The idea of acausal multiverse wide cooperation make sense even if at least one of many ideas why universe is (almost) infinitely large has significant probability. Tegmark listed 4 reasons for multiverse, I find that actually there are around 10.
Anyway, I think that everettian multiverse is more than just “interpretation”, and you are right that we shouldn’t based our policy on “interpretations”. The same way, “anthropic principle” is not a just “principle”—we use to call it such way, but it is more than just a random principle of unknown epistemic status—it is a idea about conditional probability of past events and could be presented without being called “principle”.
In other words, “everettian interpretation” is not “interpretation”, but a physical theory. Could it be tested or not is another question, some suggestions exist, but debatable, like “quantum suicide test” or “quantum bomb testing”.
I am one of those who considers Tegmark’s hierarchy a steaming pile of BS that has nothing to do with physics or reality. So I automatically discount any reasoning based on this. The many-worlds direction is a natural way to try to extrapolate quantum mechanics, but so far it has not produced anything consistent, and it is in direct conflict with general relativity, since all those multiple worlds share the same spacetime, yet produce no obvious gravitational effects despite being macroscopic, if not detectable by other means because of the decoherence. So for now it is just a convenient tool for musing about possible worlds while pretending that they are real. That is how Eliezer uses it, anyway. And the flock of his followers who learned about QM from his sequence on the topic.
The anthropic principle is a different beast, and I agree that it has some usefulness, though not nearly as much as its proponents claim, mainly because you cannot usefully talk about probabilities without specifying a probability distribution. But that’s a different topic.
I understand your position: EY ignores many other interesting interpretations of QM, like retrocausality, and if you goes deeper in the field, his position may seem oversimplified.
However, it is not equal to the claim that universe is finite in space and in time. Even if some form of infinity (or very largeness) is possible, like cyclic universe, it creates possibility of existence of very large number of civilizations in casually disconnected regions. This idea may need additional analysis without simple linking Tegmark.
The idea of acausal multiverse wide cooperation make sense even if at least one of many ideas why universe is (almost) infinitely large has significant probability. Tegmark listed 4 reasons for multiverse, I find that actually there are around 10.
Anyway, I think that everettian multiverse is more than just “interpretation”, and you are right that we shouldn’t based our policy on “interpretations”. The same way, “anthropic principle” is not a just “principle”—we use to call it such way, but it is more than just a random principle of unknown epistemic status—it is a idea about conditional probability of past events and could be presented without being called “principle”.
In other words, “everettian interpretation” is not “interpretation”, but a physical theory. Could it be tested or not is another question, some suggestions exist, but debatable, like “quantum suicide test” or “quantum bomb testing”.
I am one of those who considers Tegmark’s hierarchy a steaming pile of BS that has nothing to do with physics or reality. So I automatically discount any reasoning based on this. The many-worlds direction is a natural way to try to extrapolate quantum mechanics, but so far it has not produced anything consistent, and it is in direct conflict with general relativity, since all those multiple worlds share the same spacetime, yet produce no obvious gravitational effects despite being macroscopic, if not detectable by other means because of the decoherence. So for now it is just a convenient tool for musing about possible worlds while pretending that they are real. That is how Eliezer uses it, anyway. And the flock of his followers who learned about QM from his sequence on the topic.
The anthropic principle is a different beast, and I agree that it has some usefulness, though not nearly as much as its proponents claim, mainly because you cannot usefully talk about probabilities without specifying a probability distribution. But that’s a different topic.
I understand your position: EY ignores many other interesting interpretations of QM, like retrocausality, and if you goes deeper in the field, his position may seem oversimplified.
However, it is not equal to the claim that universe is finite in space and in time. Even if some form of infinity (or very largeness) is possible, like cyclic universe, it creates possibility of existence of very large number of civilizations in casually disconnected regions. This idea may need additional analysis without simple linking Tegmark.