No moon there - from Nature Physics

"An experiment reveals that micrometre-sized superconducting circuits follow the laws of quantum mechanics, and thus defy common experience of how macroscopic objects should behave. ... ' I like to think that the moon is there even if I don’t look at it', Albert Einstein once remarked. He objected to the notion that truly macroscopic objects might behave according to the laws of quantum mechanics ... Anthony Leggett and Anupam Garg provided... a quantitative test to determine whether a macroscopic object would indeed at all times be in one of its distinct two states or whether quantum mechanics would prevail. The example they used was that of a superconducting ring generating a measurable magnetic flux .... Using a superconducting circuit similar to the one proposed originally, they show that the behaviour of their ‘macroscopic object’ clearly follows the predictions of quantum mechanics. The moon — a small moon, admittedly — is not there."

Johan E. Mooij
nature physics | VOL 6 | JUNE 2010 | www.nature.com/naturephysics