Explains the basic science of flight, the problems of getting vehicles into the air, different types of engines, and aircraft design. Includes instructions for making aircraft models.
For thousands of years, people have been fascinated by the night sky and the mysteries it holds. Since 17th-century astronomers built the first telescopes, scientific inventions, such as space probes and satellites, have allowed us to understand more and more about the vast universe that surrounds our planet. Yet despite all our efforts, there are still many mysterious to solve.
Examines the growing practice of altering genes for the purpose of curing disease and improving plants and animals, presenting both sides of this controversial issue.
