B The relationship between the particle, the wave and the field

[geordief]

TL;DR Summary

Does the existence of a field imply the existence of the particle/wave or is it somehow the other way round?

What is it the we detect in the first instance?
Is it the particle |wave or is it the field?

Is the former more fundamental than the latter in any sense or are we just talking the opposite sides of the same coin?

For instance does the em field create the photon and the electron or could it be the other way round -or does such a "causal" relationship not exist.

 

[PeterDonis]

What is it the we detect in the first instance?
Is it the particle |wave or is it the field?

Is the former more fundamental than the latter in any sense or are we just talking the opposite sides of the same coin?

For instance does the em field create the photon and the electron or could it be the other way round -or does such a "causal" relationship not exist.

The answer to all of these questions is "mu".

"Particle", "wave", and "field" are not three different things with some kind of connection between them. They are different ways of describing the same thing. The usual technical term for that thing is "quantum field", but that does not change the fact that "particle" and "wave" are still just different words for it (or for particular configurations of it), not different things that are somehow connected to it.

 

[geordief]

So ,when a photon, as an example moves through space or spacetime is it in a sense moving through it's own medium -the em field?(the vacuum being the vessel of all the fields)

Since entanglement seems a more or less settled finding does that suggest that the Quantum field may support faster than light connections (not transfer of information,as I understand)?

(Have I gone off topic now?-it is a lot to take in.Is there a theory of how the various fields work together?)

 

[PeroK]

So ,when a photon, as an example moves through space or spacetime is it in a sense moving through it's own medium -the em field?(the vacuum being the vessel of all the fields)

In simple terms a photon is a perturbation in the EM field. That's one way we detect the EM field: by photon detection events; i.e. where the EM field interacts with the matter fields.

Since entanglement seems a more or less settled finding does that suggest that the Quantum field may support faster than light connections (not transfer of information,as I understand)?

No. There is a long, long thread on this here:

https://www.physicsforums.com/threa...n-professional-scientific-literature.1017491/

Is there a theory of how the various fields work together?)

That's provided by QFT. If a particle, such as the electron, has EM charge, then that means precisely that it is coupled to the EM field.

 

[vanhees71]

So ,when a photon, as an example moves through space or spacetime is it in a sense moving through it's own medium -the em field?(the vacuum being the vessel of all the fields)

Since entanglement seems a more or less settled finding does that suggest that the Quantum field may support faster than light connections (not transfer of information,as I understand)?

(Have I gone off topic now?-it is a lot to take in.Is there a theory of how the various fields work together?)

I'd rather say the electromagnetic field is an object that moves through space.

Relativistic QT must necessarily be formulated as quantum field theory precisely for the reason that only in terms of a local, i.e., microcausal quantum field theory it fulfills the demand of a causal theory, including the fact that there can be no causal connections between space-like separated events, which implies that there cannot be any signals transmitting information faster than allowed by the speed of light in a vacuum, which is the universal "limiting speed" of relativistic spacetime.

I'm not sure, what you mean by "how the various fields work together". The most comprehensive model about everything related to the matter we really know about is the standard model of elementary particles, which describes this matter as a relativistic local quantum field theory. According to this theory all the known matter is built from elementary particles called leptons and quarks. These interact via the strong and the electroweak forces, described as socalled gauge theories. For these forces you have vector fields and the corresponding "particles" called photons and W- and Z-bosons (electromagnetic and weak interactions between quarks and leptons) and gluons (mediating the strong interaction between quarks). Last but not least there's the Higgs field and its eponymous Higgs particle.

What is unknown is what the dark matter is made of, which is needed to understand astrophysical observations and the structure formation of the observed universe in cosmology.

The really fundamental enigma is, how to also describe the gravitational interaction within the framework of quantum theory.

 

[geordief]

I'd rather say the electromagnetic field is an object that moves through space

I feel like I am talking out of an abundance of ignorance but the em field never disappears does it?

Are you saying that it is the waves that move through the em field so that the em field increases and decreases in strength as one measures it at anyone point in space?

Like the cork bobbing in the water.The water (analogous to the field) doesn't move itself?

Or are you saying the the field (that I picture as a kind of ocean) is actually moving radially from the source of the wave?

Apologies if my question is getting confused or ,worse obtuse

 

[LCSphysicist]

I feel like I am talking out of an abundance of ignorance but the em field never disappears does it?

Are you saying that it is the waves that move through the em field so that the em field increases and decreases in strength as one measures it at anyone point in space?

Like the cork bobbing in the water.The water (analogous to the field) doesn't move itself?

Or are you saying the the field (that I picture as a kind of ocean) is actually moving radially from the source of the wave?

Apologies if my question is getting confused or ,worse obtuse

The Em field can not just disappear, since it would violate conservations law. But it can get attenuated as it propagates though a medium, like a plasma or a metal.

The wave moves through the medium, not through the em field. Of course the strength of the electric and magnetic field can depends on the point of space.

I think the main problem here is that you are confusing what is the medium, what are the waves and what is field and source. Electromagnetic waves are just electric+magnetic field propagating in the medium, as the name suggests. So the field (wave) can move radially away from the source, yes.

 

[vanhees71]

I feel like I am talking out of an abundance of ignorance but the em field never disappears does it?

No, why should it?

Are you saying that it is the waves that move through the em field so that the em field increases and decreases in strength as one measures it at anyone point in space?

The em. field is an object. It's presence can be measured by observing the motions of charged (test) particles.

Like the cork bobbing in the water.The water (analogous to the field) doesn't move itself?

Water as a continuum is described by fields (mass density, velocity, etc.) as well and it moves according to the "field equations" aka the hydrodynamic equations (e.g., the Euler equations of the perfect fluid or the Navier-Stokes equations for the viscous fluid, or the various relativistic fluid equations).

Or are you saying the the field (that I picture as a kind of ocean) is actually moving radially from the source of the wave?

Apologies if my question is getting confused or ,worse obtuse

Of course for a concrete physical situation you have to solve the field equations of motion. E.g., if you have a "point dipole source" you get something like a spherical wave around this source (of course with the correct dipole structure).

 

[geordief]

Thanks @vanhees71 , @LCSphysicist ., @PeterDonis and @PeroK
I will leave it for now and come back some time in the future when I may have learned a bit more of the basics