Light spots and shadows
If a laser beam is swept across a distant object, the spot of laser light can easily be made to move across the object at a speed greater than c. A gravitational constant that is the same
everywhere in the universe and is incompatible
with a fifth force.
The fallout of this ramification is that, gravity is some sort of ambient side effect of material presence, sort of like a shadow cast, more than an emission radiated.
You might be in love with the idea of describing an equation that frames the gradient of distribution, and the nature of it's propagation through a medium, but the sound wave is the manner in which the gaseous molecular constituents of the air are set in motion relative to one another. They get closer, they move apart, the changes occur at different places in the medium, at different times, and do so at a certain velocity, in sequence as interactions are forced upon the medium.
Indeed, the reason sound waves travel at the speeds we observe, is because that's how fast the very molecules themselves, comprising the air, are moving at the temperature and pressure of the environment.
Meanwhile, what color is a beam with a wavelength of one nanometer? Would you characterize the color as "soft x-ray"?