Einstein's Final Prediction
In 1916, Albert Einstein predicted that accelerating masses would produce ripples in spacetime itself — gravitational waves. He thought they would never be detected: the effect is unimaginably tiny. A century later, on September 14, 2015, LIGO detected the first gravitational wave from two black holes merging 1.3 billion light-years away. The signal stretched LIGO's 4-kilometer arms by less than one ten-thousandth of a proton's diameter.
The Chirp
As two compact objects spiral toward each other, they orbit faster and faster, emitting gravitational waves of increasing frequency and amplitude. This produces a characteristic 'chirp' — a signal that sweeps from low to high pitch in the final seconds before merger. The simulation above visualizes this chirp and the spacetime distortion it produces. Adjust the masses to hear how the signal changes.
The Most Energetic Events
The first detected merger (GW150914) converted about 3 solar masses into pure gravitational wave energy in 0.2 seconds. For that brief moment, the merger radiated more power than all the stars in the observable universe combined. The simulation computes the chirp mass, frequency evolution, and strain amplitude for any binary system you configure.
A New Window on the Universe
Gravitational wave astronomy has opened an entirely new way to observe the cosmos. Unlike light, gravitational waves pass through matter unimpeded. They reveal phenomena invisible to telescopes: black hole mergers, neutron star collisions, and possibly cosmic strings or phase transitions in the early universe. Each new detection refines our understanding of gravity, matter, and the structure of spacetime.