This doesn’t feel like a track record claim to me. Nothing has changed since Eliezer wrote that; it reads as reasonably now as it did then; and we have nothing objective against which to evaluate it.
I broadly agree with Eliezer that (i) collapse seems unlikely, (ii) if the world is governed by QM as we understand it, the whole state is probably as “real” as we are, (iii) there seems to be nothing to favor the alternative interpretations other than those that make fewer claims and are therefore more robust to unknown-unknowns. So if anything I’d be inclined to give him a bit of credit on this one, given that it seems to have held up fine for readers who know much more about quantum mechanics than he did when writing the sequence.
The main way the sequence felt misleading was by moderately overstating how contrarian this take was. For example, near the end of my PhD I was talking with Scott Aaronson and my advisor Umesh Vazirani, who I considered not-very-sympathetic to many worlds. When asked why, my recollection of his objection was “What are these ‘worlds’ that people are talking about? There’s just the state.” That is, the whole issue turned on a (reasonable) semantic objection.
However, I do think Eliezer is right that in some parts of physics collapse is still taken very seriously and there are more-than-semantic disagreements. For example, I was pretty surprised by David Griffiths’ discussion of collapse in the afterword of his textbook (pdf) during undergrad. I think that Eliezer is probably right that some of these are coming from a pretty confused place. I think the actual situation with respect to consensus is a bit muddled, and e.g. I would be fairly surprised if Eliezer was able to make a better prediction about the result of any possible experiment than the physics community based on his confidence in many-worlds. But I also think that a naive-Paul perspective of “no way anyone is as confused as Eliezer is saying” would have been equally-unreasonable.
I agree that Eliezer is overconfident about the existence of the part of the wavefunction we never see. If we are deeply wrong about physics, then I think this could go either way. And it still seems quite plausible that we are deeply wrong about physics in one way or another (even if not in any particular way). So I think it’s wrong to compare many-worlds to heliocentrism (as Eliezer has done). Heliocentrism is extraordinarily likely even if we are completely wrong about physics—direct observation of the solar system really is a much stronger form of evidence than a priori reasoning about the existence of other worlds. Similarly, I think it’s wrong to compare many-worlds to a particular arbitrary violation of conservation of energy when top quarks collide, rather than something more like “there is a subtle way in which our thinking about conservation of energy is mistaken and the concept either doesn’t apply or is only approximately true.” (It sounds reasonable to compare it to the claim that spinning black holes obey conservation of angular momentum, at least if you don’t yet made any astronomical observations that back up that claim.)
My understanding is this is the basic substance of Eliezer’s disagreement with Scott Aaronson. My vague understanding of Scott’s view (from one conversation with Scott and Eliezer about this ~10 years ago) is roughly “Many worlds is a strong prediction of our existing theories which is intuitively wild and mostly-experimentally-unconfirmed. Probably true, and would be ~the most interesting physics result ever if false, but still seems good to test and you shouldn’t be as confident as you are about heliocentrism.”
When I said it was relevant to his track record as a public intellectual, I was referring to his tendency to make dramatic and overconfident pronouncements (which Ben mentioned in the parent comment). I wasn’t intending to imply that the debate around QM had been settled or that new information had come out. I do think that even at the time Eliezer’s positions on both MWI and why people disagreed with him on it were overconfident though.
I think you’re right that my comment gave too little credit to Eliezer, and possibly misleadingly implied that Eliezer is the only one who holds some kind of extreme MWI or anti-collapse view or that such views are not or cannot be reasonable (especially anti-collapse). I said that MWI is a leading candidate but that’s still probably underselling how many super pro-MWI positions there are. I expanded on this in another comment.
Your story of Eliezer comparing MWI to heliocentrism is a central example of what I’m talking about. It is not that his underlying position is wrong or even unlikely, but that he is significantly overconfident.
I think this is relevant information for people trying to understand Eliezer’s recent writings.
To be clear, I don’t think it’s a particularly important example, and there is a lot of other more important information than whether Eliezer overestimated the case for MWI to some degree while also displaying impressive understanding of physics and possibly/probably being right about MWI.
This doesn’t feel like a track record claim to me. Nothing has changed since Eliezer wrote that; it reads as reasonably now as it did then; and we have nothing objective against which to evaluate it.
I broadly agree with Eliezer that (i) collapse seems unlikely, (ii) if the world is governed by QM as we understand it, the whole state is probably as “real” as we are, (iii) there seems to be nothing to favor the alternative interpretations other than those that make fewer claims and are therefore more robust to unknown-unknowns. So if anything I’d be inclined to give him a bit of credit on this one, given that it seems to have held up fine for readers who know much more about quantum mechanics than he did when writing the sequence.
The main way the sequence felt misleading was by moderately overstating how contrarian this take was. For example, near the end of my PhD I was talking with Scott Aaronson and my advisor Umesh Vazirani, who I considered not-very-sympathetic to many worlds. When asked why, my recollection of his objection was “What are these ‘worlds’ that people are talking about? There’s just the state.” That is, the whole issue turned on a (reasonable) semantic objection.
However, I do think Eliezer is right that in some parts of physics collapse is still taken very seriously and there are more-than-semantic disagreements. For example, I was pretty surprised by David Griffiths’ discussion of collapse in the afterword of his textbook (pdf) during undergrad. I think that Eliezer is probably right that some of these are coming from a pretty confused place. I think the actual situation with respect to consensus is a bit muddled, and e.g. I would be fairly surprised if Eliezer was able to make a better prediction about the result of any possible experiment than the physics community based on his confidence in many-worlds. But I also think that a naive-Paul perspective of “no way anyone is as confused as Eliezer is saying” would have been equally-unreasonable.
I agree that Eliezer is overconfident about the existence of the part of the wavefunction we never see. If we are deeply wrong about physics, then I think this could go either way. And it still seems quite plausible that we are deeply wrong about physics in one way or another (even if not in any particular way). So I think it’s wrong to compare many-worlds to heliocentrism (as Eliezer has done). Heliocentrism is extraordinarily likely even if we are completely wrong about physics—direct observation of the solar system really is a much stronger form of evidence than a priori reasoning about the existence of other worlds. Similarly, I think it’s wrong to compare many-worlds to a particular arbitrary violation of conservation of energy when top quarks collide, rather than something more like “there is a subtle way in which our thinking about conservation of energy is mistaken and the concept either doesn’t apply or is only approximately true.” (It sounds reasonable to compare it to the claim that spinning black holes obey conservation of angular momentum, at least if you don’t yet made any astronomical observations that back up that claim.)
My understanding is this is the basic substance of Eliezer’s disagreement with Scott Aaronson. My vague understanding of Scott’s view (from one conversation with Scott and Eliezer about this ~10 years ago) is roughly “Many worlds is a strong prediction of our existing theories which is intuitively wild and mostly-experimentally-unconfirmed. Probably true, and would be ~the most interesting physics result ever if false, but still seems good to test and you shouldn’t be as confident as you are about heliocentrism.”
When I said it was relevant to his track record as a public intellectual, I was referring to his tendency to make dramatic and overconfident pronouncements (which Ben mentioned in the parent comment). I wasn’t intending to imply that the debate around QM had been settled or that new information had come out. I do think that even at the time Eliezer’s positions on both MWI and why people disagreed with him on it were overconfident though.
I think you’re right that my comment gave too little credit to Eliezer, and possibly misleadingly implied that Eliezer is the only one who holds some kind of extreme MWI or anti-collapse view or that such views are not or cannot be reasonable (especially anti-collapse). I said that MWI is a leading candidate but that’s still probably underselling how many super pro-MWI positions there are. I expanded on this in another comment.
Your story of Eliezer comparing MWI to heliocentrism is a central example of what I’m talking about. It is not that his underlying position is wrong or even unlikely, but that he is significantly overconfident.
I think this is relevant information for people trying to understand Eliezer’s recent writings.
To be clear, I don’t think it’s a particularly important example, and there is a lot of other more important information than whether Eliezer overestimated the case for MWI to some degree while also displaying impressive understanding of physics and possibly/probably being right about MWI.