Light waves are never perfectly smooth — they are constantly jittered by quantum ripples. These almost invisible nudges were studied by Nobel laureate Roy Glauber, who laid the foundations of quantum optics. Now physicists have learned to freeze these ripples. They used spectroscopy with flashes lasting just attoseconds — billionths of a billionth of a second. The flash knocks electrons out of atoms before the ripple can even wiggle. The pattern of the ejected electrons essentially photographs the tremor itself. Previous photometry methods struggled with bright light due to shot noise — the chaotic graininess of the photon stream. The attosecond trick bypasses this obstacle.
The method shines particularly with “squeezed” light. In it, quantum uncertainty is redistributed: the tremor in one property is reduced at the expense of amplifying it in another. It’s like pressing a ripple with your finger: the waves get narrower on one side but stretch out on the other. Now scientists can see this squeezing directly. Squeezed light is already used in gravitational wave detectors, making them super-sensitive, and the new approach will simplify its use in quantum computers and communication, where the speed of light is critical.
There are as many attoseconds in one second as there are seconds from the Big Bang to the present day.