Constructor theory

What if our current laws of physics are missing half the story because they only focus on what *does* happen, rather than what *could* happen? For centuries, from Isaac Newton to Albert Einstein, physics has been formulated in terms of "initial state plus laws of motion." We predict where a planet will be tomorrow by looking at where it is today and applying a formula. But this traditional approach struggles to explain things like life, information, and even thermodynamic heat. Enter **Constructor Theory**, a revolutionary new way of looking at the universe. ## The Physics of Can and Cannot Pioneered by physicist David Deutsch (a pioneer of quantum computing) and developed alongside researcher Chiara Marletto at the University of Oxford, Constructor Theory proposes a fundamental shift. Instead of describing the world in terms of trajectories and predictions, it describes the world in terms of **tasks**. A **constructor** is an entity that can cause a specific change in a physical system while remaining unchanged itself (like a automated factory machine, or a catalyst in a chemical reaction). In this framework, the fundamental laws of nature are expressed as statements about: 1. Which tasks are **possible** (and why). 2. Which tasks are **impossible** (and what prevents them). As Chiara Marletto explains in her book *The Science of Can and Can't*: > "Constructor theory expresses all laws of physics in terms of statements about what tasks are possible, what are impossible, and why... It allows us to bring things that were previously considered outside of physics—like information and life—into the domain of fundamental science." By focusing on what is possible, Constructor Theory provides a new mathematical language to explain concepts that traditional physics sweeps under the rug. For example, in classical physics, "information" is a vague, abstract concept. In Constructor Theory, information is defined robustly by whether a physical system can be copied from one medium to another. If a "copying task" is physically possible, then the system contains information. This theory could finally unite quantum mechanics and general relativity, not by finding a "particle of gravity," but by finding the common rules of what can and cannot be done to physical systems. ## To Learn More To dive deeper into this cutting-edge framework, you can explore: - The official [Constructor Theory Website](https://www.constructortheory.org/), which hosts research papers and introductory materials. - Chiara Marletto's popular science book, [*The Science of Can and Can't*](https://en.wikipedia.org/wiki/The_Science_of_Can_and_Can%27t), which explains these concepts without complex equations. ## Continue the Journey 1. If a constructor must remain unchanged after performing a task, can a perfect constructor actually exist in our universe, or are they only approximations? 2. How does redefining "information" through Constructor Theory help us build more resilient quantum computers? 3. If life is defined as a constructor that can maintain and replicate itself, how does this change our search for extraterrestrial life?