Final answer:
Measurements of an object's shadow changing throughout the day provide evidence of the sun's changing position in the sky. This phenomenon is due to Earth's rotation and orbital motion, which was historically used by astronomers like Hipparchus to understand celestial mechanics.
Step-by-step explanation:
Data showing the length and direction of an object's shadow changing at different times of the day provides evidence that the sun is changing position in the sky throughout the day. These changes are due to the fact the Earth is rotating on its axis and orbiting around the sun. As Earth rotates, the sun's position in our sky changes, resulting in varying shadow lengths and directions. In the morning, shadows are long because the sun is low in the sky; at midday, shadows are short because the sun is high overhead; in the evening, shadows lengthen again.
Hipparchus utilized the shadows cast by the Earth on the moon during lunar eclipses to deduce the sun's position among the stars. Likewise, historical observations show that the points of sunrise and sunset shift, corroborating the understanding that the sun's path in the sky changes throughout the year. Consequently, daylight hours increase during summer and decrease in winter as the angle and duration of sun exposure change.
These observations help in understanding the movement of celestial bodies and our position relative to them, grounding the principles of modern astronomy. The changing shadows are a practical application of these underlying astrophysical principles, observable in everyday life.