Art by smbc-comics
Consciousness is often said to disappear in deep, dreamless sleep. We argue that this assumption is oversimplified. Unless dreamless sleep is defined as unconscious from the outset there are good empirical and theoretical reasons for saying that a range of different types of sleep experience, some of which are distinct from dreaming, can occur in all stages of sleep.
Pubmed Articles
Does Consciousness Disappear in Dreamless Sleep?
Sciencealert Article We Were Wrong About Consciousness Disappearing in Dreamless Sleep, Say Scientists
I would argue that two disconnected copies of the information that corresponds to a person does make 2 disjoint persons.
Like running a different seed on procedural generation, entropy will ensure that these two identical persons won't be identical after whatever ticks in the biological clock.
I agree that the copies will diverge almost instantly; I'm just saying that small amounts of divergence aren't a big deal. That's what I'm trying to illustrate with my example of the person who loses an hour of memories. I think this is exactly equivalent to making a copy, having that copy exist for an hour, and then destroying it. An hour of memories does make the copy different from the original, but the loss of the copy is just the loss of that hour, not of a complete human being (and we naturally quickly forget much more than that - I already can't remember what I did every hour yesterday).
I admit I don't feel like it's exactly equivalent, but I think that's an illusion caused by my moral intuitions developing in a wold where destroying a copy always means destroying the only copy.
Though the simpler solution is that perhaps memory formation is paused over the period then the person 'lost' their memory to sleep.
Losing memories when you're wide awake is like a file system deleting pointers to a file. The file is still there, just inaccessible.
Anyways I feel that the assertion that "Creating and destroying perfectly identical copies of the information that corresponds to a person neither creates nor destroys people" is extremely dangerous thinking that could lead to the premature end of consciousness for some very unfortunate individuals. After all, they're perfectly identical and we have no documented instance of anyone sharing consciousness, so it may be that consciousness are unique and not commutative.