When Carlo Rovelli's bicycle chain comes off, he calls a bike-shop mechanic, never a particle physicist — even though particle physics technically governs every bolt on the thing. The Italian quantum-gravity theorist uses that fact to swat away one of the loudest arguments in philosophy of mind, in a long essay for Noema titled "There Is No 'Hard Problem Of Consciousness.'" Plenty of natural phenomena resist tidy reduction without being supernatural. That argument was framed by philosopher David Chalmers in 1994. He split consciousness into two puzzles. The "easy" one (his label) covers how neurons produce behavior and memory. The "hard" one asks why any of that brain activity feels like something from the inside — an "explanatory gap" between physical processes and qualia, philosophy jargon for the redness of red, the bite of cold, the raw feels of experience. Rovelli isn't buying it. His objection is recursive: the explanatory gap is a claim about what we'd know if we knew something we don't yet know.…