Light, Electromagnetic waves and their physical existence [closed]

Question

Part 1: First of all, I wish to discuss my idea of electromagnetic fields. I have it this way that fields are simply Mathematical tools developed for analyzing the (forces and energy) associated with a system. I consider it would have been perfectly fine (but extremely difficult) if we had described the system directly using forces instead of fields (Probably we would have then be required to additionally define the idea of potential momentum accounting for the momentum in the field). If there is something wrong or missing here, please correct me.

The main question is below;

Consider an electromagnetic wave with a frequency in the visible region. This is what we call light. However, light does appear in different colors, making them a real physical thing!

So, are electromagnetic fields actually physical, as we clearly have a physically observable property of color attributed to them?

If yes, then I wish to know the flaw in my understanding of fields (which were just mathematical tools for me).

Or, in case the answer is no then I would like to know what is the thing which is giving color to this electromagnetic wave?

Answer 1

Physics doesn't deal with whether or not various sorts of things exist, e.g. Does energy exist? Do fields exist? It uses concepts (like energy and fields) to make predictions and to show how many phenomena can be linked together by relatively few ideas.

Answer 2

Physics does not claim to be absolutely true. Instead, it merely claims that it is describing nature. Hence, even if two models/theories are inconsistent with each another, both can still be called physics.

Regarding "your theory", I doubt that you are able to describe all the electromagnetic effects using only forces and energy. E.g. the energy is proportional to the intensity and hence to $|E|^2$. Hence, by just using energy you will have troubles to describe an interference effect.

Answer 3

We do know that fields have a physical effect: for example, they can accelerate charges, which is measurable. Moreover the Electric Field is defined in terms of force, which you acknowledge is real in your question: it is the force exerted by a point charge or a group of point charges on a unit positive test-charge at a certain distance away.

Answer 4

tl;dr– Something exists iff it's there. This includes things that'd be described in mathematical terms, iff they're actually there. For example, visible light that is(n't) visible when you look at does(n't) exist.

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In science, something:

• exists if it's there;

• doesn't exist if it's not there;

• is extraneous if there's no distinction between the two.

For example:

• Visible light can be verified to exist through observational confirmation, e.g. seeing it.

• Visible light can be verified to not exist through observational confirmation, e.g. looking but not seeing it.

• Visible light that can't be verified to exist nor not-exist is extraneous e.g. light that could only be seen by a magical unicorn (if we pretend that magical unicorns don't exist).

Doesn't matter if something's purely mathematical or not. Doesn't matter if you can touch it or not. If it's there, it exists; if it's not there, it doesn't.

• For example, the constant speed-of-light, $c ,$ exists because it can be measured and verified to be there. Sure it's a mathematical constant, and sure you can't touch it, but it exists.

• For example, the constant rate-at-which-cars-move, $c_{\text{car}} ,$ doesn't exist. You can verify this: try measuring how fast cars move, and you'll find that there's not a constant. This means that $c_{\text{car}}$ doesn't exist – because it's not there.

Yes, this does mean that existence is subjective and model-dependent.

Answer 5

I consider it would have been perfectly fine (but extremely difficult) if we had described the system directly using forces instead of fields

It was tried by Ampére in the first half of the $19^{th}$ century by calculating forces between wires and elements of wires. The Newton law for gravity and the Coloumb law for electrostatic paved the way for that approach. The magnetic force was caused by micro-currents inside the materials according to Ampére.

Eventually the notion that forces between wires were mediated by a magnetic field prevails. One of the advantages of the field theories is that there is no action at a distance, what was a problem even for Newton himself.

Answer 6

I’m of the opinion that several of the previous answers overstate the frivolity of this question. Of course, questions of “reality” are rather more philosophical than physical, but we may ask the question of whether we could formulate a theory of electromagnetism which de-emphasizes fields in favor of potentials ($\phi$ and $A$) and sources ($\rho$ and $J$). @ClaudioSaspinski points out that this general idea was one of the original approaches to electromagnetic theory, and the idea of formulating electrodynamics without Maxwell’s Equations has modern proponents.

I’ll just point out that there is an electromagnetic conception of potential momentum, and it’s the magnetic vector potential $A$ (I recognize that this could be controversial). So if you choose to believe that the electric and magnetic fields are mere mathematical tools, then you still have the concept of color (i.e. frequency) rooted in something else: $A$!

Answer 7

The electromagnetic wave has its frequency and this is its color. Human sensors such as the eyes cannot simply detect the all frequency spectrum and also eyes are sensitive to the amplitude level. Even a vacuum has its own frequency. If something has no frequency (energy) it does not exist. The fact that we are unable to register this frequency does not mean that it does not exist.

I consider it would have been perfectly fine (but extremely difficult) if we had described the system directly using forces instead of fields

Contrary to appearances, it is not that difficult. The trick is to see through the fog of emergence.

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

Thanks to quantum physics and probability, it was possible to design some experiments that gave insight into the structure of a proton.

However, after the conducted experiments, it turned out many times that we were wandering in the fog.

For example, until the structure of the proton was unknown, it was not possible to use classical physics and forces to determine the orbits, shells and positions of electrons in atoms.

https://www.researchgate.net/publication/340741231_The_Geometry_of_the_Proton_and_the_Tetryen_Shape

https://vixra.org/abs/1708.0146

Today you can see that the mathematics behind probability, the dictates and prohibitions of quantum mechanics was just mathematics, and has little to do with physics.

Of course, all this math has allowed the experiments that reveal the true nature of the proton to be accelerated, so it cannot be considered worthless - quite the contrary.

Sorry for My English.