In physics, some hypotheses can take more than a lifetime to confirm—as happened in 2019, when researchers saw the first image of a black hole, a cosmological phenomenon whose existence was theorized by Albert Einstein a full century before but never observed directly. Other ideas in physics have endured decades of debate, without resolution or further clarity. In this issue, reporter Davide Castelvecchi profiles the fascinating history of a landmark experiment from 1922 that recorded the quantum spin of an elementary particle, the interpretation of which is still ongoing (see “Hundred Years Ago a Quantum Experiment Explained Why We Don’t Fall through Our Chairs”).
Elsewhere in this issue, columnist John Horgan contemplates what a radical new quantum theory means for our perception of reality (see “Does Quantum Mechanics Reveal That Life Is but a Dream?”). He writes that quantum researchers share a notable trait with artists “who try to turn the chaos of things into a meaningful narrative.” I would take his idea further and say that finding sense among life’s challenges is an inherent part of all human experience.