The photon travels from the emmitter to the detector. Along the way it bounces off a few mirrors and off or through a beam splitter or two. This journey takes time, but only from OUR perspective/frame. From the photon's point of view, it is always traveling at the speed of light. So, the same experimental setup, to the photon, undergoes (at the moment the photon is emmited from its parent atom) an instantaneous Lorentz transformation whereby the distance traveled by the photon is reduced to exactly 0. From the photon's point of view, since the distance traveled (and time elapsed) between being emitted and being absorbed are non-existent, then of course the photon knows what path it is going to take. There is never any question as to what path the photon is going to take because there is no path.
That's interesting, I think to myself...
The atom emitting the photon drops from an excited state to a lower energy state, one of its electrons drops down an orbital, and the aforementioned photon is emitted. From our perspective the photon flies around and does stuff for awhile before finally hitting another atom with (miracle of miracles) exactly the right amount of momentum/energy to be absorbed. But from the photon's perspective, the two atoms were touching each other. There was no distance to be traversed. The photon simply stepped from one atom to the next.
But wait a second, if the photon, from the photon's point of view, travels 0 meters over 0 seconds, does the photon really exist? And if the photon doesn't exist, well I guess I know how it can tell where it's going before it goes there... It's already arrived and been absorbed!
Oh no, I say to myself, I just convinced me that photons (and their accompanying pilot waves, if you're inclined to towards that particular interpretation) don't exist! Ok, ok, ok, don't panic. Have I ever actually seen a photon? Hmmmm... I've seen (pun intended) what happens when an atom absorbs a photon, but no, if I'm being honest with myself, then no, I've never actually seen a photon. Ok... have I ever directly observed an electromagnetic wave (or a wave function for that matter)? I guess I haven't (I'm not a member of the Vienna Circle, I swear!).
Well, what the heck?!
And then the voice of John Wheeler echos through my memory. "It from bit," John says. And then Claude Shannon's paraphrasing cousin chimes in, "remember grasshopper, information requires 3 things, a sender, a channel, and a receiver."
Well gosh, I think to myself, I happen to have those three things right here. I have a sender (the atom which emits the photon), the channel (the photon's journey through the experimental setup), and a receiver (the atom that absorbs the photon at the end of its flight). There's no particle, there's no wave, there's no spooky action at a distance or superluminal communication, there is ONLY a direct information transfer from one atom to the other. So, what does one atom say to the other atom? Well, I guess it would have to be a relatively (see what I did there?) simple statement... Perhaps it would be something like, "Hey! You! Yeah, you! Like, FYI dude! I'm here and you're, like, totally way over there dude! Isn't that radical?!"
I guess maybe it depends on what kind of atoms we're talking about...
In all seriousness though, that got me to thinking. Energy is being exchanged. Information is being exchanged. Information is energy, which in turn, is mass (btw, no wonder information can't be transmitted superluminally, right?!). If that's the case, and if mass and energy and information must be conserved, then by gosh, the information carried by the photon might (must?) encode information about the photon's source and its subsequent journey (which, as I established earlier, never occurred, at least not from the point of view of the nonexistent particle carrying said information). And since the amount of information can be calculated from the energy exchanged, then we know how much information (negentropy?) is being transferred between those two atoms!
So now I'm thinking about the temperature differentials between emitting and absorbing atoms and how the greater the temperature differential, the greater amount of information being exchanged. Where do we have the greatest temperature differential I ask myself? My mind jumps to the CMB and the surface of last scattering, which a quick google search tells me has a surface temperature of approximately 3000K. Lower than I thought, but that's one heck of a big surface to be that hot, so that's an awful lot of information to be had... A whole universe worth, one might say.
So, my question is, what's wrong with this interpretation of the Delayed Choice Experiment? Obviously something must be wrong with it or it wouldn't not exist (except in my head). It seems to me each step follows logically from its predecessor AND it seems like it neatly resolves the measurement problem as a side effect (since measurement can be clearly and concisely defined as the receipt of information that has been transmitted via a channel from a sender) AND it seems like it is the first step on the road to unraveling how our entire physical existence is generated directly from information. I didn't make any drastic assumptions or introduce any new axioms or use any of that fancy math stuff...
The closest interpretation of quantum mechanics that I've been able to find was Relational Quantum Mechanics. Am I just subconsciously regurgitating Carlo Rovelli? Has he weighed in on the delayed choice and double slit experiments?