Mr. Babbage’s great calculating engine

What is constructor theory?

Constructor theory is a way of expressing all fundamental scientific theories using the idea of possible and impossible physical transformations. Those that can be made to happen and those that cannot. This is the deviation from the widespread conception of fundamental physics which works by predicting how the system is going to evolve starting from initial conditions and following specific laws of motion. But you might ask, why should we even try to challenge this traditional understanding of physics? Oftentimes, it may look like we unraveled all of nature’s little secrets, that we figured out all the formulas. But anyone within the scientific community would know that this is not the case. As a matter of fact, we still have a very long way to go despite all the progress physics made so far. Some problems that have been left unsolved for several decades now need attending to. This is why scientists have been working together and collaborating to try changing the tools that are used to address these problems.

What is the motivation behind this new theory?

Numerous subsequent motivations are discussed for expecting constructor theory to become one of the fundamental branches of physics. The theory’s potential for solving a myriad of problems and achieving unprecedented advancement in the unification of all laws of physics is being explored. Amongst them, we can site :

  • a theory of information concealed at the basis of both classical and quantum information;
  • extending the theory of computation to encompass all physical transformation;
  • combining formal statements of the laws of conservation with stronger operational ones (for example, because of the law of energy conservation we can exclude the possibility of existence of perpetual motion machines);
  • granting exact statements of emergent laws (like the second law of thermodynamics for instance);
  • and expressing in terms of physics certain attributes that are deemed anthropocentric or metaphysical (such as knowledge).

The difference between conventional physics and constructor theory

This is how physics usually functions:

  1. You start with what we see, with our experiences, with what exists in the world around us,
  2. Afterwards, physics attempts to come up with explanations, and it sort of explains that in terms of things that occur, either in the past or that will happen on the future.


They are things that are fundamental to our understanding of the world around us, both at the everyday level and at the level of the most important phenomena in physics, yet they have customarily been viewed as difficult to fuse into the fundamental scientific method and that have so far been neglected. They are facts, not with regards to what is (the “actual”), but rather concerning what physical event could or couldn’t be made to happen. In an effort to discern between them and the actual, they are called counterfactuals.

Prelude on Information

Something is able to hold information given that its state could have been different. Take a PC memory for example. It is absolutely useless if the factory foreordained every one of its changes and progressions in content over time, the client could not store anything in it. And this also applies if we were to replace “factory” with the Big Bang.

Information and Knowledge

There are two counterfactual properties that make a physical system capable of carrying information :

Universal Computer/Constructor



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Katia Demil

Katia Demil

Theoretical Physicist, tech enthusiast, lifelong learner!