Hrm? On a conceptual level, is there more to QM than the Uncertainty Principle and Wave-Particle Duality? DWLM mentions the competing interpretations, but choosing an interpretation is not strictly necessary to understand QM predictions.

For clarity, I consider the double-slit experimental results to be an expression of wave-particle duality.

I will admit that DWLM does a poor job of preventing billiard-ball QM theory ("Of course you can't tell momentum and velocity at the same time. The only way to check is to hit the particle with a proton, and that's going to change the results.").

That's a wrong understanding, but a less wrong understanding than "It's classical physics all the way down."

Which two out of the continuum of world then did you imply, and how did you select them? I don't see any way to select two specific worlds for which "relative thickness" would make sense. You can classify the worlds into "dead/not dead at a certain instance of time" groups whose measures you can then compare, of course. But how would you justify this aggregation with the statement that the worlds, once split, no longer interact? What mysterious process makes this aggregation meaningful? Even if you flinch away from this question, how do you select the time of the measurement? This time is slightly different in different worlds, even if it is predetermined "classically", so there is no clear "splitting begins now" moment.

It gets progressively worse and more hopeless as you dig deeper. How does this splitting propagate in spacetime? How do two spacelike-separated splits merge in just the right way to preserve only the spin-conserving worlds of the EPR experiment and not all possibilities? How do you account for the difference in the proper time between different worlds? Do different worlds share the same spacetime and for how long? Does it mean that they still interact gravitationally (spacetime curvature = gravity). What happens if the spacetime topology of some of the worlds changes, for example by collapsing a neutron star into a black hole? I can imagine that these questions can potentially be answered, but the naive MWI advocated by Eliezer does not deal with any of this.

Moral philosophy is not well developed on LW, but I think it's further than it is elsewhere, and when I look at the pace of developments in philosophy, it looks like it will take decades for everyone else to catch up. Maybe I'm underestimating the quality of mainstream philosophy, though.

All I know is that people who are interested in moral philosophy who haven't been exposed to LW are a lot more confused than those on LW. And that those on LW are more confused than they think they are (hence the OP).

I have a phd in physics (so I have at least some technical skill in this area) and find the QM sequence's argument for many worlds unconvincing. You lead the reader toward a false dichotomy (Copenhagen or many worlds) in order to suggest that the low probability of copenhagen implies many worlds. This ignores a vast array of other interpretations.

Its also the sort of argument that seems very likely to sway someone with an intro class in college (one or two semesters of a Copenhagen based shut-up-and-calculate approach), precisely because having seen Copenhagen and nothing else they 'know just enough to be dangerous', as it were.

For me personally, the quantum sequence threw me into some doubt about the previous sequences I had read. If I have issues with the area I know the most about, how much should I trust the rest? Other's mileage may vary.

For someone who currently has a teacher's-password understanding of physics and would like a more intuitive understanding, without desiring to put in the work to obtain a technical understanding (i.e. learning the math), I would recommend Brian Green's Fabric of the Cosmos, which I feel does for physics (and the history of physics) what An Intuitive Explanation of Bayes Law does for Bayesian probability. It goes through history, starting with Newton and ending with modern day, explaining how the various Big Names came up with their ideas, demonstrates how those ideas can explain reality incrementally better than the previous ideas by using easy-to-envision thought experiments, and also contains a skippable explanation of the mathematic principles behind the new ideas for those who want that, although the book is valuable even without these sections. In this way, it's like a popular science book with an optional textbook component.

It has a couple weaknesses, like taking M-theory seriously, but in general I would say that it accomplishes its goal of imparting an intuitive understanding better than other popular physics books with similar goals, like Hawking's A Brief History of Time, The Universe in a Nutshell, or Green's The Elegant Universe.

Our behaviour and preferences are not consistent and sane enough to be VNM, and we are generally quite confused about what we even want, never mind having reduced it to a utility function.

The thermostat in my room doesn't know what it wants either. However, a utility function models its behaviour pretty well.

Consciousness is the brain's PR department. If it's evasive about what it wants, that could be part of an attempt to manipulate others - e.g. see The Folly of Fools: The Logic of Deceit and Self-Deception in Human Life.

I'm assuming a lot of background in this post that you don't seem to have. Have you read the sequences, specifically the metaethics stuff?

Moral philosophy on LW is decades (at the usual philosophical pace) ahead of what you would learn elsewhere and a lot of the stuff you mentioned is considered solved or obsolete.

right goals

Pardon?

I think you're failing to distinguish between authority one voluntarily submits to (potentially even reserving the right to reverse the decision), e.g., meetup organizer, and authority backed by a monopoly on violence, i.e., the modern conception of government.

Having the right goals is somewhat separate from (my view of) rationality in that rationality is a set of methods oriented towards achieving one's goals and can be applied to any sort of goal, right or wrong as that goal may be. While "selecting the right goals" can itself be a goal that you can use rationality to help with, in principle the methods of rationality can be applied to assist you in any goal.

One might (rightly) point out that applying the methods of rationality to goals that are not desirable may be hazardous for you or for those around you, but this is true for nearly any tool. Increasing one's ability to influence the world will always carry a risk of you influencing the world in a negative direction. Luckily, rationality can be used to help verify that what you're doing is likely to have positive consequences-- it is hence one of very few tools that can actually help the user use it better!