Ask HN: What if the universe itself runs on O(1) memory?

I keep circling back to two facts that seem incompatible until you squint just right.

1- Turing says: any discrete procedure can be emulated on a tape that grows as needed. Irreversibility—and therefore information loss—is baked in.

2- David Deutsch: the physical world is fundamentally reversible; no bit of history is ever truly deleted.

Now to add in something I’ve only recently wrapped my head around: there’s a universal bound—a Bekenstein-style ceiling—on how much information any bounded region can hold. Past that, additional bits aren’t stored; they’re smeared into geometry, energy, and curvature. In other words, the universe enforces a topological limit on computation: you can keep calculating forever, but you must keep folding state back into the same finite fabric.

So, I think the right mental model isn’t “bigger tape, bigger RAM.” It’s topological transformations: moves that twist, braid, and refold the same patch of memory without tearing or gluing anything new. Every legal operation must be invertible, because tearing (irreversibility) would leak information past the bound.

I have a toy implementation of an O(1) VM—where the active cell set never exceeds a fixed small constant, no matter how many steps I run. Round-trip tests pass, and the tape stays sparse. It’s slow and fragile, so I wouldn’t ship it till I perfect it a bit more, but the geometry feels right and I can rewrite quite few algorithms from O(N) to O(1) trading memory for a bit of compute

Why share this? Because the idea reframes practicality - maybe we shouldn’t ask “how do we scale memory?” but “how do we braid computation inside the universal limit nature already imposes?” If that framing holds water, Turing gave us the floor, Deutsch gave us the ceiling, and I think I’m starting to stare towards the center

Curious if anyone else thinks this is more than philosophical exercise. Anyone else familiar with anything like this?