Cover -- Title Page -- Copyright -- Contents -- Introduction -- The Perception of Time -- Experiment 1: Time Test -- The Day: A Natural Unit of Time -- Experiment 2: The Sun's Midday Altitude -- Experiment 3: Modeling the Sidereal Day Versus the Solar Day -- Experiment 4: Earth's Speed Along Its Orbit -- Experiment 5: Making an Analemma -- The Lunar Month: A Natural Unit of Time -- Experiment 6: Measuring the Lunar Month -- The Year: A Natural Unit of Time -- Experiment 7: Finding Sirius and Constellations in the Winter Sky -- The Hour: A Logical Unit of Time -- Experiment 8: A Shadow Clock -- Experiment 9: Making a Sundial -- Time Around the Earth -- Experiment 10: Crossing the International Date Line -- Calendars: A Human Invention -- Glossary -- Learn More -- Index -- Back Cover.