Is it misunderstanding things to say that we're like data on a computer? So from my perspective, two atoms on my body are right next to each other. However, they could be theoretically encoded on opposite ends of the universe's 2d surface?
The analogy no one wants to state in public (because its partially wrong) is holography is like Fourier transforms or x-ray crystallography.
Today everyone is very chill with using FT to convert say a pile of voltage and time measurements into frequency/phase and power, and back again, and manipulate either side to see how the other side wiggles in response. This is all basic EE stuff this is how your DSP or software defined radio works (well, not exactly but close enough)
Photo negative human scale holograms use monochromatic light to store all kinds of interference pattern stuff into splotches of black and white. If we were (are?) smart enough we could print out something on photo paper and shine a laser on it and a hologram would appear.
Another analogy which is pretty decent is its like x-ray crystallography where about half a century ago a popular use of computers was to take a crystalline material and shine xrays thru it making a very modern art ish looking photo of holographic interference patterns (sorta) which would be analyzed by a computer to reverse the transform and turn it back into a 3-d model of the atoms in the crystal.
So a lot of this is almost cryptographic hash like in that flipping a couple bits on one side almost always results in a huge change on the other side.
So if instead of talking about atoms you take a film and laser hologram of two coffee cups the splotchy hologram film doesn't really have a concept anymore of two coffee cups next to each other, you can't point to a splotch and say thats the cup on the left. You definitely can't slice the film in half and project each and expect one cup on each half, probably you'll have two holograms each with two coffee cups and 3 dB or so worse signal to noise ratio.
Badly mixing analogies its like running a crypto algo on 2 bytes of data and asking where exactly the two bytes are in the output. Well, um, if the crypto algo is anything better than ROT13 they're both kinda smeared everywhere across the output of the algo.
Really badly mixing analogies its like taking a .scad file storing a 3d object (or stl or cad program of your choice) and encoding it into one of those legacy 2-D QR codes and then asking where in the QR code can you see your 3-d object ...
The whole point of this is we kinda sorta have a 2-d holographic picture of the cosmic background radiation sorta. Its a very distinct picture. So whatever crazy simulations we try, we'd best make sure if you hologram-ify the cosmic background radiation, it best look similar to what our telescope have already seen. Kind of like stellar astrophysics isn't just making stuff up, your theories better match what spectrum analysis of star light often actually looks like, if your nifty stellar astrophysics theory predicts Sirius is a red giant or a black hole or something then your theory is messed up because we have lots of data about the real Sirius as opposed to theoretical models.
