In this video Paul Andersen describes the four major spheres on planet Earth. The geosphere makes up the mass of the planet and includes the major landforms. The hydrosphere is all of the water and the atmosphere is all of the gases. The biosphere exists where the others spheres interface. A K-12 teaching progression is also included.
In this video Paul Andersen explains how systems can be used to understand phenomenon in science and create better designs in engineering. He starts by defining the characteristics of a system and describes how system models can be used to better understand the world. For example a system model of the water cycle can show the cycling of matter on the surface of the Earth. He ends with a progression of instruction for a K-12 science classroom.
Paul Andersen explains the importance of modeling in science and engineering. Models are used by scientists to explain phenomenon. Unlike mental models, conceptual models can be shared by all scientists to improve our understanding of the Universe. Engineers use models study systems and test designs.