In this Thread, we will discover how a given amount of light changes in intensity when the area it shines on changes. We will also make a final observation about the change in light and heat that happens when we tilt towards or away from the Sun. This explains why things seem less warm during the winter months, when the section of Earth we live on is tilting away from the Sun. The National Science Education Standards call for our students to learn how the seasons happen. Vocabulary words we can introduce here to help us talk about our experiences are area, tilt, and intensity.
Light travels very directly, in straight lines.
And because light behaves both like a very direct wave and like traveling particles means that as light hits something, it transfers some of its energy to the surface of that thing. In this Thread we will discover that the amount of light that hits a certain spot can actually be reduced. This seems like it contradicts what we just said about light. The conservation of energy principles at work here can be compared to the act of making a peanut butter and jelly sandwich. Since we use that analogy in the Threads to think more about what we are seeing, the analogy has been reproduced here in the Teacher Background so that you don't have to search for it in the text of the Thread itself.