A regular laser is like a choir where everyone sings their own part — the sound is loud, but with inevitable roughness. In the new quantum laser, the singers hear each other and harmonize their voices. This coordination reduces entropy (the level of chaos) and suppresses quantum noise — the inevitable quivering of light at the microscopic level. The result is squeezed light: uncertainty is reduced in one property (like timing precision) at the expense of another (intensity). And like any light, it travels at the speed of light.

This 'sharp-eyed' quality already aids spectroscopy — decoding the composition of substances from their glow. But the most unexpected twist: squeezed light is used in the antennas of gravitational wave observatories, where it catches space-time ripples thousands of times thinner than an atom. Charles Townes, who invented the first laser, could not have imagined such quantum coordination, while the followers of Roy Glauber are bringing it to life.