  In the Schr\"odinger-cat gedanken experiment a cat is in a quantum
superposition of two macroscopically distinct states, alive and dead.The
paradoxical interpretation of quantum mechanics is that the cat is not in one
state or the other, alive or dead, immediately prior to its measurement.
Because of this apparent defiance of macroscopic reality, quantum
superpositions of states macroscopically distinct have generated much interest.
Here we address the issue of proving a contradiction with macroscopic reality
objectively, through the testable predictions of quantum mechanics. We consider
the premises of macroscopic reality (that the ``cat'' is either ``dead'' or
``alive'', the measurement indicating which) and macroscopic locality (that
simultaneous measurements some distance away cannot induce the macroscopic
change, ``dead'' to ``alive'' and vice versa, to the ``cat''). The predictions
of quantum mechanics for certain states, generated using states exhibiting
continuous variable entanglement, are shown to be incompatible with the
predictions of all theories based on this dual premise. Our proof is along the
lines of Bell's theorem, but where all relevant measurements give
macroscopically distinct results.
