Quantum mechanics and general relativity, the last two foundational breakthroughs in science, are a century old each. 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. I believe that this lack of a new fundamental breakthrough is contributor to an overall slowing down of scientific progress that has been widely noted.

In her wonderful book “The Science of Can and Can’t” Chiara Marletto takes us on a fascinating journey into the foundations of scientific theories. Newtonian (classical) mechanics, quantum mechanics and general relativity all share the same structure: a description of states of the world combined with laws of motion which govern how states evolve. This approach has proven incredibly powerful but also has important limits.

Chiara introduces an alternative approach called Constructor Theory, which she has been developing together with David Deutsch and a small team at Oxford. Instead of states and laws of motion. Constructor Theory builds upon the distinction between possible and impossible transformations (hence the title of the book). In doing so, Constructor Theory makes counterfactuals first class elements of science, i.e. statements about what could be or could have been, but maybe has not (yet) occurred.

The book does a terrific job explaining why this matters and what Constructor Theory is seeking to accomplish. Let me provide just a few hints. First, a precise theory of such phenomena as heat, which current theories approach statistically. Second, a unification of our understanding of classical and quantum information theories. Third, a theory of quantum computing that is abstracted from quantum mechanics (our theory of classical computation after all isn’t tied to classical mechanics or electric fields).

One of the many lovely illustrations from the book:

Quantum mechanics and general relativity, the last two foundational breakthroughs in science, are a century old each. 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. I believe that this lack of a new fundamental breakthrough is contributor to an overall slowing down of scientific progress that has been widely noted.

In her wonderful book “The Science of Can and Can’t” Chiara Marletto takes us on a fascinating journey into the foundations of scientific theories. Newtonian (classical) mechanics, quantum mechanics and general relativity all share the same structure: a description of states of the world combined with laws of motion which govern how states evolve. This approach has proven incredibly powerful but also has important limits.

Chiara introduces an alternative approach called Constructor Theory, which she has been developing together with David Deutsch and a small team at Oxford. Instead of states and laws of motion. Constructor Theory builds upon the distinction between possible and impossible transformations (hence the title of the book). In doing so, Constructor Theory makes counterfactuals first class elements of science, i.e. statements about what could be or could have been, but maybe has not (yet) occurred.

The book does a terrific job explaining why this matters and what Constructor Theory is seeking to accomplish. Let me provide just a few hints. First, a precise theory of such phenomena as heat, which current theories approach statistically. Second, a unification of our understanding of classical and quantum information theories. Third, a theory of quantum computing that is abstracted from quantum mechanics (our theory of classical computation after all isn’t tied to classical mechanics or electric fields).

One of the many lovely illustrations from the book: