Three Ways to Save Reality

Quantum mechanics works extraordinarily well, yet its standard formulation harbors a deep puzzle: the measurement problem. When no one is looking, particles evolve smoothly according to the Schrödinger equation, but measurements seem to force abrupt, random outcomes, and a fundamental theory of nature shouldn't depend on vague notions like "measurement." In this lecture, David Albert examines three ambitious attempts to resolve this tension while preserving a realistic picture of the physical world. GRW theory introduces spontaneous collapses that eliminate macroscopic superpositions. Everett's many-worlds interpretation keeps the smooth evolution but posits a branching universe, raising thorny questions about probability. Bohm's mechanics restores determinism through hidden variables but faces its own challenges, including nonlocality and the role of configuration space. Albert carefully weighs the advantages and costs of each approach, making vivid the intellectual stakes of one of the deepest problems in the foundations of physics.