Platonic Year (Cosmic Octave)
172.06 Hz
Nearest note: F3, 26 cents below standard tuning
The slow wobble of the Earth’s axis, counted by its traditional length of 25,920 years and doubled 47 times.
How well is this supported?
Calculated from a measured value by a stated method. You can check the arithmetic. What the result means is a matter of interpretation.
Cousto uses the traditional figure of 25,920 years. The measured rate of precession gives about 25,772 years. The tone is calculated by doubling, so that it can be heard. Nothing in space makes this sound.
The button plays a plain tone. Start with the volume low. Phone and laptop speakers play low notes quietly; headphones or a speaker help.
Where this number comes from
The axis of the Earth slowly traces a circle, which shifts the equinoxes against the stars. Cousto uses the traditional length of that cycle, 25,920 years (360 × 72). 1 ÷ 817,955,521,264 seconds, doubled 47 times, is 172.06 Hz. That is an F, about 26 cents below standard tuning. The measured rate of precession gives a cycle of about 25,772 years, which would put the tone about 10 cents higher.
- Step 1. Start with the length of the cycle
Precession of the equinoxes: 25,920 years (traditional figure).
- Step 2. Turn it into a frequency
One divided by that many seconds is 1.22 × 10⁻¹² Hz. That is far too slow to hear.
- Step 3. Double it 47 times
Doubling a frequency raises it by one octave: the same note, higher. After 47 doublings it is 172.06 Hz.
- Step 4. Name the note
172.06 Hz is an F, 26 cents below standard tuning. A cent is one hundredth of the step between two neighboring piano keys. To play in tune with this tone, an instrument sets its A to 433.56 Hz instead of 440.
- Step 5. Keep doubling and the number lands in the range of light
42 more doublings give the frequency of light with a wavelength of 396 nm, which is red-violet. This is arithmetic. It pairs a tone with a color; it does not show that the two are connected.
The method is Hans Cousto’s. Planet gongs explained walks through it and says what it does and does not show.
What is said about it
What is said, not what was measured
Cousto assigns this tone to the crown chakra. In astrology the cycle is divided into twelve ages, such as the Age of Aquarius.
Facts
- Frequency
- 172.06 Hz
- One cycle takes
- 25,920 years
- Wavelength in air (20 °C)
- 1.99 m
- Nearest note
- F3, 26 cents below standard tuning
- Kind of statement
- Octave of an astronomical cycle
- Filed under
- Earth, Moon & Sun
Tuning Data
The row for this tone in Hans Cousto’s tables, with the tempo and pendulum length that follow from it.
- Cycle
- Precession of the equinoxes
- Length of the cycle
- 25,920 years (traditional figure)
- Octaves up
- 47
- Concert pitch (A)
- 433.56 Hz
- Difference from A = 440 Hz
- -25.51 cents
- Tempo
- 80.65 beats per minute
- Pendulum length
- 13.8 cm / 5.41 in
- Color by octave
- Red-Violet (396 nm / 792 nm)
Tempo and pendulum length, octave by octave
| Octave | Frequency | One cycle | Tempo | Pendulum |
|---|---|---|---|---|
| 40tempo | 1.34 Hz | 743.93 ms | 80.65 BPM | 13.8 cm |
| 41 | 2.69 Hz | 371.96 ms | 161.31 BPM | 3.4 cm |
| 42 | 5.38 Hz | 185.98 ms | Too fast to count | Too short to build |
| 43 | 10.75 Hz | 92.99 ms | Too fast to count | Too short to build |
| 44 | 21.51 Hz | 46.50 ms | Too fast to count | Too short to build |
| 45 | 43.02 Hz | 23.25 ms | Too fast to count | Too short to build |
| 46 | 86.03 Hz | 11.62 ms | Too fast to count | Too short to build |
| 47tone | 172.06 Hz | 5.81 ms | Too fast to count | Too short to build |
Intervals built on this tone
| Ratio | Interval | Frequency | Note | Concert A | Cents from 440 |
|---|---|---|---|---|---|
| 1/1 | Perfect unison | 172.06 Hz | F3 | 433.56 Hz | -25.51 |
| 81/80 | Syntonic comma | 174.21 Hz | F3 | 438.98 Hz | -4 |
| 531441/524288 | Pythagorean comma | 174.41 Hz | F3 | 439.48 Hz | -2.05 |
| 128/125 | Diesis | 176.19 Hz | F3 | 443.97 Hz | +15.55 |
| 648/625 | Greater diesis | 178.39 Hz | F3 | 449.52 Hz | +37.06 |
| 25/24 | Chroma | 179.23 Hz | F3 | 451.63 Hz | +45.16 |
| 16/15 | Diatonic semitone | 183.53 Hz | F#3 | 436.51 Hz | -13.78 |
| 10/9 | Minor whole tone | 191.18 Hz | G3 | 429.18 Hz | -43.11 |
| 9/8 | Major whole tone | 193.57 Hz | G3 | 434.54 Hz | -21.60 |
| 8/7 | Septimal whole tone | 196.64 Hz | G3 | 441.44 Hz | +5.66 |
| 6/5 | Minor third | 206.47 Hz | G#3 | 437.50 Hz | -9.87 |
| 5/4 | Major third | 215.08 Hz | A3 | 430.15 Hz | -39.20 |
| 4/3 | Perfect fourth | 229.41 Hz | A#3 | 433.07 Hz | -27.47 |
| 3/2 | Perfect fifth | 258.09 Hz | C4 | 434.05 Hz | -23.56 |
| 8/5 | Minor sixth | 275.30 Hz | C#4 | 437.01 Hz | -11.82 |
| 5/3 | Major sixth | 286.77 Hz | D4 | 429.66 Hz | -41.15 |
| 7/4 | Natural seventh | 301.11 Hz | D4 | 451.15 Hz | +43.32 |
| 16/9 | Pythagorean minor seventh | 305.88 Hz | D#4 | 432.59 Hz | -29.42 |
| 9/5 | Just minor seventh | 309.71 Hz | D#4 | 437.99 Hz | -7.91 |
| 15/8 | Major seventh | 322.61 Hz | E4 | 430.64 Hz | -37.24 |
| 2/1 | Octave | 344.12 Hz | F4 | 433.56 Hz | -25.51 |
Source notes
Cousto uses 25,920 years, the traditional figure (360 × 72). The measured rate of precession gives about 25,772 years, which would put the tone about 10 cents higher.
Source: Hans Cousto — Tuning Data / Sun Earth Moon Planets. View the source PDF, page 9.
License: CC BY-NC-ND 4.0, as stated in Stimmdaten.pdf (German edition), page 2.
Values are reproduced from Cousto’s tables. Tempo, pendulum length and interval tables are calculated by this site from those values.
See every tone in the tables: Open the tuning data reference.
Sources
- Hans Cousto — Tuning Data: Earth, Moon, Planets, Sun
The tables that the tuning pages on this site reproduce.
Hans Cousto, Tuning Data — Earth Moon Planets Sun. Planetware.
View source: Hans Cousto — Tuning Data: Earth, Moon, Planets, Sun - Hans Cousto — Tuning Data / Sun Earth Moon Planets — Earth — Platonic Year
Cousto uses 25,920 years, the traditional figure (360 × 72). The measured rate of precession gives about 25,772 years, which would put the tone about 10 cents higher.
View source: Hans Cousto — Tuning Data / Sun Earth Moon Planets — Earth — Platonic Year
More about the pitch
The same note in every octave
Each step doubles or halves the frequency. Tap one to hear it.
Whole-number multiples
Two, three, four times the frequency, and so on. A string or a flute sounds overtones at these values. A gong does not follow this pattern.
Entries close in pitch
Within 35 cents of this tone, in any octave. A cent is one hundredth of the step between two neighboring piano keys. Being close in pitch does not mean two things are connected.