A luminous guide to how the radical new science of counterfactuals can reveal that the scope of the universe is greater, and more beautiful, than we ever imagined
There is a vast class of things that science has so far almost entirely neglected. They are central to the understanding of physical reality both at an everyday level and at the level of the most fundamental phenomena in physics, yet have traditionally been assumed to be impossible to incorporate into fundamental scientific explanations. They are facts not about what is (the actual) but about what could be (counterfactuals).
According to physicist Chiara Marletto, laws about things being possible or impossible may generate an alternative way of providing explanations. This fascinating, far-reaching approach holds promise for revolutionizing the way fundamental physics is formulated and for providing essential tools to face existing technological challenges--from delivering the next generation of information-processing devices beyond the universal quantum computer to designing AIs. Each chapter in the book delineates how an existing vexed open problem in science can be solved by this radically different approach and it is augmented by short fictional stories that explicate the main point of the chapter. As Marletto demonstrates, contemplating what is possible can give us a more complete and hopeful picture of the physical world.
“Marletto's call to probe counterfactuals is novel and interesting . . . Replete with stories from classical Greek mythology and examples of ideas drawn from biology and physics, The Science of Can and Can't is worth delving into.” —Wall Street Journal
“[A] revolutionary recasting of physics . . . Marletto’s contributions to ‘constructor theory’ reconcile what we think of as physical laws with the open-ended possibilities thrown up by biology and information theory. It is a paradigm that, for all its rigor, re-enchants the world and enriches our place in it.” —New Scientist
“[A] cerebral yet intellectually satisfying journey with a simple description of the two kinds of counterfactuals in physics . . . Marletto’s style resembles a frank conversation with the reader. Sophisticated concepts in physics, like information and knowledge, are explained using clear analogies to everyday life.” —Booklist
“[A] lyrical yet complex debut . . . References to Greek mythology, Shakespeare, chess, and Legos add life to her survey . . . Marletto’s love of physics shines through . . . Those with an interest in physics will appreciate her passion and her provocative approach.” —Publishers Weekly
“[T[here’s plenty of food for thought for those interested in the processes of conceptual breakthrough [in The Science of Can and Can't].” —Kirkus Reviews
"Marletto has a clear, sharp and imaginative style of explaining science . . . [The Science of Can and Can't] will open the doors to a dazzling, deep set of new concepts and ideas that will change and affect deeply the way you look at the world. Let her story unfold. It will be an open-ended exploration of the endless possibilities that the laws of physics allow for." —David Deutsch, author of The Beginning of Infinity
“Hugely ambitious, Chiara Marletto is the herald for a revolutionary new direction for physics. This book is essential reading for anyone concerned with the future of physics.” —Lee Smolin, author of Life of the Cosmos
"I enjoyed this book very much, not least because of the freshness of its approach to a subject that can easily become hard for the non-scientific mind to grasp. The theory of ‘can and can’t’ is an intriguing way of describing problems that are not only scientific (it describes very well what a storyteller does, for instance), and Marletto’s account of some things I thought I more or less understood (the nature of digital information, for one) illuminated them from an angle that showed them more clearly than I’d seen them before.” —Philip Pullman
About the Author
This is a philosophy book, not a science book, and not a particularly good one
If you were looking for an in depth discussion about how the reevaluation of the hidden assumptions in physics theories has lead, or is leading to, important new insights or breakthroughs - stop right there. At best, the author presents some superficial examples, but nothing that demonstrates the value this approach. There are a large number of assertions about the importance of the method, and how it can be applied to "knowledge" writ large, but nowhere does the book truly dig into any of these claims. This is coupled with rambling anecdotes and fantasies about the importance of playing the contrarian and finding the hidden assumptions. I did finish the book, but came away uninspired to say the least.
A Must Read for Anyone Interested in Foundational Science
Quantum mechanics and general relativity, the last two foundational breakthroughs in science, are a century old. Since then we have made tons of progress in more applied science, such as learning to decode and manipulate DNA and RNA, but we have been in a rut when it comes to developing a deeper understanding of such fundamental phenomena as information and heat.In her amazing book Chiara Marletto takes us on a journey into understanding how the structure of most existing scientific theories, which are expressed as states of the world in combination with laws of motion, has contributed to this stalling of progress. As an alternative approach she introduces the reader to Constructor Theory, a fundamental rethinking based on making counterfactuals first class elements. Instead of states and laws of motion. Constructor Theory builds up from possible and impossible transformations (hence the title).What is highly unusual about this book is that it provides an introduction accessible to lay readers to a theory that is currently under active development. This is a bit akin to being able to look over the shoulder of someone like Bohr or Einstein while they were working on their breakthroughs.
Interesting, but more appetizer than a complete meal
Marletto's The Science of Can and Can't is about the necessity of considering counterfactuals when developing scientific explanations. What could or cannot happen is just as important as what actually happened when developing science in domains that have resisted explanation. Specifically, Marletto applies counterfactuals to explain information, knowledge, and thermodynamics.I was attracted to this book because I love the oeuvre of David Deutsch, with who Marletto collaborated to develop many of these ideas. The Beginning of Infinity is my most favorite book of all time. And I love and relish re-reading The Fabric of Reality. So naturally, my expectations were sky--albeit unfairly--high. The Science of Can and Can't is well-written and easy to read, and it's certainly more accessible than a Deutsch book.In terms of convincing me of the importance of counterfactuals, the book was a success. The arguments are strong and the book draws corollaries to the fallacy of reductionism. My main gripe with The Science of Can and Can't is the lack of depth when getting to the counterfactual-based theories of information, knowledge, and thermodynamics. The theories are in development, so it’s hard to appreciate them fully. In particular, the book culminates with a way to understand thermodynamics at a quantum level, but I felt this section could have lingered there a bit longer. Okay, cool, we could potentially build nano-engines based on a counterfactual-based explanation, but how might that engine look and work? What will we use them for? The section seemed afraid to provoke the reader’s imagination and give some real-life possibilities.In sum, I would recommend The Science of Can and Can't with the view that it’s more about advocating the importance of counterfactuals than a retrospective of how counterfactuals have changed science. I hope the book wins more advocates; counterfactuals are worthwhile. And I look forward to learning more counterfactual-based explanations as they develop.
Possibility and progress
Was it possible and desirable for Charles Babbage to build his analytical engine back in the 1800s?Is it possible and desirable for everyone to speak Esperanto?The message of this book is that it is possible and desirable to translate all our physics theories into sets of statements about which classes of transformation are possible and which aren't.Well it might clean up our textbooks rather like Maxwell's Equations did but I doubt it will lead to any hoped-for progress. As I see it, progress depends upon appreciating and improving our understanding of what's already out there. This is because what's out there includes our existing hunches about what's out there and these reach slightly beyond existing formal theories, into the 'adjacent possible'. The path of progress lies in trying to elucidate these hunches.But if we try to make progress directly then we are at best building a shinier Star Trek set and at worst railing against reality.Contrast this with the amateur who doesn't try to specify in advance what criteria his new ideas shall meet. Following his intuition he is able to explore the limits of his knowledge and perhaps make a breakthrough which can be demonstrated to others.
A stunning dive into a different way to contemplate reality and knowledge. It feels like I’ve been given a different lens to view life through!
Very interesting read, easy to understand
Well written, clear and a really interesting new approach to thinking about physics.
Stimolante ma incompiuto
La parte migliore del libro sono le aggiunte alla fine dei capitoli nelle quali l'autrice dimostra di avere una buona capacità di costruire storie e scriverle bene. Stranamente, forse per modestia o timore di abbassare il livello scientifico del libro, l'autrice scrive che sono pagine che si possono saltare. Le pagine "vere" sono una lunga descrizione, chiara ma incompleta, di un paio di concetti che potevano essere condensati in pochi paragrafi. Ovviamente, il libro per essere letto e apprezzato richiede una conoscenza abbastanza approfondita dei principi base della fisica.
Disappointing and overblown
First, a scientist should not boast of her work as something that “can dramatically overhaul our current way of looking at the world”, a “mind-blowing step with the potential to unlock centuries-old secrets” (page XX): at best, it is bad behaviour, at worst it is snake-oil selling. Similar boasts can be found through the book, with frequent resort to the phrase “far reaching consequences” (variant: “sweeping consequences”).Second, words are important: Marletto defines a counterfactual as a fact “not about what is – the ‘actual’ – but about what could or could not be” (pag XV). This is NOT the standard definition of “counterfactual”, which is “something that is NOT the case, but could have been” (e.g. “something expressing what has not happened but could, would, or might under differing conditions” (Collins Dictionary).) Technical terms should be used for their meaning, without messing. Another example is the use of the word “knowledge”, defined (page 13) as “a particular kind of information, which has the capacity to perpetuate itself”. What’s the need for this extravagance?Third, in chapters 1 and 2 Marletto builds a strawman "traditional physics" easy to punch, described as if nothing were changed since the times of Laplace, with his omniscient demon. No physicist, reductionist as they may be, think of predicting the outcome of a football match on the basis of quantum fields equations: multi-level descriptions (explanation is a slippery word, which many avoid) are indeed standard.Fourth, and most important: Chapter 3 “Information” is messy at best, and it’s hard to make sense of. “Computation” is not a mere physical process, as “addition” is not the same as a physical adder; rather, addition may be performed by a physical adder, but addition existed before any physical adder was ever invented. This kind of confusion is blatant when discussing “universal computers” (page 91 ff), defined as computers “capable of performing all the computations permitted by the law of physics”. But what is the relationship between the set of “all the computations permitted by the laws of physics” and the set of computable functions, as defined by Computability Theory? Do time and resource constraints apply to this physicalist notion of computation? Nothing is said.Possibility and impossibility are not simple concepts. A perpetual motion machine and a round square are both impossible, but they’re impossible in different ways; and much more can be said. Marletto avoids any kind of complexity, and ends up with a book that is simplistic and tells no interesting story.