It has been commonplace to say that quantum effects only become important in the domeain of the very small. But actually ever since superfluidity and the Josephson junction they have been known to be important at the very cold domain too. This is a most ingenious experimental design, and there is every reason to expect it to work.
good point about superfluid helium and Josephson junction (one of a class of cold solid state examples)
the essence of quantum seems not to be that it describes nature at the microscopic level but in how it describes
storing information in a hilbert space, how information is handled
is what makes it a quantum theory or not a quantum theory, or?
I find the identification between quantum and microscopic troubling enough to comment on it sometimes
random thought: ordinary-size black holes are very cold
and, at the same time, a place where macroscopic and microscopic seem ready to converge---where gravity and quantum analysis may make contact. sorry if this is vague, just
a thought your post provoked
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