How is a shadow formed and why does it change shape? - Teacher notes

Shadows are a common phenomenon that occur when an opaque object obstructs light, preventing it from passing through. In educational settings, students are often encouraged to conduct experiments to observe when shadows are longer or shorter, which helps them understand the principles of light and shadow formation. By setting up simple experiments with a light source and an object, pupils can record the length of shadows at different times of the day, and then create diagrams to illustrate their findings. This process demonstrates that shadows change length due to the angle at which sunlight or another light source hits the object, with the longest shadows occurring when the sun is low in the sky, such as during the early morning or late afternoon.

Understanding light and dark, as well as their effects on everyday life, is another aspect of learning about shadows. Students can explore this concept through creative activities, such as creating hand shadows. By casting hand shadows onto a wall using a focused light source, they can see firsthand how the shape and size of a shadow can be manipulated by changing the position of their hands relative to the light. Documenting these attempts with photographs allows students to reflect on how light interacts with objects to create varying silhouettes. This understanding of light and dark informs not only scientific knowledge but also the appreciation of how these elements impact daily activities, work, and even art.