Fluid Tests Hint at Concrete Quantum Reality

Re:Fluid Tests Hint at Concrete Quantum Reality by Jach on Monday June 30, 2014 @05:18PM (#7967780)

Have you read Feynman's QED? It's a bit like that, in that it's meant for a layman, but with more algebra. Instead of abstract arrows, EY goes straight to complex numbers. It goes through a basic approach to quantum mechanics (taking diagrams from here for instance: http://www.qi.damtp.cam.ac.uk/node/60) in a modern way and tries to build an intuitive understanding of the subject, especially demolishing a lot of confusions one may have gained through popular media. He then departs from the basic theory to elaborate on why the collapse interpretation is ridiculous and why Many-Worlds makes more sense. You can stop when you get to the Timeless stuff.

You're not really going to find anything ground-breaking, but it may help your intuitions about QM even if you're a physicist. As a chapter from the Aaronson book (http://www.scottaaronson.com/democritus/lec9.html) I linked to in a cousin comment says in the first two paragraphs:

There are two ways to teach quantum mechanics. The first way -- which for most physicists today is still the only way -- follows the historical order in which the ideas were discovered. So, you start with classical mechanics and electrodynamics, solving lots of grueling differential equations at every step. Then you learn about the "blackbody paradox" and various strange experimental results, and the great crisis these things posed for physics. Next you learn a complicated patchwork of ideas that physicists invented between 1900 and 1926 to try to make the crisis go away. Then, if you're lucky, after years of study you finally get around to the central conceptual point: that nature is described not by probabilities (which are always nonnegative), but by numbers called amplitudes that can be positive, negative, or even complex.

Today, in the quantum information age, the fact that all the physicists had to learn quantum this way seems increasingly humorous. For example, I've had experts in quantum field theory -- people who've spent years calculating path integrals of mind-boggling complexity -- ask me to explain the Bell inequality to them. That's like Andrew Wiles asking me to explain the Pythagorean Theorem.

(And on EY himself, just read the million or so words of the Sequences and you'll see he is actually really smart across multiple domains. ;))

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Re:Fluid Tests Hint at Concrete Quantum Reality by acqq on Monday June 30, 2014 @05:25PM (#7967813)

I never claimed that EY isn't smart, only that what he writes is not actually physics.

As much as I remember Feynman's lectures, he introduced the amplitudes very early?

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Re:Fluid Tests Hint at Concrete Quantum Reality by Jach on Monday June 30, 2014 @05:37PM (#7967879)

Fair enough. I agree a large part of it isn't strictly physics, though I think in the beginning it's like the first couple weeks of a high school Mechanics class. Low on math, but you get to do or hear about experiments and how they ought to shape your view of what's going on. (Thinking of masses and acceleration and forces, thinking of complex amplitudes and decoherence.)

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