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

So, it's a bit more subtle. The -1 refers to a phase shift of pi, which is what you happen when reflecting off of e.g. a silver mirror. And interestingly, you only get this if you reflect off of the silvered side, rather than the glass side (I only found this out when googling for this :D ). But for a dielectric mirror (which happens to be symmetric), I think you get a phase shift of pi/2, which corresponds to multiplying by i.

Anywho, I guess it... (read more)

Thanks, that's a good explanation. What do you think is silly about "ra-ra-many-worlds"? The Everett interpretation itself, or just the amount of time EY spends making fun of other interpretations?

Also, my memory may be failing me, but I thought the "mangled worlds" stuff was Nick Bostrom, and not in the QM sequence. Am I thinking of something else?

2Paul Crowley8yIt would be great if you could find a cite for the dielectric mirror observation and comment in the StackExchange thread - thanks!

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?