Forces can't be seen, but without them, nothing around us would happen! A force is a push or pull that usually causes movement. Friction is a force that opposes motion and slows things down or stops them. Famous scientist and mathematician Sir Isaac Newton wrote the rules about forces and motion.
British scientist Robert Hooke built an early microscope and was the first scientist to observe cells and give them their name. Anton van Leeuwenhoek created the best microscopes of his time and used them to study living organisms. Matthias Schleiden, Theodor Schwann, and Rudolf Virchow created Cell Theory, which says that all living things are made of cells; cells are the smallest part of a living thing; and all cells come from other cells.
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.
Readers learn all about tropical and temperate rainforests and the differences between these two unique biomes. Rainforests are filled with wonder and mystery, from the tall trees in the canopy to the dark and damp leaves on the forest floor. The plants and animals that inhabit these rainforests are varied and exotic. They depend on the rainforest, as does the rest of the world.
A guide to what a wind turbine services technician does and how to become one.
Introduces readers to the cool career of wildlife photographer by giving a better understanding of this cool job.
Take a trip to the place where cows and horses play and fields of crops grow in this nonfiction book that tours a farm! Early elementary readers will discover the types of farm animals, crops, and different machinery used to run a farm. With informational text, a picture glossary, a map of the farm, and bright, colorful photos, readers will want to learn all about life on a farm!