In 1989, the renowned physicist John Wheeler, popularizer of the term “black hole,” proposed a radical new way to think about the universe. Quantum particles may shape-shift and disappear, but we can always count on information: the answers revealed when we ask questions through measurements. Wheeler speculated that bits of information — whether something is present or absent, up or down, 0 or 1 — could be the fundamental ingredients of reality. “Every physical quantity, every it, derives its ultimate significance from bits, binary yes-or-no indications,” he wrote in an essay envisioning an “it from bit” cosmos.

In the decades since, various abstract developments have led many physicists to wonder whether Wheeler’s thesis could unlock a profound puzzle: the quantum nature of gravity. Albert Einstein’s general theory of relativity unified gravity with the fabric of space-time, reinterpreting the gravitational force as objects falling along the curved contours of the cosmos. Yet quantum theory struggles to explain these curves in its language of particles and fields. The conflict is on full display in black holes, which deform space so severely that gravity’s more fundamental, quantum nature cannot be ignored.