The seers are well versed on gravity, stars, comets and precession. One very interesting aspect of the seers in science is; they readily have answers to mind boggling or intricate problems but only lack the language to explain their perception.
They have names of major stars and comets because they are entrusted in that duty. The more they go deeper in tracing the movement of the stars the more they become enlightened about the heavenly bodies. In turn, the community relied on them in interpretation of heavenly signs in foretelling about the future.
The community knew some events took place in cycles, some occurring after every decade, others after every fifty years and so forth. In order to keep a steady and accurate source of information in form of records, a college of seers was formed. It was sacerdotal in nature because of its mandate- revealing about heavenly secrets. Every individual seer became a moving encyclopedia of his discipline. In sending out the message , they go down to the lower grade of elders who offer the burnt offerings, then those elders in turn send the message further down until it reaches the ordinary members of the community.
After keen observation of firmament bodies, they realized the accuracy in the movement of the moon, the sun and the stars. In time, they put together the acquired knowledge and became the first concept of a calendar.
The community follows with ease the lunar calendar and the solar or seasons but their third calendar is very complicated to be understood or kept by the ordinary people. It is the seers who inform when to observe the occasion that is held once every 50 years. This calendar takes what Gikuyu call thunguya ithano (five decades). This calendar is based on the movement of Sirius, the Alpha Canis Majoris star’s minor companion Sirius B. Sirius is a binary star system 2.7 pc distance. The brightest star in the night sky, Sirius star or Njata ya Njathi in Gikuyu means the guiding star. Its minor component Sirius B or Kiahu in Gikuyu meaning son or splinter is a dwarf star, with a diameter twice the earth. It has extreme density. Sirius A does not keep a straight path because of high gravitational pull from Sirius B. It makes a serpentine movement. Sirius B is absolutely invisible to the naked eye observation. It became known for the first time in Western astronomy in 1862 when an American astronomer spotted it through a very powerful telescope of the time.
The Gikuyu community celebrated a 50 year jubilee. The most important aspect of the jubilee was the spirit of pardonableness, making it more of a divine forgiveness. The seers knew Njata ya Njathi remained captive of Kiahu’s strong gravitational pull throughout the 50 years course. Similarly, debtors and convicts in the society were known to live under constant stress and harassment, so the fifty year jubilee was set aside as the occasion in which to pardon the accused. The pardonableness in the jubilee required sharing of food together with debtors and convicts and finality was observation of special rituals to cleanse the occasion. The cleansing ceremony was performed by both Maturanguru and Matathi elders. The former attached to divine matters and the latter to judicial affairs. The role of a seer ends at giving the date.