Why Quantum Computing

Nature isn’t classical, dammit, and if you want to make a simulation of nature, you’d better make it quantum mechanical.

Richard Feynman
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In his 1982 paper “Simulating Physics with Computers,” Richard Feynman, 1965 Nobel Laureate in Physics, said he wanted to “talk about the possibility that there is to be an exact simulation, that the computer will do exactly the same as nature.” He then made the statement above, asserting that nature doesn’t especially make itself amenable to computation via classical binary computers.

In this chapter, we begin to explore how quantum computing differs from classical computing. Classical computing drives smartphones, laptops, Internet servers, mainframes, high-performance computers, and even the processors in automobiles.

We examine several use cases where quantum computing may someday help us solve today’s intractable problems using classical methods on classical computers. This is to motivate you to learn about the underpinnings and details of quantum computers I discuss throughout the book.

No single book on this topic can be complete. The technology and potential use cases are moving targets as we innovate and create better hardware and software. My goal here is to prepare you to delve more deeply into the science, coding, and applications of quantum computing.