From the Big Bang to Planet X: The 50 Most-Asked Questions about the Universe ... And Their Answers - Softcover

Dickinson, Terence

Softcover

ISBN 10: 0921820712 ISBN 13: 9780921820710

Publisher: Camden House, 1993

Synopsis

What exactly is the Big Bang Theory?
How do we know the universe is expanding?
What is a black hole? Does a Planet X exist?
What came before the Big Bang?
How many galaxies are in the universe?

These are just six of the 50 questions answered in this fact-filled guide to the latest findings and theories in astronomy. Concise yet authoritative, it is the perfect reference for the thoughtful reader who doesn't have the luxury of time.

About this title

About the Author:

Terence Dickinson, one of North America's leading astronomy writers, has been asked just about every astronomy question there is. In this book, he has selected the 50 most-asked questions as a foundation from which to unravel the mysteries of the cosmos in the down-to-earth style that has made him a best-selling author with over one million books in print.

He has received many national and international science awards including the New York Academy of Sciences Book of the Year Award and the Royal Canadian Institute's Sandford Fleming Medal.

Excerpt. © Reprinted by permission. All rights reserved.:

Introduction

What came before the Big Bang? What is a black hole? Why do stars twinkle? Are UFOs real?

Who asks questions like these? You do.

How do I know? I have heard them asked many times. For more than 30 years, I have talked about astronomy in planetariums and on radio, written about the cosmos in books, magazines and newspapers and taught astronomy at college. Year after year, again and again, I am asked many of the same questions-or variations of them. The 50 most-asked questions are the basis for this book.

If you have ever gazed in wonderment at a star-filled sky on a cool summer night in the country or had your curiosity aroused by a brief television news item about an astronomical discovery, then this book is for you. You can jump in anywhere; the book is designed for browsing. It provides more depth than television can -- but never more than you can handle. And if you want to explore any of the subjects further, I have provided suggestions for in-depth reading for every question. Before you start, though, the following diversion should make the browsing easier.

Picture the interior of Toronto's huge retractable-roof stadium, the SkyDome, several hours before a baseball game. The seats are empty, and the grounds crew has taken a coffee break. At home plate rests the sun, the size of a baseball. The first four planets -- Mercury, Venus, Earth and Mars -- each about the size of a ball in a ballpoint pen, are, respectively, 1/8, 1/5, 1/3 and 1/2 of the way to the pitcher's mound. A pea near second base is Jupiter. In shallow center field is Saturn, a smaller pea. Uranus, the size of this letter O, is at the outfield fence. Neptune, another O, is well back in the outfield seats, while Pluto, the smallest planet and a mere grain of sand in our model, runs along the track that carries the dome's movable sections.

Between Mars and Jupiter, just inside the bases, are millions of bits of dust -- these are the asteroids. Ranging well beyond Pluto, out past the city limits, are trillions of comets, all so small that a microscope would be needed to see them. Back inside the dome, down in the artificial turf somewhere between home plate and the pitcher's mound, is the farthest humans have traveled: one thumb width, from Earth to the moon.

The utility of our model does not stop there. The nearest star, Alpha Centauri, can be included too, represented by another baseball, at another home plate -- in the Houston Astrodome.

Such perspectives make it clear why sending robot spacecraft to the planets orbiting our sun (which we have done, with the exception of Pluto) is completely different from dispatching vehicles to explore planets of other stars. Interstellar travel is a quantum leap in distance and technological difficulty, not to mention the travel time. A robot spacecraft trekking to Alpha Centauri at the same speed as today's fastest spacecraft would take 30,000 years to get there. Even travelling at 1 percent of the velocity of light, a speed enormously faster than any current technology can muster, the voyage would still take 430 years.

Alpha Centauri's distance is 41 trillion kilometers. Astronomers use a more convenient measure: 4.3 light-years. One light-year, the distance light travels in one year, is 9.46 trillion kilometers. The farthest star seen with the naked eye on a dark night is about 4,000 light-years from Earth. That's still well within our galaxy, the Milky Way, which is a flat disc- shaped city of several hundred billion stars about 85,000 light-years across.

The nearest galaxy like our own, the Andromeda Galaxy, is 2.2 million light-years away. There are an estimated 100 billion similar galaxies in the known universe. The most remote of them, more than 10 billion light-years from us, show up as faint oval smudges on photographs taken with the Hubble Space Telescope. If scaled-down versions of the Milky Way Galaxy and the Andromeda Galaxy were placed at either side of the sprawling city of Los Angeles, the distant galaxies seen by Hubble would be farther away than the moon.

This immensity, the mind-stretching vastness of the universe, means that it can never be fully explored in all its detail. The universes estimated cargo of a billion trillion stars is so over whelming that just trying to count them, at the rate of one per second, would require 500 billion human life spans. It would be the equivalent of counting all the grains of sand on all the Earth's beaches.

Yet as Einstein once said: "The most incomprehensible thing about the universe is that it is comprehensible." We do know an enormous amountabout the cosmos and our place in it -- just enough to begin to ask the big questions.

Terence Dickinson

About this edition

• Publisher: Camden House
• Publication date: 1993
• ISBN 10: 0921820712
• ISBN 13: 9780921820710
• Binding: Paperback
• Number of pages: 152