In this unit, students investigate the history of timekeeping and experiment with various timekeeping devices. From their experiences, they are introduced to the following concepts, skills, and attitudes.

Concepts

• Time can be measured by observing the natural cycles of the sun and the moon.
• Shadows cast by the sun can be used to measure and predict the passage of time during a day.
• The phases of the moon follow a cycle that can be used to measure and predict the passage of time during a month.
• Mechanical devices can be constructed and used to measure specific intervals of time consistently.
• The accuracy of mechanical clocks is dependent on their design, the materials from which they are constructed, and their energy source.

Skills

• Observing and recording information about the natural cycles of the sun and the moon.
• Learning to plan and conduct experiments in which variables are controlled.
• Predicting and testing how changing a variable affects the outcome of an experiment.
• Interpreting test results to draw conclusions about how changing variables affects the outcome of an experiment.
• Communicating results through writing in notebooks; organizing information in charts, tables, and graphs; and discussion.
• Reading and researching science materials for more information.
• Applying previously learned concepts and skills to solve a problem.

Attitudes

• Developing an interest in exploring and investigating time.
• Recognizing the importance of repeating tests to validate results.
• Appreciating the advances people have made in measuring time and explaining natural phenomena.