108 was a sacred number already at the
time of the Buddha, probably due to the astrological system
that came from Sumeria around 5,000 years ago and was
adopted by the Indus Valley civilisations. It gave Europe and
Asia the 7day week and the 12month year, which are found
everywhere to this day. 108 has been a number sacred for
Hindus, Buddhists and Jains for at least 2,500 years. It is
also found in the West, through
the Greeks who also got their
astrology and numbers from Sumerian origins. The main
astrological reasons were put together in the Kalachakra
Tantra, which came to Tibet in 1027   quite late on.
Why 108? here are some of the answers:
1. Astrologically, it is the combination of the 9 heavenly
bodies (mainly planets  Sun, Moon, Mercury, Venus, Mars,
Jupiter, Saturn, the North Node and the South Node.) with the
12 houses of the Zodiac. 12 times 9 = 108. On a more secret
level, the number 9 is associated with Saturn (Za Penpa) and
you may have seen the 12 sets of Saturn "magical squares" set
around a Tibetan astrological chart. This is used to calculate
Mewas and Parkas.
There are 108 squares in the diagram below.
There are also, in astrology, the 27 Lunar
Mansions (Tib: "Jukar", Skt: nakshatras) and if one combines
these with the 4 phases of the Moon, that gives 108. This
comes through in the sacred yoga teachings of
corresponding inner prana movemments too (see next entry).
In the Kalachakra tantra, these outer 108
are corresponded to the inner 108 major, secondary and
tertiary channels deriving from the heart centre.
2. In Buddhism, it becomes the main number
of possible experiences. It works like this  there are the
six consciousnesses (seeing, hearing, smelling , tasting,
physical sensation and mental). These can be either pleasant,
unpleasant or neutral so that makes 18 possibilities. There
are the three times (past, present and future) in which these
can occur, so that makes 3 x 18 = 54. Then they can be either
virtuous or nonvirtuous = 108.
3. Numerology. The number has fascinated
mathematicians all over the world because it is
(1) multiplied by (2 x 2) multiplied by (3
x 3 x 3) ....one one, two twos and three threes.
4. The Greeks' famous beautiful
architecture was based on a heightwidth relationship know as
the "Golden Rule". You get this by taking two points 108 apart
on a circle, joining them with a straight line and comparing
that to the circumference of the circle.
5. The ancients didn't know all of the
following, but by an incredible "coincidence" ,
the distance between the Earth and the Sun is 108 times the
Sun's diameter,
the distance between the Earth and the Moon is 108 times the
Moon's diameter and also
the diameter of the Sun is 108 times that of the Earth.
(Just by coincidence, but not so relevant,
the radius of the Moon is 1086 miles.)
6.This is more debatable. The Hindu
pantheon of Gods is 108: some people say that these were
'upgraded' by tantra to make 108 main deities in Buddhism.
This is certainly why the Hindus think it is a holy number. Of
course, the deities are representations of cosmic realites, so
we come back to the inner channels and the outer cosmos.
Mathematical &Scientific Data for above
Distance between earth and sun = 108 times
sundiameter
The diameter of the Sun has not been easy for scientists to
measure. These are the numbers:
1,392,000 km ("Sun" Columbia Electronic Encyclopedia. 6th ed.
Columbia University Press, 2003)
 1,400,000 km (Namowitz, Samuel N. and Spaulding, Nancy E. Earth
Science. Evanston, IL: McDougal Littell Company, 1999)
 1,390,000 km (The Amazing Structure of the Sun. National
Aeronautics and Space Administration (NASA), 2003)
 1,380,000 km (Namowitz, Samuel N., and Nancy E. Spaulding. Heath
Earth Science. Lexington, MA: Heath, 1994: 398.)
The distance between the earth and the Sun is called an
Astrological Unit (AU).
1 AU = 149,597,870.691 kilometers
Even though this is the number given there are multiple places
where variability gets into the numbers. One way is the elliptical
orbit of the earth around the Sun.
Perihelion: 147.5 million km, about January 4th
Aphelion 152.6 million km, about July 4th
(http://science.nasa.gov/headlines/y2001/ast04jan_1.htm)
Findings:
Taking the mean distance between the earth and the Sun (
149,597,870.691 km) and dividing it by the most commonly used
diameter of the Sun (1,392,000 km) the result is
107.46973469181034482758620689655.
2. Distance between earth and moon = 108 times
moondiameter
Moons diameter is: 3,474.8 km
(http://en.wikipedia.org/wiki/Earth)
Distance from earth to the Moon:
Again the Moons rotation is elliptical and not an exact circle.
But Apollo 11 astronauts put mirrors on the Moon and lasers
measure the amount of time it takes for the light to reflect, this
gives measurements with accuracy up to a few inches at any given
time.
Perigree 363,300 km
Apogee 405,500 km
Mean Distance 384,400 km
(http://www.freemars.org/jeff/planets/Luna/Luna.htm)
Findings:
Taking the mean distance from the Moon to the Earth (384,400 km)
and dividing it by the Moons diameter (3,474.8 km) results in
110.62507194658685391965005180154.
3. Diameter of the sun = 108 times the earth
diameter
The diameter of the earth is: Equatorial diameter 12,756.28 km
Polar diameter 12,713.56 km
Mean diameter 12,742.02 km
_____________________________
The angle of 108 has a unique property: the ratio between the
straight line uniting two points at 108 from each other on a
circles circumference (in effect one of the sides of a 10pointed
star) and the radius of that circle equals the Golden Section.
Likewise, the inside of every angle of a pentagon measures 108,
and the pentagon is a veritable embodiment of the Golden Section,
e.g. the ratio between a side of the 5pointed star and a side of
the pentagon is the Golden Section. So, there is an
intimate link between the number 108 and the Golden Section.
