Quick Answer
The position of the sun changes throughout the year due to the Earth's tilt and orbit, resulting in varying solar angles and shadows. This change is essential for navigation, as it can be used to determine direction, time, and location. Shadow stick techniques can help track these changes.
Understanding the Earth’s Tilt
The Earth’s axis is tilted at approximately 23.5 degrees relative to its orbital plane around the sun. As the Earth orbits the sun, different parts of the planet experience varying amounts of sunlight throughout the year. This tilt causes the sun’s apparent position in the sky to change, resulting in different solar angles and shadow patterns.
Using a Shadow Stick for Navigation
A shadow stick is a simple tool used for navigation by measuring the length and direction of shadows. To use a shadow stick, find a straight stick or object and mark its end with a small rock or stick. At a known time (e.g., solar noon), mark the end of the shadow. As the sun moves, the shadow will also move. By measuring the angle between the stick and the shadow, you can estimate the time of day and direction of south.
Tracking the Sun’s Movement
To track the sun’s movement, observe the shadow stick over a period of time. Note the changes in the shadow’s length and direction. In the northern hemisphere, the sun rises in the east and sets in the west, with the shadow of the stick moving in a counterclockwise direction. As the seasons change, the sun’s apparent position in the sky will shift, and the shadow stick’s shadow will reflect this movement. By paying attention to these changes, you can estimate the time of year and use the shadow stick as a crude sundial.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.