Category: Investigations

{ Population Growth Contents } { All GSS Books } This investigation involves a method of estimating the population size of grasshoppers and other animals. This activity is conducted outside in the fall, in an open field that will remain undisturbed for 1-2 weeks. We capture grasshoppers and mark them in a way that will […]

Chapter 2 { Population Growth Contents } Understanding the patterns of population change has become possible by creating mathematical models, or equations, that have the same characteristics as actual populations.  An equation that successfully models population growth must display some of the same patterns that we saw on Goat Island. Making a graph that is […]

Chapter 1 { Population Growth Contents } The word “population” can refer not only to people, but to groups of beetles, or cacti, or even fireflies!  A population is a group of individuals of one species living in an area and occupying a particular ecological niche. This book is about the impacts of populations on […]

POPULATION GROWTH addresses a fundamental problem: even if we can change our habits to use only clean and efficient sources of energy such as solar, wind, and water power, global environmental problems will continue to worsen if the world’s population continues to grow at the present rate. See Overview. Contents Chapters Investigations Stay Current 1. […]

{ Energy Use Contents } { All GSS Books } CONSTRUCTION 1. Make a parabolic curve template by drawing a parabola approximately 32″ (80 cm) wide with a focal length (f)  of about 8″ (20cm). You can plot a number of “x” and “y” points according to the following formula for a parabola: y = […]

{ Energy Use Contents } { All GSS Books } There are many types and designs of solar cookers. They all involve focusing a large area of light into a small region where the food is placed. In general, the sunlight is reflected into the food cooking chamber using inexpensive reflecting surfaces. The reflecting surfaces […]

Chapter 9 { Energy Use Contents } There’s an old song from the early days of automobiling. “Come away with me Lucille. In my merry Oldsmobile.”  You don’t know that one? How about this? “Oh Lord, won’t you buy me a Mercedes Benz?” No? Well you probably know some car song. After all, people in […]

Chapter 8 { Energy Use Contents } I. Controlling the Flow of Heat Keeping comfortable, or simply staying alive, requires a temperature that’s not too hot and not too cold. As warm-blooded creatures, we have a built-in system for heat control. As intelligent humans, we augment our built-in systems with technologies—clothing, housing, and fire—that enable […]

{ Energy Use Contents } { All GSS Books } Many types of lights can be found in a hardware store. There are energy-saver incandescent bulbs, fluorescent bulbs, long-life bulbs, low-cost light bulbs, LED lights and specialty lights of all kinds. Work with a team to examine a collection of light bulbs. Find the wattage printed […]

Chapter 7 { Energy Use Contents } The continental United States viewed from space at night reveals the tremendous amount of energy we use for lighting. Where is your hometown? An astronomical observatory near Tucson, Arizona, found the quality of its observing conditions seriously impaired by the street lights of a small neighboring community.  The […]