3 ms·

I think you're coming at this backwards: the field is the best representation of what's seen in electromagnetic/gravitation/etc phenomena and not the other way

I think you're coming at this backwards: the field is the best representation of what's seen in electromagnetic/gravitation/etc phenomena and not the other way around. The fields (and their associated physical laws) accurately reproduce basically everything we've observed out there in the world in their respective domains. So regardless of some nebulous philosophical "ground truth", these mathematical laws provide a useful to way to think about these behaviors and make predictions of the future (and because these law are formulated mathematically, in many cases there are multiple entirely equivalent ways to work with them). Analogies of these fields to less fundamental things (like fluids) are just that: analogies, and don't hold any fundamental meaning. The physics of (e.g.) electromagnetism is a thing in itself and requires new primitives to talk about -- there isn't necessarily some more familiar thing hiding underneath -- the gravitational field isn't a fluid or solid or gas, it is it's own thing.

drran 5y ago
Field is the best representation, but what thing it represents? We are not talking about an analogy. We are talking about representation. A physical thing X is represented in physics as a field (3D array, [x,y,z]) of values of Y, so, if we have a field of Y, what is the X? For example, height field represents the height of piles of rock and dirt about ocean average level, so, Y is height, and X is the rock. What is represented by EM field, by gravitational field, etc.? (Beware: non-native speaker).
- radioactivist 5y ago
  Two things: 1) The phenomena of electromagnetism and gravity are fundamental as far as we can tell -- there is no more familiar or more commonplace "thing" I can tell you that they are "made" of. In fact if you really pressed it, your concept of a "rock" or "water" as a solid, distinct object out in the world is probably better thought of as a manifestation of electromagnetic behavior. That's just the way the world seems to be. If you drill down into it, our best physical theories describe everything in terms of fields defined over space (including all matter, like quarks, electrons, etc). So if you've a got a philosophical problem with fields for gravity and electromagnetism you've actually got a philosophical problem with basically all of our modern understanding of physics. 2) Whether our mathematics represents something intrinsic to the world rather than just providing a description of what we observe is a philosophical question (it's "ontological") that has no bearing of how well that description works. So if you want to think of space being permeated by real fields like the electromagnetic and gravitational fields you're free to do so. It'll give a useful and extraordinary precise description of the bundle of phenomena we call electromagnetism and gravity. Conversely, if you want to think of these things as well built crutches that don't properly represent (some yet undiscovered) deeper reality, but nonetheless give a very accurate description of it -- you can do that to, it won't make any difference in the physics.
  - drran 5y ago
    1) The Universe is endless in all directions, time, and scale, so there is no unbreakable particle or field. Fundamental fields(math) are defined(math) as fundamental(math). It looks like I need to switch to OpenGL to explain my point. 3D fields in OpenGL are defined as fundamental for OpenGL, but they are not fundamental for Universe. Modern OpenGL can be used to make astonishing predictions, but, IMHO, studying of OpenGL will not make me better at physics. However, if I will learn chemistry, optics, geology, fluids, mechanics, etc., then I will be able to make OpenGL better. Modern math apparatus in physics does astonishing predictions, but it cannot explain the underlying mechanic. IMHO, the solution is to make physical models, instead of mathematical models, of quantum objects, and study them with our own eyes, because it's easy to bend spacetime in math or OpenGL, but impossible in real physical world, so it forces making of realistic physical models. 2) I generated few ideas: Maybe, a huge wave passed through our Visible Universe, and caused a pressure drop in the ideal fluid AKA Physical Vacuum, so bubbles are popped up, and they are merging now from subatomic particles and up to supermassive black holes. Maybe, we are embedded into a huge massive object, so gravitation and EM are caused by rotation of this object, so gravitational attraction slowers rotation. I don't know. But, "energy is stored in 3D array of values, because 3D arrays are defined as foundational for mathematical apparatus of physics" - WTF it means?

drran 5y ago

Field is the best representation, but what thing it represents? We are not talking about an analogy. We are talking about representation. A physical thing X is represented in physics as a field (3D array, [x,y,z]) of values of Y, so, if we have a field of Y, what is the X? For example, height field represents the height of piles of rock and dirt about ocean average level, so, Y is height, and X is the rock. What is represented by EM field, by gravitational field, etc.? (Beware: non-native speaker).

radioactivist 5y ago
Two things: 1) The phenomena of electromagnetism and gravity are fundamental as far as we can tell -- there is no more familiar or more commonplace "thing" I can tell you that they are "made" of. In fact if you really pressed it, your concept of a "rock" or "water" as a solid, distinct object out in the world is probably better thought of as a manifestation of electromagnetic behavior. That's just the way the world seems to be. If you drill down into it, our best physical theories describe everything in terms of fields defined over space (including all matter, like quarks, electrons, etc). So if you've a got a philosophical problem with fields for gravity and electromagnetism you've actually got a philosophical problem with basically all of our modern understanding of physics. 2) Whether our mathematics represents something intrinsic to the world rather than just providing a description of what we observe is a philosophical question (it's "ontological") that has no bearing of how well that description works. So if you want to think of space being permeated by real fields like the electromagnetic and gravitational fields you're free to do so. It'll give a useful and extraordinary precise description of the bundle of phenomena we call electromagnetism and gravity. Conversely, if you want to think of these things as well built crutches that don't properly represent (some yet undiscovered) deeper reality, but nonetheless give a very accurate description of it -- you can do that to, it won't make any difference in the physics.
- drran 5y ago
  1) The Universe is endless in all directions, time, and scale, so there is no unbreakable particle or field. Fundamental fields(math) are defined(math) as fundamental(math). It looks like I need to switch to OpenGL to explain my point. 3D fields in OpenGL are defined as fundamental for OpenGL, but they are not fundamental for Universe. Modern OpenGL can be used to make astonishing predictions, but, IMHO, studying of OpenGL will not make me better at physics. However, if I will learn chemistry, optics, geology, fluids, mechanics, etc., then I will be able to make OpenGL better. Modern math apparatus in physics does astonishing predictions, but it cannot explain the underlying mechanic. IMHO, the solution is to make physical models, instead of mathematical models, of quantum objects, and study them with our own eyes, because it's easy to bend spacetime in math or OpenGL, but impossible in real physical world, so it forces making of realistic physical models. 2) I generated few ideas: Maybe, a huge wave passed through our Visible Universe, and caused a pressure drop in the ideal fluid AKA Physical Vacuum, so bubbles are popped up, and they are merging now from subatomic particles and up to supermassive black holes. Maybe, we are embedded into a huge massive object, so gravitation and EM are caused by rotation of this object, so gravitational attraction slowers rotation. I don't know. But, "energy is stored in 3D array of values, because 3D arrays are defined as foundational for mathematical apparatus of physics" - WTF it means?