David Deutsch, in his book "The Fabric of Reality", gives example of a problem that is presumably easily solvable by the quantum computer. On the other hand, he explains that the total number of particles in the universe is smaller than number of computations that will take place. The question that he poses is where the problem was actually solved? His answer is that there parallel universes, and the computation is performed in these universes. He also stipulates that the "weird" quantum behavior of particles, such as spooky action at a distance, all could be explained by the multiverse. What is your opinion about the multiverse and potential of quantum computers to solve quantum physics problems?
"Logically, the possibility of complex quantum computations adds nothing to a case [for the Many Worlds Interpretation] that is already unanswerable. But it does add psychological impact. With Shor’s algorithm, the argument has been writ very large. To those who still cling to a single-universe world-view, I issue this challenge: explain how Shor’s algorithm works. I do not merely mean predict that it will work, which is merely a matter of solving a few uncontroversial equations. I mean provide an explanation. When Shor’s algorithm has factorized a number, using 10^500 or so times the computational resources that can be seen to be present, where was the number factorized? There are only about 10^80 atoms in the entire visible universe, an utterly minuscule number compared with 10^500. So if the visible universe were the extent of physical reality, physical reality would not even remotely contain the resources required to factorize such a large number. Who did factorize it, then? How, and where, was the computation performed?"
David Deutsch, in his book "The Fabric of Reality", gives example of a problem that is presumably easily solvable by the quantum computer. On the other hand, he explains that the total number of particles in the universe is smaller than number of computations that will take place. The question that he poses is where the problem was actually solved? His answer is that there parallel universes, and the computation is performed in these universes. He also stipulates that the "weird" quantum behavior of particles, such as spooky action at a distance, all could be explained by the multiverse. What is your opinion about the multiverse and potential of quantum computers to solve quantum physics problems?