I like to think of gravity as displacement of the "ether ". I suppose negative mass would have a type of repelling effect on mass which I figure is energy of various negative mass.
Radio waves are relatively low in negative mass along with photons.
> I like to think of gravity as displacement of the "ether ".
You are only behind physics community by ~140 years [1]. We know for sure that there is no "ether" so its displacement is not what causes gravity. It was a trial to explain how light would move if it is wave, which we didn't know about EM waves then.
From MM experiment, we know for sure that there's no ether with the properties that were ascribed to it. However, you can easily come up with a theory of ether that completely matches those observations - it's just not as useful as a model because the concept itself becomes kinda redundant at that point. However, this is just as much an issue of terminology. Here's Einstein on the subject:
"More careful reflection teaches us however, that the special theory of relativity does not compel us to deny ether. We may assume the existence of an ether; only we must give up ascribing a definite state of motion to it, i.e. we must by abstraction take from it the last mechanical characteristic which Lorentz had still left it. We shall see later that this point of view, the conceivability of which I shall at once endeavor to make more intelligible by a somewhat halting comparison, is justified by the results of the general theory of relativity ... according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable."
I didn't think there was such a thing as negative mass. That is, you can hypothetically have gravity that is repulsive, but you cannot have negative mass because mass is a property of matter conveyed by the Higgs field. All matter has some positive value for mass; the measure of the matter's resistance to acceleration.
Photons (a.k.a energy, including radio waves) do not interact with the Higgs field and so have zero mass.
There is no negative Higgs field, and no negative mass.
There's also no ether either as originally constructed (it was ruled out by experiment) but you could be speaking metaphorically.
Photons have zero rest mass. But they're never at rest, they are always travelling at the speed of light. They have mass equivalent to their energy, which is related to their wavelength.
Mainstream academic physics has completely eliminated the concept of non-rest, variable mass. Mass and energy are equivalent, so you CAN apply mass values to the kinetic energy of a particle, but it turns out to be more confusing than its worth.
To be clear, it's just a reformulation of the math involved. Both formulations of GR/SR with and without variable mass create the same predictions. It's just that it keeps the concept of mass more coherent to stick with "mass is the energy of a particle at rest".
When the velocity is the speed of light, solving the equation of special relativity yields m of zero.
We have a successful theory of quantum mechanics which integrates with special relativity, so that definition holds, even if you take the same approach from an Effective Field Theory perspective.
The article you link starts off by defining mass as rest mass. I think the article shows very clearly that photons have no rest mass, using several different arguments.
However, a photon has energy, so therefore it must have not-at-rest mass. The article doesn't really comment on not-at-rest mass. We know photons interact with gravity because of gravitational lensing.
The calculation for mass zeros out as c is a divisor. You get zero for one of the coefficients of the mass calculation, which winds up making the whole thing zero.
The article doesn't have to comment on not-at-rest mass because the math is clear.
As for interacting with gravity, photons move through spacetime, and general relativity shows that gravity is the curvature of spacetime, and photons move on the shortest geodesic for that spacetime.
I'm not enough of a physicist to explain why this framing is wrong, but I took enough physics in college to know it absolutely is wrong.
Fun fact from my "Modern Physics" homework: a system of two photons can have mass, if they're traveling in different directions. In parallel though, they're still massless.
Most mass of massive objects doesn't come from the higgs mechanism. It's mostly the relativistic mass (?) of binding energy in protons and neutrons. So, I'm not sure the Higgs field needs to be involved at all.
I don't think I know the math well enough to answer the question definitively, but given my surface understanding of the Standard Model and GR... I think so (though I suspect "energy of coupling" is the wrong way to put it).
Radio waves are relatively low in negative mass along with photons.