Quantum superposition of distinct macroscopic states. Peer review information Nature Physics thanks Stephen Adler and the other, anonymous, reviewer s for their contribution to the peer review of this work. Copy to clipboard. This is also true in probability, when the statistics of two random variables are correlated. Provided by the Springer Nature SharedIt content-sharing initiative. Researchers are particularly keen to examine one idea about how quantum becomes classical. Skip to main content Thank you for visiting nature.