Quick Answer
Shadows can indeed help determine true north, but only if the sun's position is known and accounted for. This method relies on understanding the sun's path across the sky and using shadows to estimate its position. With practice, it can be a reliable technique for wilderness navigation.
Understanding the Sun’s Path
To use shadows for directional finding, you need to know the sun’s position in the sky at a given time. The sun moves approximately 15 degrees eastward every hour, and at its peak, it will be due south. By observing the shadow of an object, you can estimate the time of day and the direction of south. For example, if the sun is at its peak (due south) at noon, its shadow will be at its shortest length.
Measuring Shadows
To measure shadows, find a straight stick or object and stick it in the ground. Mark the end of the shadow with a small rock. Wait for a short period of time (about 15-30 minutes) and mark the new end of the shadow. The angle between the two marks is roughly 15 degrees, which is the sun’s rate of movement across the sky. By using a protractor or a piece of string to measure this angle, you can determine the approximate direction of south.
Practical Application
To use shadows to find true north, you need to determine south first. Once you have south, you can use your compass or a natural feature like a landmark to find north. This method is most effective when the sun is high in the sky (between 9 am and 3 pm), and the air is clear of any obstructions that might affect the shadow’s accuracy. Practice this technique in different environments and conditions to develop your skills and build confidence in using shadows for directional finding.
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