More from Specialist290, because it’s post-dinner:

A few small questions regarding pattern identity and the metaphysics thereof:

1. Are there any possible scenarios where two forks of the same personality can diverge from one another significantly enough for them to be regarded as different persons, when the result of either individual pattern shift would not have resulted in enough variation in the pre-fork pattern to constitute a legal change in identity?

In the fork case, it’s the divergence that matters. Actually, it’s almost always the divergence that matters – usually, the only time you’re comparing to a backup is immediately post-reinstantiation to check that the process was carried out correctly, or in the event of some accident or missing-person scenario when there’s some doubt.

Anyway, for fork divergence, it’s always difference from each other that matters. Difference from some pre-fork backup is irrelevant.

2. A purely hypothetical case:  If, without the intervention of any causal agency, two individuals are found to have such closely-matching patterns of personality that one would have been considered a fork of the other had one been created as an act of will, would they still be legally the same person? (Put another way:  If, by blind chance, someone had such a fundamentally identical life experience to your own that your memories would be practically interchangeable to the extent that you could easily mistake your memories for theirs and write off any divergences as a product of your own faults in recollection, would the two of you be considered the same person?)

(Put yet another way:  Could a doppelganger fork arise out of pure synchronicity?)

Hypothetically, yes, they would be – although they would have to be identical on a rather deeper level than just consciously recalled memories. As the legal and philosophical principle puts it, íthal íthalavar: “A is A”, or “a thing is itself”. Two things equal to the same thing are equal to each other.

Of course, a quick back-of-the-envelope calculation based off the number of bits contained in any one mind-state vector suggests that this could happen considerably less often than once per universe-lifetime, so it’s not like there’s case law on the point…

And Mark Atwood asks:

Which reminds me of an ongoing question I’ve been having. Is being the a member of the Imperial Couple a time-limited term of service, or is it “until (permanent?) death, abdication, or removal”. Given they were immortal even before the tech takeoff, someone could end up being the Lord of some city state for a very very very very long time…

There are no term limits for that particular office. (Or most, but there’s a fair amount of diversity so I’m not saying there are none anywhere.) By wording of the Imperial Charter, you can have it until death, permanent incapacity, abdication, or impeachment.

That said, they are subject to the not-a-law-but-relatively-firm-custom of the Six-Century Rule which suggests to everyone that you find a new career after three centuries¹, i.e. 432 Imperial years, if they haven’t done so already. That was never a firm term limit for anyone mostly because if it required someone to leave in the middle of a crisis, that would be a bad idea, right?

So, anyway, I had the dates of the first 15 Imperial Couples handy, and the average reign is rather shorter at 285 years, almost entirely due to abdications. (High of 505 – Alphas I, making sure his empire stuck – and low of 100.) That is almost entirely because it’s a really damned hard job that would age you quickly if you, well, could. I imagine it’s quite a relief to be an Emperor Emeritus with no more pressing Imperial obligations than to sit in the Privy Council and quietly kibitz.

(I’m sure there are some veryⁿ old rulers around in various backwaters, though. I don’t think anyone minds, or in most cases, has noticed.)

Footnotes:

1. Because they changed the calendar after they made the rule. The Calendar of Rhoës used 72-year centuries. Of course, no-one but scholars has used said calendar for nearly 8,000 years at this point, so the main function of the name these days is to confuse and disorient people learning about it who aren’t masters of horological trivia.