Planet sounds and frequencies: from orbit to rhythm

A planet circles the Sun in a regular time: Mercury in 88, Earth in 365.2, Mars in 687, Jupiter in 4331, Neptune in 59,800 days. Between the fastest and the slowest there is a factor of about 680.

Scaled, these periods become a rhythm. If an Earth year were six seconds, Mercury would turn every 1.4 seconds and Jupiter every 71 seconds. The Planets' Cycles and the Planet Orchestra let you hear this rhythm.

The frequency of a period is one divided by the period. An Earth day (86,400 seconds) corresponds to about 0.0000116 Hz; doubled 24 times it becomes 194.18 Hz. The Earth year 32 octaves up is about 136 Hz.

'Cosmic octave' lists move planetary and Earth periods into the audible range in exactly this way. The calculation is correct; but the idea that moving a period by octaves creates a link with that body has not been tested. Frekans Studio shows these numbers only as the result of the calculation.

A common claim is that 432 Hz is in tune with the planets or the universe. The hertz is a unit tied to the second, which humans defined; a frequency coming out round in this unit shows nothing. The octave multiples of the planets' periods do not gather at 432 Hz either.

TRAPPIST-1 is a small, cool star with seven rocky planets. In the 2021 measurements of Agol and colleagues the periods lie between 1.51 and 18.77 days and neighbours lie near simple ratios: b and c near 8:5, c and d near 5:3. In 2017 Luger and colleagues showed that every one of the seven planets is linked to the others by three-body resonances.

Because the periods differ by only a factor of 12.4, pitch can be data in this system too: each planet's orbital frequency 27 octaves up falls between 83 and 1028 Hz, and the ratios of the seven pitches are the ratios of the periods. Rhythm of Seven Worlds lets you hear it.