Alright, so the water becomes the energy transfer medium in the ideal pool model, meaning it goes on to
solely handle
all the energy transferred from the stone -- and it keeps handling it until frictional losses and so forth inevitably bleed the energy away. The guitar string becomes such a medium, handling all the energy transferred once plucked. The air then acts as a second medium which, through compression waves, transfers some of the energy from the vibrating string to one's ear components, which serially add more transfer mediums,.. until the brain finally gets the message in electrical signal form.
Hopefully that introduction will help some to better understand how light (energy) actually "travels" (is transferred) through the so-called "vacuum" of space. Energy transfer mediums do not guide otherwise independent forms of energy through them in the form of various waves. The mediums themselves transfer all of the energy through themselves. The water transfers all the energy given up by the stone through itself and by itself. A piano string transfers all the energy imparted once struck back and forth, through itself. In the next stage, the air grabs some of that energy and transfers it all by itself. The Ether therefore, being the only energy transfer medium possible in outer space, also must transfer all light energy
through itself, by itself.
That said, now:
With light, the initial photons at the source are transmitted in a wave rather than a straight line. Why?
Not true at all. First off, "photons" are QM speak for the amount of light energy the Ether can handle (transfer) in one shot due to its own density. The Ether's average density is highly uniform, say throughout at least the Milky Way galaxy, except where massive bodies like black holes reside. Massive objects attract the Ether causing it to be more dense locally. Supermassive objects cause the Ether to become super dense. The Earth's mass attracts the Ether which in turn pushes us toward Earth's gravitational center. Thus gravity.. despite it always feeling like the Earth itself is pulling on us instead.
"Electrons" and "photons" are, as some fart smellers still describe them today, just "probability clouds." In other words, simply discrete amounts of energy that we regularly detect as centered at certain places at certain times. No one has ever seen either and never will because they only exist as mathematical constructs. In theory, in other words. The energy is very real. The math is indubitably correct. The supposed objects themselves? All those "dual wave/particle" thingies? Sorry, they don't exist. Never have. Einstein nearly had it right, then went off the deep end and the entire business has been FUBAR since. J.J. Thompson immediately regretted coining the term "electron" after witnessing the mess people tended to make of it.
Anyways, like all the other supposed "subatomic particles" (excluding protons and neutrons), "electrons" and "photons" are simply unique manifestations of the Ether itself. I should note here that the Ether necessarily exists throughout both space
and counterspace. All energy emerges from and eventually sinks back into counterspace. All mass is confined within space. Counterspace literally means contrary to or the opposite of space. So, in a sense at least, more mass means more space and therefore more counterspace. Bigger black holes, for instance. So just to tie up this part with a fittingly ugly ribbon and bow, light does not travel anywhere. All energy (including all light energy) first gets transferred to a medium which then moves it entirely through itself in various ways.