His example is different in a very particular way:
His conscious entity gets to dump photons into de Sitter space directly and only if you open it. This makes Scott's counter-claim prima facie basically plausible - if your putative consciousness only involves reversible actions, then is it really conscious?
But, I specifically drew a line between Alice and Alice's Room, and specified that Alice's normal operations are irreversible - but they must also dump entropy into the Room, taking in one of its 0 bits and returning something that might be 1 or 0, and if you feed her a 1 bit, she dies on waste heat (maybe she has some degree of tolerance for 1s, but as the density of 1s approaches 50% she cannot survive).
If you were to just leave the Room open all the time, always resetting its qbits to 0, Alice would operate the same, aside from having no risk of heatstroke. (In this case, of course, if you run the simulation backwards, the result would not be where you started, but catastrophe).
I think this is a pretty crucial distinction.
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At least that find explains why the comment disappeared without a ripple. It triggered "I've seen this before".
Yet another exceptionally interesting blog post by Scott Aaronson, describing his talk at the Quantum Foundations of a Classical Universe workshop, videos of which should be posted soon. Despite the disclaimer "My talk is for entertainment purposes only; it should not be taken seriously by anyone", it raises several serious and semi-serious points about the nature of conscious experience and related paradoxes, which are generally overlooked by the philosophers, including Eliezer, because they have no relevant CS/QC expertise. For example:
Scott also suggests a model of consciousness which sort-of resolves the issues of cloning, identity and such, by introducing what he calls a "digital abstraction layer" (again, read the blog post to understand what he means by that). Our brains might be lacking such a layer and so be "fundamentally unclonable".
Another interesting observation is that you never actually kill the cat in the Schroedinger's cat experiment, for a reasonable definition of "kill".
There are several more mind-blowing insights in this "entertainment purposes" post/talk, related to the existence of p-zombies, consciousness of Boltzmann brains, the observed large-scale structure of the Universe and the "reality" of Tegmark IV.
I certainly got the humbling experience that Scott is the level above mine, and I would like to know if other people did, too.
Finally, the standard bright dilettante caveat applies: if you think up a quick objection to what an expert in the area argues, and you yourself are not such an expert, the odds are extremely heavy that this objection is either silly or has been considered and addressed by the expert already.