I suppose the main point you should draw from “Anthropic Blindness” to QI is that:
Quantum Immortality is not a philosophical consequence of MWI, it is an empirical hypothesis with a very low prior (due to complexity).
Death is not special. Assuming you have never gotten a Fedora up to this point, it is consistent to assume that that “Quantum Fedoralessness” is true. That is, if you keep flipping a quantum coin that has a 50% chance of giving you a Fedora, the universe will only have you experience the path that doesn’t give you the Fedora. Since you have never gotten a Fedora yet, you can’t rule this hypothesis out. The silliness of this example demonstrates why we should likewise be skeptical of Quantum Immortality.
If MWI is true, there will be timelines where I survive any risk. This claim is factual and equivalent to MWI, and the only thing that prevents me from regarding it as immortality are questions related to decision theory. If MWI is true, QI has high a priori probability and low associated complexity.
The Fedora case has high complexity and no direct connection to MWI, hence a low a priori probability.
Now for the interesting part: QI becomes distinct from the Fedora case only when the chances are 1 in a trillion.
First example: When 1000 people play Russian roulette and one survives (10 rounds at 0.5), they might think it’s because of QI. (This probability is equivalent to surviving to 100 years old according to the Gompertz law.)
When 1000 people play Quantum Fedora (10 rounds at 0.5), one doesn’t get a Fedora, and they think it’s because they have a special anti-Fedora survival capability. In this case, it’s obvious they’re wrong, and I think this first example is what you’re pointing to.
(I would note that even in this case, one has to update more for QI than for Fedora. In the Fedora case, there will be, say, 1023 copies of me with Fedora after 10 flips of a quantum coin versus 1 copy without Fedora. Thus, I am very unlikely to find myself without a Fedora. This boils down to difficult questions about SSA and SIA and observer selection. Or, in other words: can I treat myself as a random sample, or should I take the fact that I exist without a Fedora as axiomatic? This question arises often in the Doomsday argument, where I treat myself as a random sample despite knowing my date of birth.)
However, the situation is different if one person plays Russian roulette 30 times. In that case, externalization of the experiment becomes impossible: only 8 billion people live on Earth, and there are no known aliens. (This probability is equivalent to surviving to 140 years old according to the Gompertz law.) In this case, even if the entire Earth’s population played Russian roulette, there would be only a 1 percent chance of survival, and the fact of surviving would be surprising. But if QI is true, it isn’t surprising. That is, it’s not surprising to survive to 100 years old, but surviving to 140 is.
Now if I play Fedora roulette 30 times and still have no Fedora, this can be true only in MWI. So if there’s no Fedora after 30 rounds, I get evidence that MWI is true and thus QI is also true. But I am extremely unlikely to find myself in such a situation.
I suppose the main point you should draw from “Anthropic Blindness” to QI is that:
Quantum Immortality is not a philosophical consequence of MWI, it is an empirical hypothesis with a very low prior (due to complexity).
Death is not special. Assuming you have never gotten a Fedora up to this point, it is consistent to assume that that “Quantum Fedoralessness” is true. That is, if you keep flipping a quantum coin that has a 50% chance of giving you a Fedora, the universe will only have you experience the path that doesn’t give you the Fedora. Since you have never gotten a Fedora yet, you can’t rule this hypothesis out. The silliness of this example demonstrates why we should likewise be skeptical of Quantum Immortality.
It is not clear for me why you call
If MWI is true, there will be timelines where I survive any risk. This claim is factual and equivalent to MWI, and the only thing that prevents me from regarding it as immortality are questions related to decision theory. If MWI is true, QI has high a priori probability and low associated complexity.
The Fedora case has high complexity and no direct connection to MWI, hence a low a priori probability.
Now for the interesting part: QI becomes distinct from the Fedora case only when the chances are 1 in a trillion.
First example:
When 1000 people play Russian roulette and one survives (10 rounds at 0.5), they might think it’s because of QI. (This probability is equivalent to surviving to 100 years old according to the Gompertz law.)
When 1000 people play Quantum Fedora (10 rounds at 0.5), one doesn’t get a Fedora, and they think it’s because they have a special anti-Fedora survival capability. In this case, it’s obvious they’re wrong, and I think this first example is what you’re pointing to.
(I would note that even in this case, one has to update more for QI than for Fedora. In the Fedora case, there will be, say, 1023 copies of me with Fedora after 10 flips of a quantum coin versus 1 copy without Fedora. Thus, I am very unlikely to find myself without a Fedora. This boils down to difficult questions about SSA and SIA and observer selection. Or, in other words: can I treat myself as a random sample, or should I take the fact that I exist without a Fedora as axiomatic? This question arises often in the Doomsday argument, where I treat myself as a random sample despite knowing my date of birth.)
However, the situation is different if one person plays Russian roulette 30 times. In that case, externalization of the experiment becomes impossible: only 8 billion people live on Earth, and there are no known aliens. (This probability is equivalent to surviving to 140 years old according to the Gompertz law.) In this case, even if the entire Earth’s population played Russian roulette, there would be only a 1 percent chance of survival, and the fact of surviving would be surprising. But if QI is true, it isn’t surprising. That is, it’s not surprising to survive to 100 years old, but surviving to 140 is.
Now if I play Fedora roulette 30 times and still have no Fedora, this can be true only in MWI. So if there’s no Fedora after 30 rounds, I get evidence that MWI is true and thus QI is also true. But I am extremely unlikely to find myself in such a situation.