Speaking of quantum (as we were), I’ve been meaning to link to the recent Scientific American article by Chris Monroe and Dave Wineland on quantum computing with ions. This is a very good explanation of the science involved, but you’d expect nothing else, given that the authors are two of the very best in the business.
What’s especially notable about this article is that either they or the graphic design people at Scientific American came up with a really excellent visual example of quantum indeterminacy and entanglement, using ambiguous cubes. It’s a clever way to illustrate the phenomena involved, and I will be shamelessly stealing it the next time I need to give a lecture about this stuff.
The ambiguous cube has been used by Monroe and Wineland for quite some time (6+ years)- it is a great visual example of both the idea of superposition and the idea of entanglement.
It’s possible for one cube to be one way, the other to be the other way, to my eyes, but there are other, more significant disanalogies between this and a 2-qubit 4-dimensional Hilbert space. Complex superpositions? It seems as if the only superposition that can be presented in the ambiguous cube model is 1/sqrt(2)(|0>+|1>), or is SciAm not presenting the whole scheme? Of course it can be useful to teach by disanalogy.