An empty resonator isn't truly empty. Even in an absolute vacuum, where not a single photon exists, quantum fluctuations persist. They resemble ripples on water in a dead calm: the surface appears smooth, but molecules keep jittering. Physicists have learned to turn this jitter into real waves.

They built a topological pump — a device that methodically scoops photons out of the vacuum. Instead of a piston, a superconducting qubit (an artificial atom) coupled to a microwave resonator does the work. The qubit performs a precise dance, cycling its parameters through a closed loop. With each step, roughly seven photons are added to the resonator. The tempo of this dance is determined not by the precision of the movements but by the geometry of the cycle itself, like the distance between steps on a spiral staircase. You might stumble, but the height gained remains the same.

In the initial cycles, the pump produced states of light that cannot be described by classical physics. They resemble a coin that lands both heads and tails at once — not because of our ignorance, but by their very nature. Such nonclassical states are building blocks for quantum computers and secure communication. The experiment's authors, using a transmon qubit, observed this operation live for the first time.

The resonator is no longer empty. Light pulses within it, born from nothing, or rather, from the very geometry of the quantum world. And this light behaves not like random flashes but like steady breathing. The same ripples on water, but now they coalesce into a clear wave, surging toward new technologies.