Life is really, really rare, because it takes very long to develop, and it’s possible that Earth got extremely lucky in ways that are essentially unreplicable across the entire accessible universe.
I am not sure how you think this is different from what I said in the post, i.e. that I think most Kolmogorov-simple universes that contain 1 civilization, contain exactly 1 civilization.
All sampling is nonrandom if you bother to overcome your own ignorance about the sampling mechanism.
Physical dependencies, yes. But past and future people don’t have qualitatively more logical dependencies on one another, than multiversal neighbors.
I am not sure how you think this is different from what I said in the post, i.e. that I think most Kolmogorov-simple universes that contain 1 civilization, contain exactly 1 civilization.
The difference is I’m only making a claim about 1 universe, and most importantly, I’m stating that we don’t know enough about what actually happened about life to exclude the possibility that one or more of the Drake equation’s factors is too high, not stating a positive claim that there exists exactly 1 civilization.
More here:
“Hey, for all we know, maybe one or more of the factors in the Drake equation is many orders of magnitude smaller than our best guess; and if it is, then there’s no more Fermi paradox”.
(Also, in an infinite universe, so long as there’s a non-zero probability of civilization arising, especially if it is isotropic like our universe is, then there are technically speaking an infinite number of civilizations.)
All sampling is nonrandom if you bother to overcome your own ignorance about the sampling mechanism.
There are definitely philosophical/mathematical questions on whether any sampling can ever be random even if you could in principle remove all the ignorance that is possible, but the thing that I concretely disagree with is that only logical dependencies are relevant for the doomsday argument, as I’d argue you’d have to take into account all the dependencies avaliable in order to get accurate estimate.
It sounds to me like you’re rejecting anthropic reasoning in full generality. That’s an interesting position, but it’s not a targeted rebuttal to my take here.
Random vs nonrandom is not a Boolean question. “Random” is the null value we can give as an answer to the question “What is our prior?” When we are asking ourselves “What is our prior?”, we cannot sensibly give the answer “Yes, we have a prior”. If we want to give a more detailed answer to the question “What is our prior?” than “random”/”nothing”/”null”/”I don’t know”, it must have particular contents; otherwise it is meaningless.
I was anthropically sampled out of some space, having some shape; that I can say definite things about what this space must be, such as “it had to be able to support conscious processes”, does not obviate that, for many purposes, I was sampled out of a space having higher cardinality than the empty set.
As I learn more and more about the logical structure by which my anthropic position was sampled, it will look less and less “random”. For example, my answer to “How were you were sampled from the space of all possible universes?” is basically, “Well, I know I had to be in a universe that can support conscious processes”. But ask me “Okay, how were you sampled from the space of conscious processes?”, and I’ll say “I don’t know”. It looks random.
“Random” is the null value we can give as an answer to the question “What is our prior?”
I think the word you are looking for here is “equiprobable”.
It’s propper to have equiprobable prior between outcomes of a probability experiment, if you do not have any reason to expect that one is more likely than the other.
It’s ridiculous to have equiprobable prior between states that are not even possible outcomes of the experiment, to the best of your knowledge.
You are not an incorporeal ghost that could’ve inhabited any body throughout human history. You are your parents child. You couldn’t have been born before them or after they are already dead. Thinking otherwise is as silly as throwing a 6 sided die and then expecting to receive any outcome from a 20 sided die.
I was anthropically sampled out of some space
You were not anthropically sampled. You were born as a result of a physical process in a real world that you are trying to approximate as a probability experiment. This process had nothing to do with selecting universes that support conscious processes. This process has already been instantiated in a specific universe and has very limited time frame for your existence.
You will have to ignore all this knowledge and pretend that the process is completely different, without any evidence to back it up, to satisfy the conditions of Doomsday argument.
I am not sure how you think this is different from what I said in the post, i.e. that I think most Kolmogorov-simple universes that contain 1 civilization, contain exactly 1 civilization.
All sampling is nonrandom if you bother to overcome your own ignorance about the sampling mechanism.
Physical dependencies, yes. But past and future people don’t have qualitatively more logical dependencies on one another, than multiversal neighbors.
The difference is I’m only making a claim about 1 universe, and most importantly, I’m stating that we don’t know enough about what actually happened about life to exclude the possibility that one or more of the Drake equation’s factors is too high, not stating a positive claim that there exists exactly 1 civilization.
More here:
(Also, in an infinite universe, so long as there’s a non-zero probability of civilization arising, especially if it is isotropic like our universe is, then there are technically speaking an infinite number of civilizations.)
There are definitely philosophical/mathematical questions on whether any sampling can ever be random even if you could in principle remove all the ignorance that is possible, but the thing that I concretely disagree with is that only logical dependencies are relevant for the doomsday argument, as I’d argue you’d have to take into account all the dependencies avaliable in order to get accurate estimate.
It sounds to me like you’re rejecting anthropic reasoning in full generality. That’s an interesting position, but it’s not a targeted rebuttal to my take here.
And after you bothered to overcome your ignorance, naturally you can’t keep treating the setting as random sampling.
With Doomsday argument, we did bother—to the best of our knowledge we are not a random sample throught all the humans history. So case closed.
Random vs nonrandom is not a Boolean question. “Random” is the null value we can give as an answer to the question “What is our prior?” When we are asking ourselves “What is our prior?”, we cannot sensibly give the answer “Yes, we have a prior”. If we want to give a more detailed answer to the question “What is our prior?” than “random”/”nothing”/”null”/”I don’t know”, it must have particular contents; otherwise it is meaningless.
I was anthropically sampled out of some space, having some shape; that I can say definite things about what this space must be, such as “it had to be able to support conscious processes”, does not obviate that, for many purposes, I was sampled out of a space having higher cardinality than the empty set.
As I learn more and more about the logical structure by which my anthropic position was sampled, it will look less and less “random”. For example, my answer to “How were you were sampled from the space of all possible universes?” is basically, “Well, I know I had to be in a universe that can support conscious processes”. But ask me “Okay, how were you sampled from the space of conscious processes?”, and I’ll say “I don’t know”. It looks random.
I think the word you are looking for here is “equiprobable”.
It’s propper to have equiprobable prior between outcomes of a probability experiment, if you do not have any reason to expect that one is more likely than the other.
It’s ridiculous to have equiprobable prior between states that are not even possible outcomes of the experiment, to the best of your knowledge.
You are not an incorporeal ghost that could’ve inhabited any body throughout human history. You are your parents child. You couldn’t have been born before them or after they are already dead. Thinking otherwise is as silly as throwing a 6 sided die and then expecting to receive any outcome from a 20 sided die.
You were not anthropically sampled. You were born as a result of a physical process in a real world that you are trying to approximate as a probability experiment. This process had nothing to do with selecting universes that support conscious processes. This process has already been instantiated in a specific universe and has very limited time frame for your existence.
You will have to ignore all this knowledge and pretend that the process is completely different, without any evidence to back it up, to satisfy the conditions of Doomsday argument.