Evidence for the birth of the universe is raining down on you. It's called the cosmic microwave background, and it's had quite a journey. Born in the stupendous annihilation of matter and antimatter seconds after the big bang, trapped in the hot plasma of the expanding universe for 380,000 years, and then suddenly released when the universe cooled to the point that atoms could form, this echo of creation has been on an uninterrupted voyage through space for 13.7 billion years-until it reached you.
Evidence for the birth of the universe is raining down on you. It's called the cosmic microwave background, and it's had quite a journey. Born in the stupendous annihilation of matter and antimatter seconds after the big bang, trapped in the hot plasma of the expanding universe for 380,000 years, and then suddenly released when the universe cooled to the point that atoms could form, this echo of creation has been on an uninterrupted voyage through space for 13.7 billion years—until it reached you. The cosmic microwave background is just one of the many clues about the history and nature of our universe that make the science of cosmology a wondrous, fascinating, and philosophically profound field of study.
The story of Earth is an epic filled with crises, catastrophes, and remarkable, repeated change. Earth traces its origin to simple atoms that were created in the big bang, transformed into heavy elements in stellar explosions, and then forged into a planet inside the nebula that gave birth to the solar system. Like many other planets, Earth went through phases of melting, volcanism, and bombardment by asteroids. But only on Earth did events lead to a flourishing biosphere—life. And once life was established, it drove the evolution of our planet in startling new directions.
The scientific theories that were first discovered and made public in the years 1700-1900 are some of the most pivotal in history. Landmark theories of planetary motion, the workings of nature, and the speed of light were all ideas that took the world by storm.
It takes a certain amount of courage to step beyond one's day-to-day experiments and look at the big picture - and the origin of the Moon is a big picture question par excellence. Perhaps it makes sense that William Hartmann, one of the two scientists who unraveled the Moon's biggest mystery, is not only a scientist but also a part-time artist and science fiction writer. It took someone with an artist's eye and a fiction writer's speculative temperament to see the big picture.
This visually rich course is designed to provide a nontechnical description of modern astronomy, including the structure and evolution of planets, stars, galaxies, and the Universe as a whole. It includes almost all of the material in my first two astronomy courses for The Teaching Company, produced in 1998 and 2003, but with a large number of new images, diagrams, and animations. The discoveries reported in the 2003 course are integrated throughout these new lectures, and more recent findings (through mid-2006) are included, as well. Much has happened in astronomy during the past few years; we will discuss the most exciting and important advances.
Step outside at any time of day or night, look up, and you're bound to see a world filled with limitless wonders: majestic rainbows, dramatic cloud formations, stirring sunsets, intricate constellations, captivating solar eclipses, and even the distant planets themselves. But these and other breathtaking natural phenomena are more than just pretty objects to be admired.
We once thought ourselves to be at the center of the world, now we know that we are just a small spec in a giant universe.