Sun and Shade

This teacher's background gives teachers in-depth insight into the phenomenon the students will learn about. In this lesson, students build on their knowledge of temperature by carrying out an experiment to compare the effect of sunlight and shade on different Earth materials.

Earth has many different surfaces, including snow-covered land, forests, oceans, polar ice caps, and human-built cities and roads. Each surface absorbs heat differently and we can feel those differences by noticing the temperature variation. Picture the blacktop on a newly paved road on a hot summer day. Its dark color makes it a strong absorber, so little of the sun’s energy is reflected away. Instead, that energy is absorbed as thermal energy (heat). This causes the road to become hotter.

Lizards instinctively know that different kinds of surfaces absorb heat from the sun differently.

Lizards have to move from surface to surface to regulate their internal body temperature. Lizards and other reptiles rely on their external environment to keep their bodies at a stable temperature. This is different from humans and other animals, who can maintain a stable body temperature through internal body processes.

Shade is the area around an object where sunlight cannot reach. Shade is the darkness created by a shadow, which is a dark shape created when an object blocks light. Temperatures are cooler in the shade because the sun’s energy is not reaching that area directly. In the previous lesson, students investigate the temperature difference of materials in direct sunlight and those in the shade. In this lesson, students carry out an experiment to explore the relationship between the sun’s shining and temperatures by investigating the temperatures of different materials in the sun and in the shade.