Schrödinger's cat comes closer: Nature

Ivan Seeking
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Now a team of physicists has published the recipe for making a large object - not cat-sized, but certainly bacterium-sized - in such a quantum quandary1. A tiny mirror, they propose, can be in two places at once... William Marshall of the University of Oxford and his coworkers outline a scheme for evading decoherence to achieve a quantum superposition of states in an object with around a hundred trillion atoms. This is about a billion times larger than anything demonstrated previously.

http://www.nature.com/nsu/030929/030929-3.html
 
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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.
 
Originally posted by selfAdjoint
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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Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
Is it possible, and fruitful, to use certain conceptual and technical tools from effective field theory (coarse-graining/integrating-out, power-counting, matching, RG) to think about the relationship between the fundamental (quantum) and the emergent (classical), both to account for the quasi-autonomy of the classical level and to quantify residual quantum corrections? By “emergent,” I mean the following: after integrating out fast/irrelevant quantum degrees of freedom (high-energy modes...
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