Page 94/95 of "The fabric of the Cosmos"
Greene is refering to some of Einstein's objections to quantum mechanics. Einstein "scaled up" from microscopic objects to the moon to paint what he considered to be an absurdity. In those pages Greene takes no stance on this issue.
The answer of the early QM folks was not that the object (from electrons to galaxies) cease to exist but that the question is not answerable so not something there is any point in asking.
I'll update this if I can find one later.