https://phys.org/news/2018-06-harmonic-oscillator-classical-like-state-nonclassical.html

"Einstein's intriguing and much debated question 'Is the moon there when nobody looks at it?' concerns the everyday notion of macrorealism, which lies at the core of the classical worldview," Home told Phys.org. "To put it simply, macrorealism means that, at any instant, a system is in a definite state having definite properties, irrespective of any observation/measurement.

"In this context, our work opens up a novel direction for testing macrorealism by showing that the quantum mechanical violation of macrorealism is testable for a system like a harmonic oscillator, which has a well-defined classical description and is initially in a state which is the most classical-like of all quantum states, the harmonic oscillator coherent state."