#physic # [[Epistemic status]] #shower-thought #to-digest # Related - [[Constructor theory]] - [[Entropy, energy, assembly]] - [[Thermodynamics]] - [[Assembly theory]] - [[Second law of thermodynamics]] - [[Counterfactual]] - [[Physic/Constructor theory]] - [[Computing/Quantum/Universal quantum computer]] - [[Physic/Physic]] - [[Readwise/Articles/Operating System - Von Neumann Universal Constructor - Wikipedia]] # TODO > [!TODO] TODO # Universal constructor >The conservation of energy as a counterfactual principle about impossibility; three different kinds of irreversibility in physics—statistical, forgetful, and counterfactual; where I provide a counterfactual second law, based on an exact distinction between work and heat; and where you encounter the universal constructor, a machine that can perform all transformations that are physically possible >~ [[Chiara Marletto]] A Universal Constructor is a system capable of constructing any physical object, provided it has the instructions to do so and the necessary resources. This definition is significant because it brings together the concepts of information, [[Self replication|self-replication]] and universal computation, which are key concepts in the study of universal physical systems. By having a clear definition, researchers can now more easily discuss and study the properties of such systems. [[David Deutsch]] says that humans are universal constructors,in that we are able to construct a vast array of physical objects by combining and rearranging matter in different ways. However, our ability to do this is limited by our physical capabilities and the resources we have available to us. A true Universal Constructor would be capable of constructing any physical object, regardless of its complexity or the resources available. The concept of a Universal Constructor has far-reaching implications in various fields, including physics, computing, and biology. In physics, it is closely related to the ideas of Constructor theory and the Second Law of Thermodynamics. In computing, it is linked to the concept of a Universal Turing Machine, which is capable of simulating any other Turing Machine and therefore any computable function. Overall, the study of Universal Constructors and their properties is an important area of research that has the potential to shed light on fundamental questions about the nature of physical systems and their ability to perform complex tasks.