With Constructor Theory, Chiara Marletto Invokes the Impossible | Quanta Magazine
“At the heart of constructor theory is the feeling that there’s something missing in our usual approach to physics.
The standard laws of physics — such as quantum theory, general relativity, even Newton’s laws — are formulated in terms of trajectories of objects and what happens to them given some initial conditions. But there are some phenomena in nature that you can’t quite capture in terms of trajectories — phenomena like the physics of life or the physics of information. To capture those, you need counterfactuals.
Which are?
The word “counterfactual” is used in various ways, but I mean a specific thing: A counterfactual is a statement about which transformations are possible and which are impossible in a physical system. A transformation is possible when you have a “constructor” that can perform a task and then retain the capacity to perform it again. In biology, we call that a catalyst, but more generally we can call it a constructor.”