As with medicine, Inca science and mathematics did not advance much during the years of the empire because no written language existed. Discoveries resulting from experimentation were often lost because people with scientific interest could not write down the processes or conclusions they derived from their efforts-which also would have enabled them to share these discoveries more widely with others.
Geologic events (earthquakes and volcanic eruptions) and catastrophic weather patterns (droughts or blizzards) were, to the Inca mind, the result of angry gods. The people attempted to mollify the gods’ anger by sacrificing food, cloth, and, occasionally, humans to stop the catastrophe.
Astronomy, a subject that captivated Mayan and Egyptian minds, generated limited Inca interest. People observed the movements of the sun, moon, and the planet Venus. They also recognized the shift in the sun’s path that accompanied the winter and summer solstices. In Cuzco, Inca
Architects built eight towers, four facing the rising sun and four facing the setting sun. The towers were set so that the sun’s path could be traced and noted. On the solstices, the sun left no shadow beside key columns.
Eclipses caused great furor in the Inca Empire. Garcilaso de la Vega described the attitude of the Inca toward solar and lunar eclipses:
For them, when the Sun was in an eclipse, some misdemeanor committed in the kingdom had irritated it, since, at that moment, its countenance had the disturbed look of a man in anger, and they predicted, as astrologists do, the imminence of some severe chastisement. During an eclipse of the Moon. . . they said it was ill, and that if it continued in this state, it would die and fall down to earth; that it would crush them all under the weight of its body, and that this event would be the end of the world. At this thought, they were seized with such fright that they began to play on horns and trumpets, timpani and drums. . . they would tie up their dogs both large and small, and beat them hard to make them bark and bay at the Moon. . . they thought, if the Moon heard them baying for her, she would awaken from the dream in which illness held her a prisoner.
Botany and zoology also held little interest, except as they helped to increase crops or raise healthy llama herds. Through botanical experimentation, the Incas developed new varieties of potatoes and corn that produced more or larger vegetables, greater resistance to frost or cold, or increased production in arid regions.
Mathematics in the Inca world related to practical applications derived by empirical means. Again, the Incas had no written numerical system, so theoretical mathematics never developed. However, mathematical calculations enabled the Incas to survey and portion out acreage among the ayllus. Quipus, the Inca knot database, recorded crop and manufacturing yields, assessed taxes, and recorded payments. In addition to the quipu, the Incas developed a counting board, a yupana, which today’s mathematicians believe was used in the same way as a Chinese abacus.
The Incas relied heavily on their version of the decimal system. Groups of 10 were important to the civil government and within the military. The basic unit of civil management was the ayllu, a group of 10 households. Similarly, the basic unit in the military was a troop of 10 soldiers. From there, Inca management developed larger elements with a leader for each level. A curaca never managed a group of 1,046 households, since unwieldy amounts were unacceptable. Instead, the “extra” 46 households were folded into a new precinct, realigning perhaps dozens of communities to establish precise units.
When the Spanish arrived in the Inca Empire, they were astounded by the accuracy of the Inca census. The civil authorities knew how many people lived in the empire, as well as their age, sex, marital status, profession, social class, productivity, and location. With advanced technology and supercomputers available to the United States government today, a national census is taken every 10 years and the resulting statistics allow for error rates of varying percentiles. The Incas developed enough government bureaucracy to redo their census, reapportion agricultural plots, and reassess taxes every year.
World History
