Causal Fermian Systems: A Theory of Everything You've Never Heard Of
This article discusses the theory of causal fermian systems, a potential "theory of everything" developed by Felix Finster. The core idea is that everything in the universe can be explained by firmians, which are the fundamental particles of matter. This theory offers a unique perspective compared to more well-known approaches like string theory.
What is a Theory of Everything?
A theory of everything aims to describe all fundamental interactions and particles in the universe within a single, consistent framework. Many physicists believe this unified framework will also provide insights into dark matter and dark energy. Currently, physics relies on two main frameworks:
-
The Standard Model of Particle Physics: Explains the electromagnetic, strong nuclear, and weak nuclear forces.
-
General Relativity: Describes gravity.
A true theory of everything must successfully combine these frameworks, notably by providing a theory of quantum gravity. However, a quantum gravity theory alone doesn't guarantee it's a theory of everything, as it might not encompass the Standard Model. Examples of quantum gravity theories that aren't theories of everything include loop quantum gravity and asymptotically safe gravity.
The Standard Model: Firmians and Bzons
The Standard Model consists of two types of particles:
-
Firmians: These are particles like electrons and quarks. They possess mass and have a spin of 1/2.
-
Bzons: These particles mediate the forces between the firmians. Examples include the photon (electromagnetic force), the gluon (strong nuclear force), and the W and Z bzons (weak nuclear force).
A key feature of the Standard Model is that the bzons arise from the properties of the firmians. The existence of conserved charges, such as electric charge, color charge, and weak hypercharge, necessitates symmetries. These symmetries, in turn, require the presence of the bzons.
Causal Fermian Systems: An Alternative Approach
Felix Finster's causal fermian systems approach differs from conventional theories. Instead of starting with space and time, it begins solely with matter in the form of firmians. These firmians form a network where:
-
Nodes represent the presence or absence of a firmian.
-
Links represent causal relations between the firmians.
Finster starts with the firmians already known from the Standard Model. The theory then demonstrates the emergence of:
-
Bzons.
-
Gravity. This emergence of gravity is the crucial aspect that positions it as a potential theory of everything.
The theory suggests gravity is inherently contained within the causal relations between the firmians. For these relations to be consistent, a universal interaction must couple to all energies and masses while conserving them. Gravity naturally fulfills this requirement and provides a way to organize the fermian network into an approximation of spacetime. In this view, spacetime is simply a way to describe how firmians interact.
Limitations and Potential
Currently, causal fermian systems have a limitation: it only recovers gravity in the weak field limit and does not yet fully derive Einstein's equations. However, it is believed that the full equations can be obtained by completing the weak field approximation.
The core idea that gravity is inherent in the causal structure also appears in other approaches, such as Stephen Wolfram's hypergraph model. This convergence suggests there might be fundamental truth to the concept that space and time are not fundamental entities, but rather emergent properties of a relational network.
Call to Action
This theory might not be the ultimate solution, but the approach is interesting and the speaker hopes it deserves more attention. If interested in this theory or any theory of everything, the speaker recommends checking out physics and math courses on Brilliant.
{#