Angkor Wat – Equinox

Location:

Cambodia, Latitude 13°25’48” N longitude100°54’00” E

Alignments:

In 1976, University of Michigan researchers suggested that the architect of ancient Cambodia’s Angkor Wat had encoded calendrical, historical and cosmological themes into his architectural plan for the temple. Published in the journal Science, the study demonstrated how Angkor Wat’s architect had established solar alignments between the temple and a nearby mountaintop shrine that took place during the summer solstice. For example, standing at Pre Rup 6 kilometers away at winter solstice, one would see the setting sun over Angkor Wat. Standing near the southwestern corner in Angkor Thom the rising sun at summer equinox will be visible through, or over, the eastern gate. Six months later, the alignment has shifted to its northern point of sunrise at winter solstice.

What is Equinox?The time or date that happened just twice a year at which the sun crosses the celestial equator, when day and night are equal in length (around 22 September and 20 March).

The days are longer around the summer solstice and shorter around the winter solstice. When the Sun’s path crosses the equator, the length of the nights at latitudes +L° and -L° are of equal length. This is known as an equinox. There are two solstices and two equinoxes in a tropical year.

On an equinox, day and night are of approximately equal duration all over the planet. Although they are not exactly equal, it is due to the angular size of the sun and atmospheric refraction.

The Solstices (Summer & Winter)

The summer solstice occurs at the moment the earth’s tilt toward from the sun is at a maximum. Therefore, on the day of the summer solstice, the sun appears at its highest elevation with a noontime position that changes very little for several days before and after the summer solstice.  The summer solstice occurs when the sun is directly over the Tropic of Cancer, which is located at 23.5° latitude North, and runs through Mexico, the Bahamas, Egypt, Saudi Arabia, India, and southern China.  For every place north of the Tropic of Cancer, the sun is at its highest point in the sky and this is the longest day of the year.

The winter solstice marks the shortest day and longest night of the year. In the Northern Hemisphere, it occurs when the sun is directly over the Tropic of Capricorn, which is located at 23.5° south of the equator and runs through Australia, Chile, southern Brazil, and northern South Africa.

The Equinox (Vernal & Autumnal)

There are only two times of the year when the Earth’s axis is tilted neither toward nor away from the sun, resulting in a “nearly” equal amount of daylight and darkness at all latitudes. These events are referred to as Equinoxes. The word equinox is derived from two Latin words – aequus (equal) and nox (night). At the equator, the sun is directly overhead at noon on these two equinoxes.  The “nearly” equal hours of day and night is due to refraction of sunlight or a bending of the light’s rays that causes the sun to appear above the horizon when the actual position of the sun is below the horizon.  Additionally, the days become a little longer at the higher latitudes (those at a distance from the equator) because it takes the sun longer to rise and set.  Therefore, on the equinox and for several days before and after the equinox, the length of day will range from about 12 hours and six and one-half minutes at the equator, to 12 hours and 8 minutes at 30 degrees latitude, to 12 hours and 16 minutes at 60 degrees latitude.

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The builders of Angkor Wat creating a temple not only to honor their deities but in its very structure and orientation of the greater cosmic

The origins of the temple – Angkor Wat

It is to Vishnu that Angkor Wat is consecrated, and with more than mere symbolic intent. Hindu temples were built to be earthly abodes for the gods. The central sanctuary was the most sacred place, directly inline with the vertical axis of the central spire that provided the connection between the realms of heaven and Earth. The surrounding architecture of the temple would then mirror Hindu cosmology, being essentially a mandala in stone—a diagram of the cosmos itself. Furthermore, the Khmer civilization had by the time of Angkor Wat’s construction incorporated the idea that a king would, after his death, be transmuted into one of the gods. Hence, it was at Angkor Wat that Suryavarman II, after his death, was believed to reside as Vishnu.

As far as the interpretation of each temple is concerned, the complexity of the  relationship between the two Khmer religions – Buddhism and Hinduism – must be taken into account. This relation was sometimes exclusive and other times, in dependence of the attitudes of the ruling king. Documented historical phases of Buddhism/Hinduism explicit conflict and consequent defacing of temples’ images also exist. In any case, construction of the temples was clearly considered as mandatory to attest to the greatness and in some sense to the divinity of the king himself. The temples thus reflected concepts related to the foundation of power and to the cosmic order; as a consequence, it comes as no surprise that a complex religious symbolism is self-evident in all these buildings. Inspiration certainly was in Indian sacred architecture values.

Astronomical significance:

Astronomy and Hindu cosmology are inseparably at Angkor Wat. While it is more evident than in the interior colonnade itself, which is dedicated to a vast and glorious carved, 12,900 sqft. of bas-relief, illustrating the gods as well as scenes from the Hindu epic Mahabharata.  In Cardinal directions the outer walls measuring approximately 2,600 ft

• The East Wall is the scene illustrating “The Churning of the sea of Milk,” a creation myth in which the gods attempt to churn the elixir of immortality out of the milk of time.
• The North Wall to The West Wall depicts the “day of the gods,” is a great battle scene from Hindu Epic Mahabharata, continuing to further west is the depiction of King Suryavarman II, in full royale possessions.
• The south wall portrays the Kingdom of Yama, the god of death.

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It has been suggested that the choice and arrangement of these scenes was intended to tie in with the seasons—the creation scene of the east wall is symbolic of the renewal of spring, the “day of the gods” is summer, the great battle on the west wall may represent the decline of autumn, and the portrayal of Yama might signify the dormancy, the lifeless time of winter.

Here’s the FactsThe architecture of Angkor Wat also has numerous astronomical aspects beyond the basic mandala plan that is common to other Hindu temples. As many as 18 astronomical alignments have been identified within its walls.

Some of the alignments are prominent are: 

• on spring equinox, the sun rises over the central tower;
• on the winter solstice, it rises over a temple at Prasat Kuk Bangro, 5.5 km away;
• on the summer solstice it rises, over a prominent hill Phnom Bok, 17.5 km away.

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The Measurements in Khmer Empire
Some researchers have claimed that the very dimensions of many of the structures at Angkor Wat have astronomical associations. These associations emerge from consideration of the unit of length that was in use at that time, a unit known as the hat or “Cambodian cubit unit.” There is some question as to how long a hat was, and indeed its definition may have not been applied rather a value equal to 43.45cm or 17 inches for the length of a hat is suggested by the structures themselves.

 Using this value, archaeologists discovered numerous dimensions of the temple that deem to have astronomical and cosmological significance — for example,

• The dimensions of the highest rectangular level of the temple are 189 hat in the east-west direction and 176 hat in the north-south direction. Added together these give 365, the number of days in a year.

• In the central sanctuary, the distances between sets of steps is approximately 12 hat. There are 12 lunar cycles (from full moon to full moon, refer the basis for our modern month in a year.

• The length and width of the central tower add up to approximately 91 hat. On average, there are 91 days between any solstice and the next equinox, or any equinox and the next solstice, that is the 4 season in a year.

Because of its orbit around the Earth, the Moon’s apparent position in the sky relative to the background stars will appear to shift from night to night. Since it takes the Moon just over 27 days to complete one orbit (known as its sidereal period), it will during this time appear to move through 27 successive regions of the sky. In Hindu cosmology, these regions were known as the naksatras, or lunar mansions. In some contexts there were 27 lunar mansions, while in other contexts an additional naksatra containing the star Vega was included, giving 28 lunar mansions.

Hindu cosmology recognizes four time periods, or Yugas, that are represented in the dimensions of the temple:

The central tower at Angkor Wat contains nine inner chambers. If you total the dimensions of all of these chambers it equals 27 hat in the north-south direction and 28 hat in the east-west direction, corresponding to the possible number of lunar mansions. Also, the libraries have lengths measured along their interiors of 16 hat in the east-west direction, and either 12 or 11 hat in the north-south direction, depending upon whether or not the doorways are included. Added together, these also give either 28 or 27 hat. Finally, the north-south width of the libraries measured from the exteriors of the wallsis again 28 hat. The Bhagavata Purana, discusses a wide range of topics including cosmology, genealogy, geography, mythology, legend, music, dance, yoga and culture.

• The length of the Kali Yuga, is 2 x 603 years, or 432 thousand years.
  • The width of the moat surrounds the temple, is approximately 432 hat. 
• The length of the Dvapara-Yuga is 4 x 603 years, or 864 thousand years.
  • The distance from the entrance to the inner wall is 867 hat.
• The length of the Treta-Yuga is 6 x 603 years, or 1,296 thousand years.
  • The distance from the entrance to the central tower is 1,296 hat.
• The length of the Satya-Yuga is 8 x 603 years, or 1,728 thousand years.
  • The distance from the moat bridge to the center of the temple is 1,734 hat.

Rarely in history has any culture given rise to a structure that so elaborately and expansively incorporates its concept of the cosmos. Angkor Wat stands as a striking and majestic monument in honor of the Universe and our place in it.

SRG Holidays Cambodia arrange special visit during the Equinox each year for photographer comfort and do check with us on the special rate.