دانلود کتاب محاسبات آسمانی

Although space travel on a limited scale is an accomplished fact, we are presently an Earthbound race whose minds yearn to explore the cosmos. Per- haps well before the end of this century some lucky explorers will have visited Mars or some other planet within our Solar System. Unfortunately, most of us will have to be content with imaginary journeys. This book is dedicated to all of us “armchair explorers” who look up into the night sky and are filled with curiosity and a burning desire to understand a little better how the universe in which we live appears to operate. Accordingly, this book was not written by a professional or even by an amateur astronomer, but rather it was written from the perspective of an amateur “amateur astronomer.” This book is most especially dedicated to Mom and Dad for all your years of encouragement and sacrifice. Because you rescued my brothers and me, I know the great debt I owe and can only offer only gratitude in return. Mary Ann, as always, your steadfast support has been the single most important factor contributing to the completion of this project. David, what would you have thought about the amazing universe in which we live?