Explores how human activity affects the Earth, e.g. effects of human activity on groundwater and surface water, habitat destruction, construction, emissions, and pollution.
What will houses look like in the future? From space stations to pod living, this innovative title examines how architects design and plan for the world of tomorrow. Readers put concepts to work when they design their own home based around a unique shape.
Ideal for students living in an urban area, colorful illustrations and humorous characters outline the steps needed to build towering homes. Building big and building up, students learn about problems and solutions encountered by engineers and architects.
Pulleys are simple machines used to lift and move loads. Builders use pulley systems to lift tools or materials. Elevators use pulleys to move up and down. Kids will learn how pulleys make work easier and how they are often part of complex machines. Blastoff! Series
Levers are simple machines that make work easier. There are three different classes of levers. Students will learn what levers are, how the classes of levers differ, and how the construction of levers makes work easier. Blastoff! Series
Alfred Wegener studied astronomy and meteorologyâ€”and was even a record-holding balloonistâ€”before he became famous for his theories on how the land and seas on Earth were formed and change. These ideas are continental drift and plate tectonics. Seeing that the continents fit together like a puzzle, Wegener proved the theory that all of Earth's continents were once connected. Although his theories weren't accepted until after his death, scientists use plate tectonics to explain volcanoes and many other changes on Earth.
Much of what we know today about Earth is from images taken by cameras on powerful telescopes. Edwin Hubble changed our view of the universe. Working in an observatory, he found that there are other galaxies besides the Milky Way. He also showed that the universe is still growing. Lyman Spitzer, Jr. proposed placing telescopes in space, and in 1990, the Hubble Space Telescope was launched. It sends us amazing images of the universe.