If you think you've learned quantum mechanics from it, you're a fool. If you think you've learned enough about quantum mechanics to be justified as a physical realist, you're correct. Oodles of things are left out, and many others simplified, but there are few things that are actually wrong, and they have little impact.

in Configurations and Amplitude, a multiplication factor of i is used for the mirrors where -1 is correct.

The main question is relative phase, and the transmitted portion can have an arbitrary phase shift, by selecting the thickness of t... (read more)

This might be a good time for me to respond to one of your earlier comments.

I was under the impression that it's a big mystery what complex numbers are doing (i.e., what is their physical function, what do they mean) in QM. I was under the impression that this is a matter of much speculative debate. Yet when I said that, I was downvoted a lot, and you implicitly alleged that I was obviously ignorant or misinformed in some way, and that we have a perfectly good understanding of what complex numbers are doing in the Dirac equation. Could you or someone please give me some background info, so that I can better understand the current state of understanding of the role of complex numbers in QM?

9shminux8yGot one of those, too, and my opinion is basically the same, except for the MWI advocacy, which takes away from the QM sequence's usefulness (advocacy always does). In a nutshell: * There are no particles, only fields (described by amplitudes evolving in space, time and other coordinates). Particles/waves show up as pattern matching to classical concepts, depending on the experiments. * The measurement step (the Born rule) is still mysterious (i.e. an open problem in Physics), despite what anyone, including EY, says. Hence the dozens of "interpretations".

How accurate is the quantum physics sequence?

by Paul Crowley 1 min read17th Apr 201268 comments

49


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?