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The Great Year and Platonic Cycles
The study of Platonic solids reveals that the same sacred numbers also govern the cycles of time. Plato wrote of a grand cosmic cycle known as the Great Year, which he suggested lasted 36,000 years—possibly an allusion to the Saros Cycle (3,600 years) used by the Babylonians. However, the actual duration of the Great Year is calculated as 25,920 years by Hipparchus, two centuries after Plato. Since Plato first referenced these time cycles and they were further developed by his philosophical school, I will refer to these time units as Platonic.
Sacred Numbers in Platonic Solids
The angles and proportions of the Platonic Solids reveal sacred numbers that are significant in both ancient astronomy and astrology. For example:
Volume Face Shape Angle of Face Sum of Face Angles Sum of Volume Angles
Tetrahedron Triangle 60 x 3 180 x 4 720
Octahedron Triangle 60 x 3 180 x 8 1440
Cube Square 90 x 4 360 x 6 2160
Icosahedron Triangle 60 x 3 180 x 20 3600
Dodecahedron Pentagon 108 x 5 540 x 12 6480
These numbers are reflected in various cosmic cycles. The sum of the cube’s angles, 2160º, corresponds to the number of years it takes for a zodiac sign to align with the spring equinox during the Precession of the Equinoxes. Each of the 360 degrees of the ecliptic is divided into segments that echo these sacred numbers. The number 360 itself is foundational in many ancient systems, representing wholeness and the cyclical nature of time. In both geometry and astrology, 360 degrees symbolizes the complete circle of creation, with its subdivisions echoing key sacred numbers.
Platonic Time Cycles and the Zodiac
Many of these numbers will be recognizable to enthusiasts of ancient astronomy and astrology. For instance, the face of a cube is a square made of four 90-degree angles (totaling 360), and six of these faces make it a three-dimensional shape. Adding up all the angles of the cube makes 2160. These numbers match the 360 degrees of the ecliptic and the number of days in early solar calendars like the Egyptian. 2160 is the number of years that a zodiac sign will rise with the spring equinox before another sign enters it in the Precession of the Equinox, or Great Year, where the stars shift one degree every 72 years. 72 is evenly divided in the 360º ecliptic into 5º increments. In the tropical or solar zodiac, Aries will always mark the beginning of spring regardless of the stars that rise with it, the yearly seasons being an eternal cycle of light and dark in and of themselves.
Sacred Geometry in Timekeeping
Just as sacred numbers govern the structure of the universe, they also play a key role in how humans measured and understood time. Timekeeping in the ancient world, especially before the Ptolemaic era, was also governed by sacred numbers and geometry. The Egyptian system was based on the 36 Decans, or 36 increments of 10 days each, totaling 360, and the ecliptic was divided into 10º divisions of stars. An extra five sacred days were added to synchronize it with the 365 days of the solar year and they divided the day and night into 12 hours each. On the equinox, the hours of light and darkness are a perfect 12 hours each, or 720 minutes.
- 1 Tropical/Solar Day: 24 hours
- 24 hours × 60 minutes = 1,440 minutes
- 1,440 minutes × 60 seconds = 86,400 seconds (total in 24 hours)
- 720 minutes × 60 seconds = 43,200 seconds (12 hours)
These numbers relate to the Platonic solids, where their angular sums correspond to time units. For example, the cube represents Earth and has a sum of 2,160º, the same number of years in a Platonic month.
Platonic Time Units and the Precession of the Equinoxes
When the total angles of each Platonic Solid are added together, each becomes a significant measurement of time. For example, the tetrahedron has an angle of 180º and four faces. 4 X 180 is 720, the number of minutes in one hour. The cube, which is the Form of Earth, has angles of 90 degrees, four on each face, 4 x 90 is 360. The sum angles of the cube’s six faces (6 x 360) are 2,160, one month or Platonic Month of the Great Year lasting 25,920 years.
During the Precession of the Equinoxes, the stars shift by 1 degree every 72 years(one Platonic Day), completing a full cycle in 25,920 years. This precession synchronizes the sidereal zodiac with the tropical zodiac, where the constellation of Aries eventually returns to align with the tropical sign of Aries.
Sacred Numbers Governing the Platonic Year
The sacred numbers in the Platonic Year reflect the same geometric principles found in the Platonic Solids. Below is a breakdown of key time cycles and their corresponding solids:
- 1 Decan (10º) = 720 years | 10 days, 240 hours, 1,440 minutes | Tetrahedron 720º
- 2 Decans (20º) = 1,440 years | 20 days, 480 hours, 28,800 minutes | Octahedron 1,440º
- 3 Decans (30º), 1 Sign = 2,160 years | 30 days, 720 hours, 43,200 minutes | Hexahedron 2,160º
(1 Zodiac Sign, 1 Platonic Month) - Saros Cycle (60 x 60) = 3,600 years | 50 days, 1,200 hours, 72,000 minutes | Icosahedron 3,600º
- 3 Platonic Months, 1 Season = 6,480 years | 90 days, 2,160 hours, 129,600 minutes | Dodecahedron 6,480º
- 1 GREAT YEAR = 25,920 years | 360 days, 6,480 hours, 518,400 minutes | Platonic Year
Sacred Numbers and the Structure of Time
In the grand cosmic scale, one Platonic Day equals 72 years, during which the fixed stars move 1 degree in the zodiac, similar to how the Sun moves 1 degree in a 24-hour solar day. A Platonic Month lasts 2,160 years, a Platonic Season spans 6,480 years, and the Great Year encompasses 25,920 years.
The numbers 72, 144, and 360 have deep mystical significance in ancient civilizations. The number 72 is sacred in many cultures, partly because it is the product of multiplying 12 (the number of zodiac signs) by 6 (a number associated with balance and harmony). Similarly, 144 (12 x 12) represents completion and spiritual fulfillment, often appearing in sacred texts as a symbol of divine order. The number 360, the degrees in a circle, represents wholeness and the cyclical nature of time, as ancient astronomers used it to track celestial movements and seasonal changes.
These numbers bridge the realms of astronomy, astrology, and numerology, showing how mathematical principles connect the physical and metaphysical worlds.
Within these vast cycles, the tropical zodiac completes smaller cycles of light and dark, like wheels within wheels. All of this is governed by sacred geometry, the same principles observable in the Platonic Solids. Interestingly, the average human lifespan of approximately 72 years parallels the length of one Platonic Day, drawing an analogy between the tropical zodiac as a map of human lives and the sidereal zodiac as a map of creation’s life.
The Twelfths of the Zodiac Signs (Dwads)
Divisions of these numbers reveal the underlying schemes used in ancient astrology. For instance, the Twelfths of the Signs (Al-Biruni, 456), where each 30º sign is divided into 12 increments of 2º30’ or 2 ½ degrees. This division is based on the sacred number 144.
These subdivisions, known as Dwads (or Duad Decans), further refine the zodiac by dividing each sign into twelve equal parts. Each Dwad is 2º30′ long and is associated with the characteristics of another zodiac sign. For example, the first 2º30′ of Aries is Aries-Aries, the second Dwad is Aries-Taurus, and so on. This creates a “sign within a sign” effect, adding nuance to natal chart interpretations.
In practical astrology, Dwads are used to deepen chart readings by revealing underlying traits that might not be immediately obvious in a broader interpretation of the sun sign or ascendant. This granular approach reflects the fractal nature of time and the cosmos, where larger cycles mirror smaller ones, allowing astrologers to explore the multi-layered influences in a person’s life or events.
There are 1,440 minutes in one day. It takes 1,440 years for the star clusters in two 10º Decans shift positions in the ecliptic. Dividing 1,440 by 10 gives 144, which is perfectly divisible by 12, reflecting the structure of the zodiac. Each zodiac sign is divided into 12 increments of 2 ½ degrees, creating a “fractal” effect—where signs exist within signs—illustrating the mystical geometry of time and enhancing the depth of astrological interpretations. This is but one example of obscure Hellenistic and medieval Arabic astrological schemes that were made using the principles of sacred numbers.
Twelfths of the Signs (Dwads)
The Mystical Significance of Sacred Numbers
Across all measurements of time—whether thousands of years, days, or minutes—certain sacred numbers consistently reappear. The 360º ecliptic has been in use since at least 5,000 years ago by the Sumerians. Ancient civilizations used the sexagesimal system (counting based on 60) and base 10 (all numbers depending on powers of 10), both of which are still in use today.
The number 60 is especially significant because it can be evenly divided by many numbers: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30, making it highly practical for measuring time and astronomical events. The 360º circle is easily divided by 60, and each degree of the ecliptic is further divided into 60 minutes and each minute into 60 seconds, forming the foundation of modern clocks. In astrology, the ancient system of Terms or Bounds, numbering five per zodiac sign (60 in total), reflects this sexagesimal structure, emphasizing its mystical and practical significance.
This scheme was already ancient when Claudius Ptolemy wrote Tetrabiblos almost 2,000 years ago, so much that he had no explanation of their rationale or for their variations. 60 and 10 are the numbers that most often reveal the significance of large units of time when divided.
For ancient astrologers, these sacred numbers were not only used for theoretical purposes but also had practical applications in everyday life. Astronomers/astrologers employed these numerical frameworks to predict celestial events such as eclipses, seasonal shifts, and even personal astrology charts. By calculating planetary positions and their relationships using these sacred numbers, astrologers were able to offer detailed interpretations of both cosmic events and individual destinies. In this way, sacred geometry and mathematical principles became essential tools for understanding the universe and forecasting its rhythms.
These sacred numbers continue to influence modern astrological calculations, from the interpretation of natal charts to transit predictions and horary astrology. This mystical system of sacred numbers serves as a bridge, linking the ancient wisdom of astronomy with the practice of astrology, reminding us that the universe operates on both spiritual and mathematical principles.
Astrological Schemes and Mystical Mathematics
The numbers 12, 30, 36, 72, 144, and the sacred numbers of the Tetractys are found throughout astrological schemes in varying orders of magnitude. Until the past three centuries, astronomers were also astrologers. The mathematical foundations of astrology were not only used for impressively complex astronomical calculations, but these same numbers had immense mystical significance as well.
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