Prompted by Mitchell Porter, I asked on Physics StackExchange about the accuracy of the physics in the Quantum Physics sequence:

What errors would one learn from Eliezer Yudkowsky's introduction to quantum physics?

Eliezer Yudkowsky wrote an introduction to quantum physics from a strictly realist standpoint. However, he has no qualifications in the subject and it is not his specialty. Does it paint an accurate picture overall? What mistaken ideas about QM might someone who read only this introduction come away with?

I've had some interesting answers so far, including one from a friend that seems to point up a definite error, though AFAICT not a very consequential one: in Configurations and Amplitude, a multiplication factor of *i* is used for the mirrors where -1 is correct.

Physics StackExchange: What errors would one learn from Eliezer Yudkowsky's introduction to quantum physics?

Data point: I only read part of the QM sequence, but that wasn't due to the verbosity as such, but rather because I wasn't familiar with complex numbers and it felt like too much work to learn to use a new math concept and then work my way through the calculations.

It's simpler than you think: you just treat

ias an unknown variable where all you know is thati^2 = -1. Then if you want to, say, multiply together two complex numbers, it's all the algebra you're already familiar with: (a+bi)(c+di) =ac+adi+bci+bdi^2 =ac-bd+ (ad+bc)i. That's it - that's all the complex maths you need to follow the QM sequence.