Comment by yshklarov
1 day ago
Indeed. A "violation of logic and geometry"? Reading the author's own description, it's hard to see what the big deal is:
"Put a box around any region of space (space-time, really, but I’m going to drop time throughout this essay for ease of visualization, as physicists often do). The holographic principle asserts that no matter what’s going on inside — from gas molecules pinging around to black holes colliding — you can decipher the entire contents of the box just by repeatedly measuring points on the surface."
Well, if we're bounding a region of space-time then, in a purely classical universe governed by deterministic ODEs or PDEs, the statement reduces to a triviality: having information about the boundary amounts to knowing all boundary conditions. Of course I understand that this isn't really the statement of the holographic principle, but the article's formulation is rather underwhelming.
Say your boundary is a spherical shell, with a radially constant electric field. Based only on those boundary conditions, you cannot know the distribution of charges inside the shell. It could be a point charge, a solid sphere, a smaller shell, etc.
So classically you cannot decipher the entire contents of the box just from its surface!