I believe in the grand idea of “unification” in physics. In the last 150 years physicists have been trying to unify the known forces of nature. It started with Maxwell’s efforts to unify the electric and magnetic forces. We now refer to it as the electromagnetic force.
Einstein tried to unify the electromagnetic force with the gravitational force but failed. The unification of the electromagnetic force with the “Weak Nuclear Force” was achieved in the 60’s and 70’s. The unified force is now known as the electroweak force.
There is a theory known as GUT that tries to unify the electroweak force with the “Strong Nuclear Force.” GUT has not been experimentally verified yet.
The “holy grail” in the unification effort is to achieve the unification of all known forces in the framework of a quantum gravity theory. There are heroic efforts towards that goal but the goal remains elusive.
Physicists say that fields are fundamental and particles are incidental. This conviction is expressed in many mathematical forms and in various terms but in essence all physicists are saying the same thing. Physicists are more and more convinced that fields are more fundamental than particles. Field theorists say that elementary particles are ripples on the fields. String/M theorists think that elementary particles are extremely tiny vibrating filaments or membranes. I think of elementary particles as various twisted threads of the primordial fabric.
All these seemingly unrelated approaches can actually be expressed as effective field theories. The concept of “field” is very useful. I am glad that all physicists agree on the usefulness of the field concept. What bothers me is that nobody is trying to unify the fields?
How many fields are there? Too many! “What is an electron? Electron is a ripple on the electron field? What is a muon? Muon is a ripple on the muon field? What is a gluon? It is a ripple on the “strong field.” What is a Higgs particle? It is a ripple on the Higgs field.” According to the Quantum Field Theory there are different fields corresponding to different particle types. This does not make sense to me.
It is inconceivable for me to think that electron and neutrino are ripples on two different fields. I think that electron and neutrino are essentially the same. The manifestation of the charge and mass in the electron is related to the closure of the “thread loop” (see Prometheus and Chronos for a brief discussion). There must be a “fundamental field.” I call it a “thread” which, conceptually, is somewhere between a “field” and a “string/filament.”
There is an effort towards UFT (unified field theory) but it is very tentative. Just to repeat for emphasis, in other more common “unified” theories of physics there are multiple fields. The goal of UFT is to explain everything in terms of a single fundamental field. This was Einstein’s dream.