When people think of Science they often think of knowledge like the periodic table, or the equations. However, Science is actually a process of obtaining knowledge by observing, experimenting, and reflecting. We often call this the scientific method. Unfortunately this observing and experimenting has been going on for hundreds of years and so we often streamline our teaching of Science by cutting it right down to the knowledge we gained rather than the process of gaining knowledge. 

Science deals with models. A model is a set of rules and ideas that match current observations and can be used to predict future observations. e.g. a model could say that the sun moves around the earth. This is why the sun moves through the sky. I can predict that eventually the sun will move completely around the earth and rise again tomorrow morning. This would be perfectly valid if the movement of the sun through the sky was the only observation.

The models we have in Science are accepted until they no longer match current observations. e.g. certain stars (the planets) were seen to move strangely (what was called retrograde motion) and this could not be explained if they were moving around the earth. The model was then changed so that everything was moving around the sun. This explained all the observations we had and could be used to predict future observations such as why we only see certain stars at certain times of the year. The pictures to the right show the cause of this motion and also a picture of the motion of mars through consective nights. 

Nearly every group of people around the world developed a method of time keeping. Some used the stars and constellations, others used the moon or the sun. In fact, that is why we have 12 months in a year as the moon goes through roughly 12 full cycles in a year. The Chinese calendar is a combination of all three. 

The Māori used lunar and star cycles (such as the rising of the Matariki constellation) to help them navigate, mark the seasons, predict the migration of birds and fish, and also know when to plant and harvest crops. 

The Gregorian calendar (the calendar most countries use now) is based on the position of the Earth as it orbits around the sun. The Earth completes 365.25 rotations (days) during one orbit of the sun. This is why every 4 years we have a leap year (366 days in it) rather than a traditional year (365 days), to compensate for that extra 0.25 rotations completed per year.

Every method of time keeping was developed through the use of science and a scientific method. People had to observe the cycles of the stars, sun, and planets. They then had to develop a model and use that model to make predictions. This is what Science is all about.