of knowledge for the sake of knowledge itself. The book is more a work of art and philosophy than of science, it’s the work of a public intellectual reaching out to the masses. I applaud Carlo for not dumbing down his writing, for not being afraid of using multi-syllable words and constructing nested sentences; it’s a pleasure to read. He seems to spend too much time on the beach playing with snail-shells though.

I might have recommended the book as a Christmas present for your relatives who never quite seem to understand why anyone would spend their life pondering the arrow of time, but I was too busy pondering the arrow of time to finish the book before Christmas.

I would recommend this book to anyone who wants to understand how fundamental questions in physics tie together with the mystery of our own existence, or maybe just wants a reminder of what got them into this field decades ago.

[Disclaimer: I got the book as gift from the author.]


  1. "He seems to spend too much time on the beach playing with snail-shells though."

    Is this a reference to the famous Newton quote? "I know not what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me."

    I think Rovelli is one of the more interesting pundits on the scene. I recently heard an interesting talk (though the emphasis was somewhat different from the abstract, including some stuff from this paper (dig the comments)). His paper with Bianchi should be read by more people.

  2. "I was too busy pondering the arrow of time to finish the book" Physics postulates reality is fundamentally mirror symmetric, plus corrections toward matter. Any differentiable symmetry of the action of a physical system has a corresponding conserved charge. Reality is fundamentally chiral, including racemic combinations, containing an absolutely discontinuous symmetry toward matter.

    The breaking of time reversal symmetry creates chirality.
    Phys. Rev. A 82, 043811 (2010), arxiv:1006.0762, doi:10.1103/PhysRevA.82.043811
    Chirality is a strong arrow of time. The Second Law is statistical.
    Nature 463 210 (2010), doi:10.1038/nature08680
    Phys. Rev. D 71 057501 (2005), arxiv:hep-ph/0501282, doi:10.1103/PhysRevD.71.057501
    Phys Rev Lett. 91(24) 247404 (2003), arxiv:cond-mat/0307056, doi:10.1103/PhysRevLett.91.247404
    Chem. Phys. Lett. 173(5-6) 485 (1990), doi:10.1016/0009-2614(90)87240-R

    Theory should also consider what is observed.

    A sold ball is racemic not achiral, re Ashtekar-Barbero-Immirzi formulation of GR and torsion.
    Phys.Rev. D 73 084016 (2006), arXiv:gr-qc/0601013, doi:10.1103/PhysRevD.73.084016
    Class. Quant. Grav. 24 (16) 4207 (2007), arXiv:0706.1899, doi:10.1088/0264-9381/24/16/014
    Phys. Rev. D 92, 124031 (2015), arxiv:1507.00851, doi:10.1103/PhysRevD.92.124031

  3. https://edge.org/conversation/carlo_rovelli-science-is-not-about-certainty-a-philosophy-of-physics

    I like his take on the role of phylosophy and his ability to self-reflect as a scientist, as he does in this interview. Not just a smart guy but also wise man.

  4. Just read the transcript; will watch the video later. Should be required reading/viewing for everyone.

    Nice to see that he also agrees that Thomas Kuhn got it wrong, big time.

  5. Thanks Philip. When he says "questioning the question", that's where he summarizes the perfect attitude for physicists to construct new paths for a.o. quantum gravity. I believe Lee Smolin said something alike when he says "are we asking the right questions". Rovelli remarks that the wrong questions often arise from unconscientiously letting assumptions sneak into you question, meaning we have to be more prudent with conclusions collected in the past, at least that is what I make of it. A new Seitgeist should invite new interpretations.

    A remark on the side: It is like Sherlock Holmes who doesn't give a damn about the ongoing police investigation. He starts from scratch and questions everything to filter towards a more accurate and unbiased picture. Yet simultaneously he zooms in on the smallest details of the available existing data, knowing that nothing is to be treated as a mere coincidence.
    As Einstein said : " I am not more intelligent than other people, I just look much longer and harder where others have stopped looking."

  6. Not having started my blog yet, my
    appearing in old-school paper publications, take longer. This
    review of the same book
    has just appeared.


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