What Is Real?: The Unfinished Quest for the Meaning of Quantum Physics

by Adam Becker

Suddenly, entanglement and Bell’s theorem weren’t just concerns for a handful of physicists and philosophers in an abstruse and neglected corner of science. Practical questions of computing technology and cryptography were at stake, and naturally, governments and militaries took a fierce interest in the subject. Mastering control of entanglement, decoherence, and other phenomena first described by researchers in quantum foundations was potentially big business—and the race to build a quantum computer was on. The funding floodgates opened. Within a decade of Shor’s breakthrough, the Department of Defense was funding a $20 million initiative in quantum information. By 2016, multiple US government agencies, both military and civilian, were funding quantum information technology; the EU was funding €1 billion of research and development in the subject; and China was testing a quantum communication satellite. Private corporations, like Google and Microsoft, were also doing work in this field. In short, quantum information processing was no longer a part of quantum foundations—it had spun off and become its own billion-dollar industry. But little of this money was going to quantum foundations. The flood of new grants were almost entirely for developing practical things like building quantum computers themselves, not for new approaches to the measurement problem. Quantum foundations had borne this new fruit, it had proven it wasn’t useless, but the advances in quantum information...