I feel much the same about this post as I did about Roko's Final Post. It's imaginative, it's original, it has an internal logic that manages to range from metaphysics to cosmology; it's good to have some crazy-bold big-picture thinking like this in the public domain; but it's still wrong, wrong, wrong. It's an artefact of its time rather than a glimpse of reality. The reason it's nonetheless interesting is that it's an attempt to grasp aspects of reality which are not yet understood in its time - and this is also why I can't prove it to be "wrong" in a deductive way. Instead, I can only oppose my postulates to the author's, and argue that mine make more sense.
First I want to give a historical example of human minds probing the implications of things new and unknown, which in a later time became familiar and known. The realization that the other planets were worlds like Earth, a realization we might date from Galileo forwards, opened the human imagination to the idea of other worlds in the sky. People began to ask themselves: what's on those other worlds, is there life, what's it like; what's the big picture, the logic of the situation. In the present day, when robot pro...
The philosophical implication is that actually running such an algorithm on an infinite Turing Machine would have the interesting side effect of actually creating all such universes.
That's an interesting point! At least, it's more interesting than Tipler's way of arriving at that conclusion.
If you accept that the reasonable assumption of progress holds, then AIXI implies that we almost certainly live in a simulation now.
See my response to the claim that the anthropic argument suggests it is highly improbable that you would find yourself to be a hum...
The set of simulation possibilities can be subdivided into PHS (posthuman historical), AHS (alien historical), and AFS (alien future) simulations (as posthuman future simulation is inconsistent).
What these categories meant was not clear to me on first reading.
I currently understand AFS as something like aliens finding earlier [humanity[ and trying to predict what we will do. AHS would be the result of Aliens interacting with a more mature humanity and trying to deduce particulars about our origin, perhaps for use in an AFS.
If I have that right, PFS migh...
If you absolutely have to summarize the forbidden topic at least rot13 it and preface it with an appropriate warning.
I have a question. What does it mean for AIXI to be the optimal time bounded AI? If it's so great, why do people still bother with ANNs and SVNs and SOMs and KNNs and TLAs and T&As? My understanding of it is rather cloudy (as is my understanding of all but the last two of the above), so I'd appreciate clarifaction.
First of all, AIXI isn't actually "the optimal time bounded AI". What AIXI is "optimal" for is coming to correct conclusions when given the smallest amount of data, and by "optimal" it means "no other program does better than AIXI in at least one possible world without also doing worse in another".
Furthermore AIXI itself uses Solomonoff induction directly, and Solomonoff induction is uncomputable. (It can be approximated, though.)
AIXItl is the time-limited version if AIXI, but it amounts to "test all the programs that you can, find the best one, and use that" - and it's only "optimal" when compared against the programs that it can test, so it's not actually practical to use, either.
(At least, that's what I could gather from reading the PDF of the paper on AIXI. Could someone who knows what they're talking about correct any mistakes?)
because the runtime complexity of AIXI is astronomically larger than the universe is.
'Astronomically'? That's the first time I've seen that superlative inadequate for the job.
Memetic hazard warning. Decode first part first.
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I'm not saying that all or even most of the information content of adult morality is in the genome.
Right, so we agree on that then.
If I was going to simplify - our emotional systems and the main associated neurotransmitter feedback loops are the genetic harnesses that constrain the otherwise overly general cortex and its far more complex, dynamic memetic programs.
We have these simple reinforcement learning systems to avoid pain-causing stimuli, pleasure-reward, and so on - these are really old conserved systems from the thalamus that have maintained some level of control and shaping of the cortex as it has rapidly expanded and taken over.
You can actually disable a surprising large number of these older circuits (through various disorders, drugs, injuries) and still have an intact system: - physical pain/pleasure, hunger, yes even sexuality.
And then there are some more complex circuits that indirectly reward/influence social behaviour. They are hooks though, they don't have enough complexity to code for anything as complex as language concepts. They are gross, inaccurate statistical manipulators that encourage certain behaviours apriori
If these 'things' could talk, they would be constantly telling us to: (live in groups, groups are good, socializing is good, share information, have sex, don't have sex with your family, smiles are good, laughter is good, babies are cute, protect babies, it's good when people like you, etc etc.)
Another basic drive appears to be that for learning itself, and its interesting how far that alone could take you. The learning drive is crucial. Indeed the default 'universal intelligence' (something like AIXI) may just have the learning drive taken to the horizon. Of course, that default may not necessarily be good for us, and moreover it may not even be the most efficient.
However, something to ponder is that the idea of "taking the learning drive" to the horizon (maximize knowledge) is surprisingly close to the main cosmic goal of most transhumanists, extropians, singularitans, etc etc. Something to consider: perhaps there is some universal tendency towards a universal intelligence (and single universal goal).
Looking at it this way, scientists and academic types have a stronger than usual learning drive, closely correlated with higher-than-average intelligence. The long standing ascetic and monastic traditions in human cultures show how memetics can sometimes override the genetic drives completely, resulting in beings who have scarified all genetic fitness for memetic fitness. Most scientists don't go to that extreme, but it is a different mindset - and the drives are different.
If the emotions and basic drives are different, the values learned will be different
Sure, but we don't need all the emotions and basic drives. Even if we take direct inspiration from the human brain, some are actually easy to remove - as mentioned earlier. Sexuality (as a drive) is surprisingly easy to remove (although certainly considered immoral to inflect on humans! we seem far less concerned with creating asexual AIs) along with most of the rest.
The most important is the learning drive. Some of the other more complex social drives we may want to keep, and the emotional reinforcement learning systems in general may actually just be nifty solutions to very challenging engineering problems - in which case we will keep some of them as well.
I don't find your 2^1024 analysis useful - the space of possible drives/brains created by the genome is mainly empty - almost all designs are duds, stillbirths.
We aren't going to be randomly picking random drives from a lottery. We will either be intentionally taking them from the brain, or intentionally creating new systems.
If the AI isn't comforted by physical contact, that's at least few bytes of the drive description that's different than the description that matches our drives. That difference throws out a huge chunk of how our morality has evolved to instill itself.
There is probably a name for this as a 'disorder', but I had a deep revulsion of physical contact as a child. I grew out of this to a degree later. I don't see the connection to morality.
That difference throws out a huge chunk of how our morality has evolved to instill itself.
Part of the problem here is morality is a complex term.
The drives and the older simpler control systems in the brain do not operate at the level of complex linguistic concepts - that came much much later. They can influence our decisions and sense of right/wrongness for simple decisions especially, but they have increasingly less influence as you spend more time considering the problem and developing a more complex system of ethics.
We might still be able to get an alien mind to adopt all the complex values we have, but we would have to translate the actions we would normally take into actions that match alien emotions.
alien mind? Who is going to create alien minds? There is the idea of running some massive parallel universe sim to evolve intelligence from scratch, but thats just silly from a computational point of view.
The most likely contender at this point is reverse engineering the brain, and to the extent that human morality has some genetic tweaked-tendencies, we can get those by reverse engineering the relevant circuits.
But remember the genetically preserved emotional circuits are influencers on behavior, but minor, and are not complex enough to cope with abstract linguistic concepts.
Again again, there is nothing in the genome that tells you that slavery is wrong, or that human sacrifice is wrong, or that computers can have rights.
Those concepts operate an entire new plane which the genome does not participate in.
I'm not talking about the genome.
1024 bits is an extremely lowball estimate of the complexity of the basic drives and emotions in your AI design. You have to create those drives out of a huge universe of possible drives. Only a tiny subset of possible designs are human like. Most likely you will create an alien mind. Even handpicking drives: it's a small target, and we have no experience with generating drives for even near human AI. The shape of all human like drive sets within the space of all possible drive sets is likely to be thin and complexly twist...
Implications of the Theory of Universal Intelligence
If you hold the AIXI theory for universal intelligence to be correct; that it is a useful model for general intelligence at the quantitative limits, then you should take the Simulation Argument seriously.
AIXI shows us the structure of universal intelligence as computation approaches infinity. Imagine that we had an infinite or near-infinite Turing Machine. There then exists a relatively simple 'brute force' optimal algorithm for universal intelligence.
Armed with such massive computation, we could just take all of our current observational data and then use a particular weighted search through the subspace of all possible programs that correctly predict this sequence (in this case all the data we have accumulated to date about our small observable slice of the universe). AIXI in raw form is not computable (because of the halting problem), but the slightly modified time limited version is, and this is still universal and optimal.
The philosophical implication is that actually running such an algorithm on an infinite Turing Machine would have the interesting side effect of actually creating all such universes.
AIXI’s mechanics, based on Solomonoff Induction, bias against complex programs with an exponential falloff ( 2^-l(p) ), a mechanism similar to the principle of Occam’s Razor. The bias against longer (and thus more complex) programs, lends a strong support to the goal of String Theorists, who are attempting to find a simple, shorter program that can unify all current physical theories into a single compact description of our universe. We must note that to date, efforts towards this admirable (and well-justified) goal have not born fruit. We may actually find that the simplest algorithm that explains our universe is more ad-hoc and complex than we would desire it to be. But leaving that aside, imagine that there is some relatively simple program that concisely explains our universe.
If we look at the history of the universe to date, from the Big Bang to our current moment in time, there appears to be a clear local telic evolutionary arrow towards greater X, where X is sometimes described as or associated with: extropy, complexity, life, intelligence, computation, etc etc. Its also fairly clear that X (however quantified) is an exponential function of time. Moore’s Law is a specific example of this greater pattern.
This leads to a reasonable inductive assumption, let us call it the reasonable assumption of progress: local extropy will continue to increase exponentially for the foreseeable future, and thus so will intelligence and computation (both physical computational resources and algorithmic efficiency). The reasonable assumption of progress appears to be a universal trend, a fundamental emergent property of our physics.
Simulations
If you accept that the reasonable assumption of progress holds, then AIXI implies that we almost certainly live in a simulation now.
As our future descendants expand in computational resources and intelligence, they will approach the limits of universal intelligence. AIXI says that any such powerful universal intelligence, no matter what its goals or motivations, will create many simulations which effectively are pocket universes.
The AIXI model proposes that simulation is the core of intelligence (with human-like thoughts being simply one approximate algorithm), and as you approach the universal limits, the simulations which universal intelligences necessarily employ will approach the fidelity of real universes - complete with all the entailed trappings such as conscious simulated entities.
The reasonable assumption of progress modifies our big-picture view of cosmology and the predicted history and future of the universe. A compact physical theory of our universe (or multiverse), when run forward on a sufficient Universal Turing Machine, will lead not to one single universe/multiverse, but an entire ensemble of such multi-verses embedded within each other in something like a hierarchy of Matryoshka dolls.
The number of possible levels of embedding and the branching factor at each step can be derived from physics itself, and although such derivations are preliminary and necessarily involve some significant unknowns (mainly related to the final physical limits of computation), suffice to say that we have sufficient evidence to believe that the branching factor is absolutely massive, and many levels of simulation embedding are possible.
Some seem to have an intrinsic bias against the idea bases solely on its strangeness.
Another common mistake stems from the anthropomorphic bias: people tend to image the simulators as future versions of themselves.
The space of potential future minds is vast, and it is a failure of imagination on our part to assume that our descendants will be similar to us in details, especially when we have specific reasons to conclude that they will be vastly more complex.
Asking whether future intelligences will run simulations for entertainment or other purposes are not the right questions, not even the right mode of thought. They may, they may not, it is difficult to predict future goal systems. But those aren’t important questions anyway, as all universe intelligences will ‘run’ simulations, simply because that precisely is the core nature of intelligence itself. As intelligence expands exponentially into the future, the simulations expand in quantity and fidelity.
The Assemble of Multiverses
Some critics of the SA rationalize their way out by advancing a position of ignorance concerning the set of possible external universes our simulation may be embedded within. The reasoning then concludes that since this set is essentially unknown, infinite and uniformly distributed, that the SA as such thus tells us nothing. These assumptions do not hold water.
Imagine our physical universe, and its minimal program encoding, as a point in a higher multi-dimensional space. The entire aim of physics in a sense is related to AIXI itself: through physics we are searching for the simplest program that can consistently explain our observable universe. As noted earlier, the SA then falls out naturally, because it appears that any universe of our type when ran forward necessarily leads to a vast fractal hierarchy of embedded simulated universes.
At the apex is the base level of reality and all the other simulated universes below it correspond to slightly different points in the space of all potential universes - as they are all slight approximations of the original. But would other points in the space of universe-generating programs also generate observed universes like our own?
We know that the fundamental constants in the current physics are apparently well-tuned for life, thus our physics is a lone point in the topological space supporting complex life: even just tiny displacements in any direction result in lifeless universes. The topological space around our physics is thus sparse for life/complexity/extropy. There may be other topological hotspots, and if you go far enough in some direction you will necessarily find other universes in Tegmark’s Ultimate Ensemble that support life. However, AIXI tells us that intelligences in those universes will simulate universes similar to their own, and thus nothing like our universe.
On the other hand we can expect our universe to be slightly different from its parent due to the constraints of simulation, and we may even eventually be able to discover evidence of the approximation itself. There are some tentative hints from the long-standing failure to find a GUT of physics, and perhaps in the future we may find our universe is an ad-hoc approximation of a simpler (but more computationally expensive) GUT theory in the parent universe.
Alien Dreams
Our Milky Way galaxy is vast and old, consisting of hundreds of billions of stars, some of which are more than 13 billion years old, more than three times older than our sun. We have direct evidence of technological civilization developing in 4 billion years from simple protozoans, but it is difficult to generalize past this single example. However, we do now have mounting evidence that planets are common, the biological precursors to life are probably common, simple life may even have had a historical presence on mars, and all signs are mounting to support the principle of mediocrity: that our solar system is not a precious gem, but is in fact a typical random sample.
If the evidence for the mediocrity principle continues to mount, it provides a further strong support for the Simulation Argument. If we are not the first technological civilization to have arisen, then technological civilization arose and achieved Singularity long ago, and we are thus astronomically more likely to be in an alien rather than posthuman simulation.
What does this change?
The set of simulation possibilities can be subdivided into PHS (posthuman historical), AHS (alien historical), and AFS (alien future) simulations (as posthuman future simulation is inconsistent). If we discover that we are unlikely to be the first technological Singularity, we should assume AHS and AFS dominate. For reasons beyond this scope, I imagine that the AFS set will outnumber the AHS set.
Historical simulations would aim for historical fidelity, but future simulations would aim for fidelity to a 'what-if' scenario, considering some hypothetical action the alien simulating civilization could take. In this scenario, the first civilization to reach technological Singularity in the galaxy would spread out, gather knowledge about the entire galaxy, and create a massive number of simulations. It would use these in the same way that all universal intelligences do: to consider the future implications of potential actions.
What kinds of actions?
The first-born civilization would presumably encounter many planets that already harbor life in various stages, along with planets that could potentially harbor life. It would use forward simulations to predict the final outcome of future civilizations developing on these worlds. It would then rate them according to some ethical/utilitarian theory (we don't even need to speculate on the criteria), and it would consider and evaluate potential interventions to change the future historical trajectory of that world: removing undesirable future civilizations, pushing other worlds towards desirable future outcomes, and so on.
At the moment its hard to assign apriori weighting to future vs historical simulation possibilities, but the apparent age of the galaxy compared to the relative youth of our sun is a tentative hint that we live in a future simulation, and thus that our history has potentially been altered.