The theory that we are holograms projected into three dimensional spacetime from a two dimensional surface is an intriguing possibility. It's a great thought experiment but one that I find hard to believe. This is mostly because the supposed surface whose information we are projected from is the CMB (cosmic microwave background).
This is the two dimensional representation of the inner wall of a sphere of photons we can observe from just after the reionisation event when the observable universe first became translucent to electromagnetic radiation.
While this, in itself, is not a reason for the theory to break down, the intervening time and light generated by other matter is. If we were a hologram from the surface of the CMB then information from the progression of stars over time would not be simultaneously observable. i.e. We can view the light from the CMB at the same time as viewing light from Alpha Centauri or our own star. This is essentially our ability to see multiple snapshots in time all superimposed on top of one another.
A hologram is generated from a still arrangement of information on a plane of dimention 'n' to a plane of dimension 'n+1' in order to simulate an arrangement of information in the plane of dimension 'n+1'. The arrangement of information (let's just call it an 'object' for brevity's sake!) or object in the 'n+1' plane doesn't really exist in that plane but it also doesn't evolve with time because the viewing of the object in the 'n+1' plane requires information transfer from within that plane in order to extrapolate the 'object' from plane 'n'. In order for the object to evolve both in plane 'n' and thus in plane 'n+1' then a projection source in plane 'n+1' must exist and transmit that change in information.
If that sounds a bit convoluted, let me explain in a more tangible way:
If you have a flat, 2D hologram information source of an object on your credit card, it is just 2D information until visible light from our 3D existence interacts with it and allows the differently reflected/refracted information to reach our eyes and provide the illusion of a 3D object. That is the transfer of information. However, even though that transfer of information is limited by the speed of light it is a temporal transfer of information.
Let me explain with a more complicated and, perhaps, complete, example:
If you have a more complex hologram - say intersecting light beams on a glass surface or cloud of gas or smoke, the information the light is transferring can be updated to provide the illusion of an object that is changing with time. e.g. see Pepper's Ghost or the Michael Jackson hologram for an example of this. The problem here is that only current information is transmitted by the light: the information is temporal and, at the intersection of the information, only 'current' information is passed.
If we extrapolate this information transfer process to the size of the observable universe then we have a problem. Okay, yes, assuming that a hologram can be viewed over an infinite angle and distance (usually this isn't the case) positions nearer to the information surface will have more recently updated information and positions further away to the surface will have older information. This is due to the limitation of the speed of light (which is also expected to limit all information transfer - not just that of light) and the distances which must be travelled to reach our location in the observable universe.
This is backwards to what we see.
We observe information from further in the past the further from us the light travels. Further to that, we see information in every direction in a more or less equal volume/distance. If we are receiving information on a two dimensional surface then that works for some directions, but not all and our projection into the three dimensional volume would also reflect that. After all, a hologram of an object in the nth dimension cannot make a complete object in the nth+1 dimension because it lacks complete data for all possible surfaces in the nth+1 dimension.
The hologram on your credit card, Pepper's Ghost and hologram Michael Jackson are all spatially limited. You cannot move around them completely in the 3D world without the hologrammatic illusion breaking and being revealed. Sure, the organisers can rig the projection systems to move with you and change the output orientation to simulate what you would expect to observe as you travelled around that object but even a hologram itself would be unable to work within that nth+1 dimension because information does not travel back to itself.
All of this reasoning ultimately leads me to conclude that we are not and cannot be holograms produced from information on a surface. Let alone a surface that is imaginary.
Let me explain that one: The CMB is not a surface in any true sense. It is just the point at which the oldest photons that have arrived at Earth from the point at which the reionisation event occurred for any given point in time. i.e. The longer we exist and observe, the older the photons arriving to our observatories will be and the larger the volume of the observable universe is.
This means that the 'surface' of the CMB is always getting larger (not even accounting for the 'inflation' of the observable universe) and isn't represented by the same light sources because as time goes on, new light from ever distant sources will reach us - however faintly!
I also believe that these limitations put paid the theory that we live in a simulation as a hologram is effectively a simulation. We need to be composed of the very substance that the original reality is made of in order to exist and, as such, will never be a simulation because we will be an exact recreation of reality if we are modelled perfectly.
If we are not modelled perfectly; if there are aspects of reality that are removed from our simulation then that also does not matter because, as I will point out in a future Sci-fi Tropes article, the universe doesn't actually exist anyway. There is no time - no change.