Three acts.One remnant.
The waveform is not a metaphor. It is a chronology written in strain. Drag the playhead. Watch the orbit fail, and then watch the hole become quiet.
01
Inspiral
Two black holes orbit. Gravitational waves carry energy and angular momentum away. The orbit decays. The frequency rises. A chirp.
- Inspiral
- Merger
- Ringdown
Amplitude and time are not to scale. The tone is a pedagogical chirp, frequency-scaled into hearing, as LIGO does for public audio. Not GW231029. The three names are the standard IMR decomposition.
After ringdown, the no-hair theorems say the remnant is described by mass and spin. Charge, in astrophysics, is usually negligible.
Numerical relativity supplies the merger; black-hole perturbation theory supplies the ringdown tones (quasinormal modes). Matching them to the inspiral is how a template is born. If the ringdown overtones fit Kerr, the remnant is behaving like a rotating black hole.