Haixing Miao

Gravitational waves are ripples in space itself, caused by events like colliding black holes. To hear these ripples, we build giant L-shaped facilities: a laser beam travels down two arms, bounces off mirrors, and returns. If space has been slightly squeezed or stretched, the light arrives with a difference, and we see a signal.

Even Einstein predicted gravitational waves — a trembling of the very fabric of spacetime. Today they are captured by gigantic installations like LIGO, created thanks to Rainer Weiss and Kip Thorne.

Photographing hummingbird wings with an ordinary camera gives a blurry smudge. For a sharp picture, you take many rapid shots from different angles and piece them together: that's how a quantum 'snapshot' is made. In the lab, scientists 'feel' the vibrations of a tiny mirror with a laser beam.

At night on a volcano summit, six telescopes stare at the same speck of light. Each catches its own copy of the wave, and if you combine their signals, you get an image that no single instrument could produce alone. But there's a catch: light captured by different stations cannot simply be added like photographs.