Put a box into a mailbox that already holds one. You cannot. First the old box comes out, and now you are standing in the street holding it. The displacement did not consume the box; it relocated it, and it handed you a receipt you never asked for and cannot decline. Every physical move works this way. Matter does not vacate a coordinate. It goes somewhere, and the somewhere is a fact with an address.
Now erase a bit. The register resets. Landauer's Principle says that erasure cost at least kT ln 2 of heat, and the heat went into the bath. (Landauer's principle — Wikipedia) Nothing was destroyed. The energy is still in the room. But there is no longer a place you can point to and say there, that is where the one went. The bit did not leave a receipt. It left a temperature.
This is the distinction the erasure argument is usually asked to carry, and it usually breaks, because it is made too large. The large version says information is truly gone, that a computation must therefore degrade, and that the universe cannot be running one. That version does not survive contact. Quantum mechanics conserves information under unitary evolution, and the physicists are right about that. Reversible computation dissipates arbitrarily little -- Bennett showed logical reversibility was possible in 1973 and reviewed the thermodynamics in 1982 -- which means computation as such carries no obligation to leak. (Reversible computing — Wikipedia) Anyone arguing from erasure to the non-computability of the cosmos is arguing past two results that answered him before he started.
The small version survives. The small version is the one that pays.
Conservation is not address. Unitarity says the information is somewhere. It does not say where, and it does not promise that where is a place any instrument can reach. Those are separate claims, and every practice that matters -- audit, attestation, underwriting, blame -- needs the second one. An underwriter does not ask whether a record exists in principle somewhere in the light cone. He asks which coordinate to look at. An existence proof is not an address, and a system that can offer only the first has nothing to sell the second.
So the question was never whether the universe computes. That question has no experiment attached to it and no invoice at the end of it. The question is narrower and it is decidable: does this system's record have an address, or only an existence? The rock at the bottom of the hill has an address -- it is the address. The bit at the top of the register has an existence. Between those two sits every claim anyone will ever make about what an autonomous system did.
Drift, then, is not evidence about cosmology. It never was. Drift is evidence about the describer. When a description detaches from the thing it describes, the description keeps updating and the thing keeps moving and nothing in the description registers the separation -- because the description was never addressed to a coordinate to begin with. That is a measurable property of a machine we built, not a discovery about the machine we live in. The smaller claim is the one that can be checked, and checkable is worth more than grand.
You give: The satisfying argument that erasure disproves a computed universe. You get: The narrower one that survives a physicist -- and an address you can hand to someone who has to sign for it.
The heat is the receipt only when the heat has a coordinate. That is the whole of the patent, stated as a negative.