Once you’ve asked about decoherence and irreversibility, that immediately raises the question of whether these are what we’re aiming at, or something usually very closely related—or indeed whether these are the same thing at all! Suppose we have a quantum computer with three parts, each much larger than the previous.
Alice is a simulation of a putatively conscious entity. Suppose that the only reason we’d have not to think it’s conscious is what we’re about to do to it.
Alice’s Room is an entropy sink Alice will interact with in the process of its being putatively conscious
In order to run Alice and Alice’s Room, we also have an entropy sink we use for error correction.
We run Alice and Alice’s Room forwards in time for a while, and Alice is doing a bunch of locally-irreversible computations, dumping the resulting entropy into Alice’s Room instead of outer space.
At some point, we quantum-randomly either:
1) let Alice’s Room shed entropy into outer space, causing the local irreversibility to become permanent, or
2) we time-reverse the dynamics of Alice and Alice’s Room until we reach the initial state.
Was Alice conscious in case 1? In case 2? Since the sequence of events in both cases were in fact the same exact sequence of events—not merely identical, but referring to the exact same physically realized sequence of events—up to our quantum coinflip, it’s nonsense to say that one was conscious and the other was not.
So yes, consciousness is connected to the arrow of time, but on a local level, not necessarily on the billion-year scale.
This lets us spit out that bullet about the Anti-deSitter space. If you’re in an AdS space, you’re going to choke on your own waste heat a zillion years before quantum billiards brings you back close to the starting point.
So, I’d say that there’s consciousness inside this AdS trap, for a little while, until they die. When quantum billiards has again randomly lowered entropy to the point that a potentially conscious entity might have an entropy sink, then you can again have consciousness.
So, the AdS sphere is 99.999...(insert a lot)..99% not conscious, on account of its being dead, not on account of its being quantum-reversible.
wolfgang proposed a similar example on Scott’s blog:
I wonder if we can turn this into a real physics problem:
1) Assume a large-scale quantum computer is possible (thinking deep thoughts, but not really self-conscious as long as its evolution is fully unitary).
2) Assume there is a channel which allows enough photons to escape in such a way to enable consciousness.
3) However, at the end of this channel we place a mirror – if it is in the consciousness-OFF position the photons are reflected back into the machine and unitarity is restored, but in the consciousness-ON position the photons escape into the deSitter universe.
4) As you can guess we use a radioactive device to set the mirror into c-ON or c-OFF position with 50% probability.
Will the quantum computer now experience i) a superposition of
consciousness and unconsciousness or ii) will it always
have a “normal” conscious experience or iii) will it have a conscious experience in 50% of the cases ?
Scott responded that
I tend to gravitate toward an option that’s not any of the three you listed. Namely: the fact that the system is set up in such a way that we could have restored unitarity, seems like a clue that there’s no consciousness there at all—even if, as it turns out, we don’t restore unitarity.
This answer is consistent with my treatment of other, simpler cases. For example, the view I’m exploring doesn’t assert that, if you make a perfect copy of an AI bot, then your act of copying causes the original to be unconscious. Rather, it says that the fact that you could (consistent with the laws of physics) perfectly copy the bot’s state and thereafter predict all its behavior, is an empirical clue that the bot isn’t conscious—even before you make a copy, and even if you never make a copy.
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.
...
At least that find explains why the comment disappeared without a ripple. It triggered “I’ve seen this before”.
Was Alice conscious in case 1? In case 2? Since the sequence of events in both cases were in fact the same exact sequence of events—not merely identical, but referring to the exact same physically realized sequence of events—up to our quantum coinflip, it’s nonsense to say that one was conscious and the other was not.
that you and I are conscious seems like a pretty clear paradigm-case. On the other hand, that you and I would still be conscious even if there were aliens who could perfectly copy, predict, reverse, and cohere us (very likely by first uploading us into a digital substrate), seems far from a paradigm-case. If anything, it seems to me like a paradigmatic non-paradigm-case.
I disagree with his caveat for consciousness, since I would like to think of myself as conscious even if I am a simulation someone can run backwards, but I am not 100% sure, because reversibility changes the game considerably. Scott alludes to it in the Schrodinger’s cat experiment, by noting that death becomes reversible (in the QM-sense, not the cryonic sense), and thus largely loses its meaning:
I claim that there’s no animal cruelty at all in the Schrödinger’s cat experiment. And here’s why: in order to prove that the cat was ever in a coherent superposition of |Alive〉 and |Dead〉, you need to be able to measure it in a basis like {|Alive〉+|Dead〉,|Alive〉-|Dead〉}. But if you can do that, you must have such precise control over all the cat’s degrees of freedom that you can also rotate unitarily between the |Alive〉 and |Dead〉 states. (To see this, let U be the unitary that you applied to the |Alive〉 branch, and V the unitary that you applied to the |Dead〉 branch, to bring them into coherence with each other; then consider applying U-1V.) But if you can do that, then in what sense should we say that the cat in the |Dead〉 state was ever “dead” at all? Normally, when we speak of “killing,” we mean doing something irreversible—not rotating to some point in a Hilbert space that we could just as easily rotate away from.
Since this changes at least one fundamental concept, I am reluctant to state that it cannot apply to another.
He was willing to bite a big bullet to defend the definition he used. I just applied the definition he’d used, and plopped a much fatter bullet on his plate.
To recap—He would interpret the same sequence of past physical states as conscious or not depending on which branch of a later quantum split he ended up in.
Meanwhile, I provided an alternate very similar interpretation that maintains all of the benefits I can discern of his formulation and dodges both bullets.
Once you’ve asked about decoherence and irreversibility, that immediately raises the question of whether these are what we’re aiming at, or something usually very closely related—or indeed whether these are the same thing at all! Suppose we have a quantum computer with three parts, each much larger than the previous.
Alice is a simulation of a putatively conscious entity. Suppose that the only reason we’d have not to think it’s conscious is what we’re about to do to it.
Alice’s Room is an entropy sink Alice will interact with in the process of its being putatively conscious
In order to run Alice and Alice’s Room, we also have an entropy sink we use for error correction.
We run Alice and Alice’s Room forwards in time for a while, and Alice is doing a bunch of locally-irreversible computations, dumping the resulting entropy into Alice’s Room instead of outer space.
At some point, we quantum-randomly either: 1) let Alice’s Room shed entropy into outer space, causing the local irreversibility to become permanent, or 2) we time-reverse the dynamics of Alice and Alice’s Room until we reach the initial state.
Was Alice conscious in case 1? In case 2? Since the sequence of events in both cases were in fact the same exact sequence of events—not merely identical, but referring to the exact same physically realized sequence of events—up to our quantum coinflip, it’s nonsense to say that one was conscious and the other was not.
So yes, consciousness is connected to the arrow of time, but on a local level, not necessarily on the billion-year scale.
This lets us spit out that bullet about the Anti-deSitter space. If you’re in an AdS space, you’re going to choke on your own waste heat a zillion years before quantum billiards brings you back close to the starting point.
So, I’d say that there’s consciousness inside this AdS trap, for a little while, until they die. When quantum billiards has again randomly lowered entropy to the point that a potentially conscious entity might have an entropy sink, then you can again have consciousness.
So, the AdS sphere is 99.999...(insert a lot)..99% not conscious, on account of its being dead, not on account of its being quantum-reversible.
wolfgang proposed a similar example on Scott’s blog:
Scott responded that
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.
...
At least that find explains why the comment disappeared without a ripple. It triggered “I’ve seen this before”.
Well, Scott disagrees:
I disagree with his caveat for consciousness, since I would like to think of myself as conscious even if I am a simulation someone can run backwards, but I am not 100% sure, because reversibility changes the game considerably. Scott alludes to it in the Schrodinger’s cat experiment, by noting that death becomes reversible (in the QM-sense, not the cryonic sense), and thus largely loses its meaning:
Since this changes at least one fundamental concept, I am reluctant to state that it cannot apply to another.
He was willing to bite a big bullet to defend the definition he used. I just applied the definition he’d used, and plopped a much fatter bullet on his plate.
To recap—He would interpret the same sequence of past physical states as conscious or not depending on which branch of a later quantum split he ended up in.
Meanwhile, I provided an alternate very similar interpretation that maintains all of the benefits I can discern of his formulation and dodges both bullets.
Consider posting your comment on his blog.
Too bad he didn’t consider it worth replying to (yet?)
Too bad indeed. In my experience, if he hasn’t within a day or so, he won’t.
Funny, I just came here to copy it for that purpose.