Maths can describe all manner of natural phenomena with peerless clarity. Now, some mathematicians are wondering if it can succeed where all else has failed by answering the question of how brains light up with experience, known as the “hard problem” of consciousness. It’s a big ask. Experience is, after all, inherently subjective. And sure enough, the first mathematical model of consciousness has generated fierce debate about what, if anything sensible, it can tell us. But as mathematicians finesse their approach, they are confronting an eye-popping possibility that to achieve a precise description of consciousness, we may have to ditch our intuitions and accept that all matter has it, and maybe even the universe as a whole.
