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## Main Question or Discussion Point

Wikipedia:

The theory of

It seems possible this might be progress. A step toward a ‘theory of everything’….On the other hand, these guys might be waaaaay out there as I saw there were only three citations.

What do you think? I did not find discussions in these forums. I really like the concept that spacetime and particles and forces within emerge from a unified framework. They are not such distinct entities as we currently portray them.

Here is a quick summary of the theory:

https://en.wikipedia.org/wiki/Causal_fermion_system

Instead of introducing physical objects on a preexisting space-time manifold, the general concept is to derive space-time as well as all the objects therein as secondary objects from the structures of an underlying causal fermion system………..

Taking the concept seriously that the states of the Dirac sea form an integral part of the physical system, one finds that many structures (like the causal and metricstructures as well as the bosonic fields) can be recovered from the wave functions of the sea states. This leads to the idea that the wave functions of all occupied states (including the sea states) should be regarded as the basic physical objects…….

The physical picture is that one causal fermion system describes a space-time together with all structures and objects therein (like the causal and the metric structures, wave functions and quantum fields). In order to single out the physically admissible causal fermion systems, one must formulate physical equations. In analogy to theLagrangianformulation ofclassical field theory, the physical equations for causal fermion systems are formulated via a variational principle, the so-called

There is another description here:

http://arxiv.org/abs/1502.03587

“ The general structure of the theory of causal fermion systems can be understood in analogy to general relativity. In general relativity, our universe is described by a four-dimensional space-time (Lorentzian manifold) together with particles and fields.

However, not every configuration of Lorentzian metric, particles and fields is considered

to be “physical” in the sense that it could be realized in nature. Namely, for the configuration to be physically realizable, the Einstein equations must hold. Moreover, the particles must satisfy the equations of motion, and the additional fields must obey the field equations (like Maxwell’s equations). This means that in general relativity, there are two conceptual parts: on the one hand one has mathematical objects describing possible configurations, and on the other hand there is a principle which singles out the physical configurations………"

[The video link at the end of the Wikipedia article gets very mathematical within just two or three minutes and I could not understand the dialogue with the German accent.]

The theory of

**causal fermion systems**is an approach to describe fundamental physics. It gives quantum mechanics,general relativity and quantum field theory as limiting cases and is therefore a candidate for a unified physical theory.It seems possible this might be progress. A step toward a ‘theory of everything’….On the other hand, these guys might be waaaaay out there as I saw there were only three citations.

What do you think? I did not find discussions in these forums. I really like the concept that spacetime and particles and forces within emerge from a unified framework. They are not such distinct entities as we currently portray them.

Here is a quick summary of the theory:

https://en.wikipedia.org/wiki/Causal_fermion_system

Instead of introducing physical objects on a preexisting space-time manifold, the general concept is to derive space-time as well as all the objects therein as secondary objects from the structures of an underlying causal fermion system………..

Taking the concept seriously that the states of the Dirac sea form an integral part of the physical system, one finds that many structures (like the causal and metricstructures as well as the bosonic fields) can be recovered from the wave functions of the sea states. This leads to the idea that the wave functions of all occupied states (including the sea states) should be regarded as the basic physical objects…….

The physical picture is that one causal fermion system describes a space-time together with all structures and objects therein (like the causal and the metric structures, wave functions and quantum fields). In order to single out the physically admissible causal fermion systems, one must formulate physical equations. In analogy to theLagrangianformulation ofclassical field theory, the physical equations for causal fermion systems are formulated via a variational principle, the so-called

*causal action principle*. Since one works with different basic objects, the causal action principle has a novel mathematical structure where one minimizes a positive action under variations of the universal measure.There is another description here:

http://arxiv.org/abs/1502.03587

“ The general structure of the theory of causal fermion systems can be understood in analogy to general relativity. In general relativity, our universe is described by a four-dimensional space-time (Lorentzian manifold) together with particles and fields.

However, not every configuration of Lorentzian metric, particles and fields is considered

to be “physical” in the sense that it could be realized in nature. Namely, for the configuration to be physically realizable, the Einstein equations must hold. Moreover, the particles must satisfy the equations of motion, and the additional fields must obey the field equations (like Maxwell’s equations). This means that in general relativity, there are two conceptual parts: on the one hand one has mathematical objects describing possible configurations, and on the other hand there is a principle which singles out the physical configurations………"

[The video link at the end of the Wikipedia article gets very mathematical within just two or three minutes and I could not understand the dialogue with the German accent.]