The table of different sampling assumptions in anthropics

5MSRayne

4Yoav Ravid

2avturchin

3Tristan Cook

2avturchin

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It seems to me that one ought to reason in such a way as to maximize expected utility. That is my answer to the meta-problem, but I have no idea what to think about sampling assumptions. To be honest anthropics seems very mysterious and superstitious to me and I struggle to understand it at all.

Thanks for putting this together! Lots of ideas I hadn't seen before.

As for the meta-level problem, I agree with MSRayne to do the thing that maximises EU which leads me to the ADT/UDT approach. This assumes we can have some non-anthropic prior, which seems reasonable to me.

I think that the problem (one of them) here is that my utility function may include some indexical preferences. Like "I want to be in simulation". Or "I don't want to be a Boltzmann brain". In that case, I return to the need of updating, as I again have to take into account my indexicals.

Also, it allows the existence of "utility monster": that I should act as if I will have the biggest possible impact on the future of humanity, even if prior odds of that is small.

“…. anthropic reasoning: complicated, error-prone,looks a bit magical but once you start getting real evidence muchof it becomes irrelevant.”SandbergThe meta-meta-problem of anthropics is how to find the right way to choose between principles of selecting the correct sampling assumptions, but before we get there, let's first list all known and even unknown sampling assumptions.

The full list, including some related ideas, has 38 items (google doc here, text version below).

I suggest several possibly new assumptions for the sake of completeness of the list, but it doesn’t mean that I endorse them (like “intensity sampling” and “observer-moment-size sampling”) and it doesn’t mean that they were never suggested before.

## 1. Classical assumptions based on the difference between possible and real observers.

Self-sampling assumption.I am randomly selected from allactuallyexisting observers of my reference class.SSSA. Strong self-sampling assumption. The same as SSA, but the selection is between the observer-moments (OM).Super-strong self-sampling assumption: I am selected from all minds weighted by their intelligence.Variant: I am selected from all observer-moments proportional to their “size”..SSA is true for every reference class. I am randomly selected from each and every reference class to which I belong if they are mutually independent and all their members consist of qualified observers.Self-indication assumption.“We should give higher probability to hypotheses that contain more observers, other things being equal”, Tomasic. Classical definition: “I am randomly selected from all possible observers”.youspecifically, without needing to define observers in general”, Tomasik.## 2. Selection only in some tempo-spatial aspects.

Physics sampling assumptionby Tomasik: how often given observation will appear in different universes. Highest spatial density is favoured. I am likely to be in the universes which have a higherdensityof observers like me.Big CrunchoverHeat Deathas it has a smaller total volume.solipsismas it gives the highest density of observers.Now-time selection principle. I am randomly selected from all observers, who livenow, but not in thepastor in thefuture. A variant: I am selected from “now and the past” (depends on the model of time, like theblock model of time).earliest observer in our civilizationwho learns something about anthropics (which seems to be false).Anti-youngness paradox: I am now in the last moment of the universe’s existence (e.g. just before False Vacuum decay) as the number of branches is maximal at that moment. Quantum immortality seems to balance the problem, as I will constantly miraculously survive the end of the universe.numberof the branches, but the totalmeasureof all branches as constant, then the measure declines extremely quickly for any given branch and I must be very early.## 3. The role of the observers’ self-reflection in sampling.

qualified observers: the ones who are thinking about anthropics.Wider: Or at leastcanthink.: Thinner: Or are thinkingexactlylike me.very soon, as the qualified observers appeared only recently(around 1970) in our civilization’s history and the number of them is growing.## 4. Decision-theoretic approaches

Functional decision theory:I am randomly selected from all functionally similar lines of thought. (This is my interpretation of FDT, could be wrong –AT)Anthropic decision theory(a variant of Updateless Decision Theory). I should reason in a way which increases global utility, without updating on my local position.Full non-indexical conditioning.Chances of my appearance under different theories are: “P(theory of the universe | I exist) ∝ P(I exist | theory of the universe) * P(theory of the universe", Tomasic).## 5. Computational approach.

## 6. The difference between subjective and objective probabilities

Subjective probabilitiesare completely different from objective and could be manipulated by the order of creating of copies.## 7. Other similar principles

Unification theory of identity(Tomasic). I am represented by all my copies simultaneously, therefore, no selection happens and no need for the selection assumption.## 8. “Measure” as a probability of being a given observer

measureis proportional to the number of microstates which represent one macro state (similar to entropy).Qualia-selection. I am randomly selected only from those who:Causal connectedness. Selection should be only from a causally-connected region of the universe.Energy-based selection.I am selected based on the energy used for computations; I am unlikely to be a Boltzmann brain, as they “use” minimal energy.Intensity-based selection. My experience is in the middle of the set of all minds ordered by theintensityof pain and pleasure.## 9. Related ideas

Universes’ sampling.Replicating (via black holes) fecund universes from evo-devo theory.Panpsychism. All physical processes and computations have qualia and I am randomly selected from all of them.Gaia hypothesis(Quantum immortality-in the-past favors effective survivors).willeventually get a “measure burst” in the future.unescapable prophecies)are possible, I am likely stack in one of them, as it the significantly increases measure.## The meta-level problem of choosing right assumption

On the meta-level, there are several principles how to choose between three dozen of sampling assumptions from the table:

## The meta-meta problem

The meta-meta-problem of anthropics is how to find the right way to choose between the listed above principles of selecting the correct sampling assumptions. This meta-meta problem is more about general epistemic considerations than about some ideas related to anthropics. The possible ways of choice are based on utility, or on averaging, or on logical proof, or on finding inconsistencies, or some form of a prediction market.

Personally, I think that most of the listed above sampling assumptions are working simultaneously, with some adjustments depending on the local situation and the question asked. If I have to choose, I will multiply predictions on my credence in different alternatives, which is even. I will give 2/5 in Sleeping Beauty as an average between halfers and thirders, if the measurement way is not defined.