INTD 364: Quantum Reality Spring (3) 2015 Paper #3 - The Quantum Measurement Problem Length: 8-10 pages, double spaced Tuesday May 12, submit to Moodle by 11:59 PM In "classical" physics we assume that a measurement on a system provides information about the state of the system before the measurement was made. In quantum physics it seems that a measurement only gives us definitive information about the state of the system after the measurement was made. Thus quantum measurements provide a very indirect means to understanding how the world works. Moreover, much of the interpretational difficulty with quantum mechanics seems to center around exactly what is meant by making a measurement. For example, the Copenhagen interpretation makes a distinction between the indeterminate (or rather undefined) world of quantum systems and the determinate world of classical measuring devices, but does not clearly define the demarcation between these two coexisting worlds. Thus, in the orthodox interpretation, the act of measurement may be viewed as a miracle, or a mystery, or perhaps simply a muddle, depending on your outlook. Please write a medium length paper that discusses this quantum measurement problem. Be sure to discuss the issues (or perhaps non-issues?) associated with the phrases: "the role of the observer", "the collapse of the wavefunction", and the "creation of reality" in the measurement process. You may want to use Schrodinger's cat and Wigner's friend as illustrations of the problem. You may also want to address the paradox of why we believe quantum theory at all, if we still lack a clear understanding of quantum measurements (which are, of course, the origin of the theory). Finally, you may want to discuss what light (if any) Bell's theorem and Aspect's experiments have to shed on this problem. Please note that I am looking for a well-formulated discussion and not simply a collection of facts here. Your arguments should draw on our three texts and other course reading material as well as including your own views. .