Superposition isn't the case for a macroscopic object. You already touched on the decoherence issue.
Indeed, I was answering my own musing by raising decoherence in post 430 --- but it was in rebuttal to your sweeping statement:
QM holds in the macro world as well as in the micro-world.
Without qualification, that statement would bring superposition into the macro-world - which would mean the sun would be here, and there, and there --- and the cat, both alive and dead.
Indeed, there are mathematicians out there who subscribe to this notion in the many-worlds theories. I didn't know if you were one of them.
455 posted on 07/10/2003 9:23:05 PM PDT by Alamo-Girl
Oops, I forgot the obligatory link to an article with information on the "many-worlds" theory that results from superposition imposed at the macro level: