Luciano Petruzziello

Quantum objects live in a world of superpositions — being here and there at the same time, with one spin and another. But as soon as they gain enough mass, this magic fades. Roger Penrose suggested that gravity itself is to blame.

Two spinning tops whirl in an invisible dance, tied together by a thread of spacetime. One of them, massive and rotating, is in a superposition of two opposite directions of rotation. The second, a light test particle, moves in a circle around the first. Their motions intertwine, generating quantum entanglement through the gravitational field.