If you change the way you look at things, the things you look at change. Wayne Dyer
What is the fundamental idea behind fields in physics? Why do they exist?
Answered by Chris Quinn on Quora
I always enjoy seeing and answering questions which, rather than being concerned about a very specific problem in a very specific domain (aka: do my homework for me), jump right to the heart of a phenomenon which is expressed in a large variety of physics phenomenon and from which one can learn a lot about the state of physics from the answer.
>> If you look at the various dimensions of the workplace and corporate real estate, you can see one of the sources of curiosity for me about this subject. David Mills
What is a field?
Let’s start by examining what, exactly, is a field theory. A field theory is, in essence, a physics theory in which all interactions occur by mediation in a field. As a familiar example, one could model the vertical movement of a bobber on a lake in terms of the item “bobber” interacting with the field “lake.” Consider dropping a rock into a lake in which a bobber is floating.
The rock and bobber both interact with the water “field” producing a traveling, self-interacting wave in the field. This wave eventually reaches the bobber, and causes it to move. In much the same way, in all field theories of note forces travel in waves of self-field interactions induced by perturbations on the field. Field theories today are defined as a set of rules producing a self-interacting field through which an interaction between particles can be modeled.
The most important takeaway from this discussion are that fields provide an alternative method of modeling interactions in the world, they are not a “thing” but a propagator of interactions, and they are exactly defined at all points in space. This will be important when space stops being constant later.
Newton’s original formulation of his laws of motion proposed that forces occur between objects instantaneously regardless of distance, and such forces occur without any intervening medium to transmit the force . . .
Up to this point, physics mostly could be expressed both in terms of newtons law’s, and in terms of a field formulation. Special Relativity began to change this. Special relativity proposed a number of mathematical rules which originate from the two postulates . . .
For those thirsty for knowledge, considering examining a good book about quantum field theory or classical mechanics for more.