Dont Know Much About the Universe: Everything You Need to Know About Outer Space but Never Learned by Kenneth C. DavisWho dug those canals on Mars? What was the biblical Star of Bethlehem? Were the pyramids built by extraterrestrials?
From the ancients who charted the heavens to Star Trek, The X-Files, and Apollo 13, outer space has intrigued people through the ages. Yet most of us look up at the night sky and feel totally in the dark when it comes to the basic facts about the universe.
Kenneth C. Davis steps into that void with a lively and readable guide to the discoveries, theories, and real people who have shed light on the mysteries and wonders of the cosmos. Discover why Einstein was such a genius, the truth behind a blue moon or two, the amazing secrets of Stonehenge, and even how one great astronomer lost his nose.
With the fun question-and-answer format that has appealed to the millions of readers of his bestselling Dont Much About® series, youll be taking off on an exciting armchair exploration of the solar system, the Milky Way, and beyond.
Life in The Universe Documentary - HD 1080p
Beyond Our Solar System
Our Sun is one of at least billion stars in the Milky Way, a spiral galaxy about , light-years across. The stars are arranged in a pinwheel pattern with four major arms, and we live in one of them, about two-thirds of the way outward from the center. Most of the stars in our galaxy are thought to host their own families of planets. The universe is a vast expanse of space which contains all of everything in existence. The universe contains all of the galaxies , stars, and planets. The exact size of the universe is unknown. Scientists believe the universe is still expanding outward.
Story of the Universe
Access the image The Universe is everything we can touch, feel, sense, measure or detect. It includes living things, planets, stars, galaxies, dust clouds, light, and even time. Before the birth of the Universe, time, space and matter did not exist. The Universe contains billions of galaxies, each containing millions or billions of stars. The space between the stars and galaxies is largely empty.
All rights reserved. Galaxies are sprawling systems of dust, gas, dark matter , and anywhere from a million to a trillion stars that are held together by gravity. Nearly all large galaxies are thought to also contain supermassive black holes at their centers. The deeper we look into the cosmos, the more galaxies we see. One study estimated that the observable universe contains two trillion—or two million million—galaxies. Some of those distant systems are similar to our own Milky Way galaxy, while others are quite different. Since it is so far from us, it takes light from Andromeda more than 2.
The universe was born with the Big Bang as an unimaginably hot, dense point. When the universe was just 10 of a second or so old — that is, a hundredth of a billionth of a trillionth of a trillionth of a second in age — it experienced an incredible burst of expansion known as inflation, in which space itself expanded faster than the speed of light. During this period, the universe doubled in size at least 90 times, going from subatomic-sized to golf-ball-sized almost instantaneously. The work that goes into understanding the expanding universe comes from a combination of theoretical physics and direct observations by astronomers. However, in some cases astronomers have not been able to see direct evidence — such as the case of gravitational waves associated with the cosmic microwave background, the leftover radiation from the Big Bang. A preliminary announcement about finding these waves in was quickly retracted, after astronomers found the signal detected could be explained by dust in the Milky Way.