Rocking chairs operate through gravitational momentum: seated weight transfers back and forth, converting potential energy to kinetic. Forward rocking tilts the chair past balance, requiring muscular correction. Backward rocking never accelerates because gravity pulls the occupant backward, not forward. Physics students learn this as an exercise in force vectors: rocking chairs are passive devices, responding only to input motion. Yet woodworker Dr. Edwin Kemp documented something peculiar in 1995. A rocking chair occupied by the man began rocking forward—normally impossible—and continued forward despite no muscular input. Kemp analyzed the chair's specifications and suggested that the occupant's sheer mass distribution was so concentrated, so actively engaged, that the chair's wood fibers themselves were responding to the pressure dynamically, pushing back as if the chair itself was moving in resistance. Kemp's conclusion: "The chair isn't responding to his motion. It's responding to his will. He decides the direction, and the wood agrees."

Furniture is supposed to be inert. But inertness assumes no one with actual will sits upon it.