Chaco Canyon
In Chaco Canyon, NM the ancestors of the Pueblo used several methods to measure time and seasons including alignment of moon and sun through windows, or through cracks in order to cast a light mark on a stone wall.

Humans have been measuring time since before written history. Clocks and time measurement in general is a key component of all complex instruments. In this section we will cover some of the most important types of clocks.

Early civilizations used various methods to measure both hours and seasons. In most cases the sun and the light it cast was used. Today scientists and engineers can measure down to the attosecond, or one quadrillianth of a second! Without a highly accurate clock we would not be able to work with certain lasers, GPS and other technologies.

In this part of the course we talk about mechanical means of time keeping, the quartz clock and the atomic clock.