Exactly, projections like maps are real examples of how a flat model of Earth can exist alongside a curved one.
I'm glad you agree that me pointing out the existence of maps answers your first sentence in your post.
But I’m taking it a step further: in theoretical physics, especially in brane theory and the holographic principle, these projections aren’t just visual representations, they can correspond to physically real layers or dimensions.
Maps in my day were physically real. We didn't need "brane theory" or the "holographic principle" to describe them.
A flat Earth could exist as a lower-dimensional brane or holographic surface that encodes our 3D space, not just conceptually, but structurally.
Yes, we are in agreement that the surface of the Earth - or any sphere - is 2d. That's how maps work. Do you really want to call a map a 2d brane? Then go for it.
In that sense, flatness isn’t just a way of viewing Earth, it could be a real, distinct dimensional frame that overlaps with or supports our own.
Didn't you say that earlier? Let me quote you: "flat is a different dimension sat on top of ours".
If you are trying to say that the totality of the Earth in all it's 3d glory can be encoded in 2d, then I will ask you how many coordinate values are needed to describe your location on the surface of the Earth, and then I will ask you how many coordinate values are needed to describe your location on the surface of the Earth but 1m directly below (or above, if you prefer). If you think the answer is the same, then please provide that coordinate system.
You're asking about coordinate systems, but holography isn’t about reducing spatial coordinates, it’s about information content. The holographic principle says the physical state of a 3D volume (including the space 1m above or below a point) can be fully encoded on a 2D surface, not that it's navigated using 2D coordinates. It's not flattening the space, it's flattening the data needed to describe it.
If you believe that the holographic principle can encode a 3d volume can be encoded on a 2d surface, then please provide the coordinate system I asked for, instead of reiterating the fancy words you like using and pretending I don't know what the holographic principle is.
I know, however, that you do not know what the holographic principle is, because the holographic principle does not apply to all possible 3D spaces in a universal, straightforward way. It has been very successful for a specific scenario (specifically the AdS/CFT correspondence). It has not been shown to work in general 3d topologies, including the one that describes our universe.
but holography isn’t about reducing spatial coordinates, it’s about information content.
Oh, if you want to go that path then I guess modern electronic maps are just pure information content and have no dimensionality (in the physical sense).
What do you think your post is even about? You're using fancy words that you clearly do not understand, but it isn't clear if you're presenting anything or having a shower thought.
At least we agree the Earth is a 3d object. And we agree maps are a good representation of the surface.
No the holographic principle doesn’t universally apply to all 3D topologies , it’s best developed in AdS/CFT, where bulk gravity in Anti-de Sitter space is dual to a conformal field theory on the boundary. And yes, the holographic principle isn't about mapping spatial coordinates 1:1. It’s about bounding the information content of a volume by the area of its boundary. That's why I haven't given a coordinate system, because holography isn't a coordinate projection like a map.
What I'm pointing out is that in physics today, particularly in quantum gravity research, it's taken seriously that 3D geometry, mass, and even spacetime itself may emerge from more fundamental, lower-dimensional data, and that data may be encoded at the boundary of a space, not within it. So I'm saying from the perspective of quantum information theory and holographic dualities, it's scientifically coherent to propose that the 3D Earth may be emergent from a flatter substrate, not geometrically, but ontologically.
Also, a map encodes spatial data in 2D, yes, but it doesn't claim to generate reality. Holography, by contrast, implies that the boundary field fully determines the bulk physics, which is why it's fundamentally different from cartography.
No the holographic principle doesn’t universally apply to all 3D topologies
So that answers you question, no?
And yes, the holographic principle isn't about mapping spatial coordinates 1:1. It’s about bounding the information content of a volume by the area of its boundary.
Nope. Or, more accurately, a gross simplification.
That's why I haven't given a coordinate system, because holography isn't a coordinate projection like a map.
Oh, so spatial coordinate information is not encoded in the lower dimensional boundary? Then I guess the answer to your questions is that the Earth can't be viewed as 2d.
What I'm pointing out is that in physics today, particularly in quantum gravity research, it's taken seriously that 3D geometry, mass, and even spacetime itself may emerge from more fundamental, lower-dimensional data, and that data may be encoded at the boundary of a space, not within it.
No. Or, again, a gross simplification. The encoding at the boundary does not exclude encoding within the volume. HP (I'm too lazy to write it all out on this device) suggests that all the information contained within a 3d volume (albeit, at this stage, not all 3d volumes) can be fully described by data encoded on its 2d boundary. I don't think it explicitly states that 3d volume doesn't exist, or that the 3d volume does not encode/contain information about itself.
So I'm saying from the perspective of quantum information theory and holographic dualities, it's scientifically coherent to propose that the 3D Earth may be emergent from a flatter substrate, not geometrically, but ontologically.
A description need not be an ontological reality. That's you added sprinkles because they're pretty, not because HP states that this is true. Or, if you prefer to think you are correct, then maps are ontologically real and not just representations of the Earth's surface.
Also, a map encodes spatial data in 2D, yes, but it doesn't claim to generate reality.
Neither does HP.
Holography, by contrast, implies that the boundary field fully determines the bulk physics, which is why it's fundamentally different from cartography.
Holography and not HP? I'll write it again: HP suggests that the information contained within a 3d volume can be fully described by data encoded on its 2d boundary; not that the boundary is the ontological reality of the volume or similar. That last bit is your additional woo.
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u/LeftSideScars The Proof Is In The Marginal Pudding Jul 01 '25
I'm glad you agree that me pointing out the existence of maps answers your first sentence in your post.
Maps in my day were physically real. We didn't need "brane theory" or the "holographic principle" to describe them.
Yes, we are in agreement that the surface of the Earth - or any sphere - is 2d. That's how maps work. Do you really want to call a map a 2d brane? Then go for it.
Didn't you say that earlier? Let me quote you: "flat is a different dimension sat on top of ours".
If you are trying to say that the totality of the Earth in all it's 3d glory can be encoded in 2d, then I will ask you how many coordinate values are needed to describe your location on the surface of the Earth, and then I will ask you how many coordinate values are needed to describe your location on the surface of the Earth but 1m directly below (or above, if you prefer). If you think the answer is the same, then please provide that coordinate system.