Computing With Quantum Cats

Author: John Gribbin

This book was better than Quantum Supremacy. Got more detailed into how quantum computers work. It spent more time to my liking giving biographies of everyone who remotely influenced the tech. Including a painfully long one about Turing, which I was already familiar with his story from a) The Imitation Game movie, b) Simon Singh’s The Code Book. But some of them were useful, like Feynman, Einstein.

The whole topic of multiple universes with respect to quantum is pretty interesting. I feel the urge to write it off, but there was an interesting section in the book talking about it:

David Deutsch’s famous rhetorical question from his 1997 book The Fabric of Reality, that goes something like:

“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?”