Two dead suns circle in an eternal dance. Their orbit is a perfect metronome, keeping time with the accuracy of atomic clocks. But even dead stars can tremble. Gravitational waves from such pairs, which the space antenna LISA will capture, can reveal not only a strict rhythm but also its tiny random glitches.

The authors of the study figured out how to extract a measure of disorder from this signal. They introduced a simple mathematical tool — something like a stopwatch that measures not the orbital period itself, but how strongly one orbital oscillation 'remembers' the previous one. Thus, from the noise of the data, a portrait of chaos emerges.

The main result is a simple formula. It shows how the ability to detect these random jolts depends on the total observation time and on how quickly the system 'forgets' its past state. The longer we listen to space, the more clearly we hear the uneven breathing of the stars.

LISA could not just register mergers but become a stethoscope placed on the chest of the Universe. Then arrhythmia would become not an obstacle but a valuable signal. Perhaps it is in these glitches that the physics governing the final chords of the life of double systems is hidden.