Pluto tuning fork — 140.25 Hz

140.25 Hz is the planetary tone of Pluto, and it is the only row in the set where tuning forks honestly exist at two different numbers: 140.25 and 140.64 Hz.

Pluto in true color, imaged by New Horizons. The dispute over the second frequency, 140.64 Hz, is about exactly this planet's orbital period · NASA/JPL, public domain

Frequency (middle octave)	140.25 Hz
Note	C# · +21 cents from standard tuning A = 440 Hz
Tuning in which this is an exact note	A = 445.26 Hz
Cycle	orbit around the Sun248.4 years (the value Cousto used)
Doublings from the cycle's frequency	40
Color (the same frequency as light)	blue-green · 486 nm
Paint on the Acutonics tuning fork	blackshade measured from photos in the school's catalog — this is NOT the computed colorcolor name “Black” — school page · Acutonics Canada
What can be checked	Reproducible

The reason is not mystical but a matter of bookkeeping: Pluto's orbit was refined over time. The old value of the period gave 140.25 Hz, and Cousto's classic set is built on it; the revised booklet already prints 140.64. Forks are sold at both numbers, so both remain “official”. Which of the two the Acutonics school's Pluto fork uses is unknown: the school does not publish hertz, its note, C sharp, fits both, and the two numbers are less than five cents apart, a difference a recording of a fork cannot resolve.

A curious consequence: sound two such forks together and they beat roughly once every two and a half seconds. The difference between two “official” truths turns out to be audible.

In tradition, Pluto stands for transformation and for working with what has outlived itself. Paired with Om it gives 4.15 Hz: the theta range and, as the method describes it, the most “alive” pulsation of all.

How this number is obtained

The axis is logarithmic: each doubling raises the sound by exactly one octave. The pitch goes up, the note stays the same.

Given: the period of Pluto

248.4 years (the value Cousto used) = 7 839 694 080 seconds

1The frequency of the cycle itself: how many times it repeats per second

1 ÷ 7 839 694 080 = 0.000 000 000 127 56the same in short form: 1.28 × 10⁻¹⁰ Hz

A tiny number that cannot be heard: human hearing starts at about 20 Hz. But it is a real frequency, and we can keep working with it.

2Raising it into the audible range: each doubling is one octave up

0.000 000 000 127 56 × 2 = 0.000 000 000 255 111st doubling

0.000 000 000 255 11 × 2 = 0.000 000 000 510 222nd doubling

0.000 000 000 510 22 × 2 = 0.000 000 001 020 43rd doubling

⋮36 more doublings just like these

70.12 × 2 = 140.2540th doubling: now it is in the middle fork band

Or, in a single line:

0.000 000 000 127 56 × 2⁴⁰ = 140.25 Hz

where 2⁴⁰ = 1 099 511 627 776, the number of times the frequency has grown

The value Cousto published is 140.25 Hz. It matches.

3Which note it is

12 × log₂(140.25 ÷ 440) = −19.79semitones from A

nearest whole number: −20 = C#and that is the note

remainder: 0.21 of a semitone = 21 centshow far the tone is from the note

One hundred cents make one semitone. Planetary frequencies almost never land exactly on a note: orbits know nothing about musical tuning.

4In which tuning it would be an exact note

140.25 ÷ 2^(−20 ÷ 12) = 445.26 Hz

An ordinary piano is tuned to A = 440 Hz. Here the tone gets a tuning of its own, and for the Om tone it is exactly the much-discussed 432 Hz.

5Color: the same frequency raised all the way to light

140.25 × 2⁴² = 616 822 956 242 001 Hzthat is 6.17 × 10¹⁴ Hz, already visible light

299 792 458 ÷ 616 822 956 242 001 = 486 nmwavelength → blue-green

Divide the speed of light by the frequency and you get the wavelength. This is a model, not the measured color of a planet, but the arithmetic is exactly the same as for sound.

Octave ladder

Octave	Frequency	How it is used
2^37	17.53 Hz	below or at the edge of hearing
2^38	35.06 Hz	below or at the edge of hearing
2^39	70.12 Hz	low: stronger vibration on the body
2^40	140.25 Hz	the main tuning fork
2^41	280.50 Hz	high: work in the field above the body
2^42	561.00 Hz	high: work in the field above the body

Two values, and both are “official”

frequency: 140.25 Hz (classic Cousto: the 1984 book and the list of forks in his booklet) and 140.64 Hz (Cousto's revised booklet: the tables and the Pluto page).

Pluto's orbit was refined: the old period value gave 140.25 Hz, the new one 140.64. Forks are sold at both numbers, so both remain “official”. Which of the two the Acutonics school's Pluto fork uses is unknown: the school does not publish hertz, its note, C sharp, fits both, and the two numbers are less than five cents apart, too little for even a measurement from a recording to tell apart.

What tradition ascribes

Tradition

Transformation, letting go, shadow work.

This is a system of correspondences, not the result of a measurement: controlled studies of planetary frequencies do not exist. We present the tradition because it exists and the practice is built on it — but we call it tradition.

All frequencies in one chart · how the calculation works · what has been proven