...What is interstellar travel? Interstellar space travel is manned or unmanned space travel between different star systems, in comparison with space travel to other bodies in the same star system. It is invariably more difficult, as the time and distance scale for such an endeavour is almost unimaginable Why we want to visit other stars? The group identified five key factors as high-level motivations for the exploration of distant space: • Human survival: ideas related to creating a legacy for the human species, backing up the Earth’s biosphere, and enabling long-term survival in the face of catastrophic disasters on Earth. • Contact with other life: finding answers to whether there is other life in the universe, whether “intelligent” life exists elsewhere in the galaxy, and at a basic level, whether we are alone in the universe. • Evolution of the human species: exploration as a human imperative, expansion of human understanding and consciousness through space exploration. • Scientific discovery: breakthroughs in scientific understanding of the natural universe, a pursuit for knowledge. • Belief and faith: a search for God or the Divine, a need to explore beyond Earth’s atmosphere as a part of natural theology or as found through religious revelation. These drivers for exploration were identified through group discussion as the most significant, high-level reasons why human societies and individuals would undertake the exploration of space over long timescales...
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...Advertisement. EnchantedLearning.com is a user-supported site. As a bonus, site members have access to a banner-ad-free version of the site, with print-friendly pages. Click here to learn more. | (Already a member? Click here.) Our subscribers' grade-level estimate for this page: 4th - 5th | Table of Contents | Enchanted Learning All About Astronomy | Site Index | Our Solar System | Stars | Glossary | Printables, Worksheets, and Activities | The Sun | The Planets | The Moon | Asteroids | Kuiper Belt | Comets | Meteors | | Astronomers | | The Stars | Lifecycle | Nuclear Fusion | Brightest Stars | Galaxies | Other Solar Systems | Constellations | Why Stars Twinkle | Birth | Death | Star Types | Closest Stars | Nebulae | Major Stars | The Zodiac | Activities, Links | STARS Each star in the sky is an enormous glowing ball of gas. Our sun is a medium-sized star. Stars can live for billions of years. A star is born when an enormous cloud of hydrogen gas collapses until it is hot enough to burn nuclear fuel (producing tremendous amounts heat and radiation). As the nuclear fuel runs out (in about 5 billion years), the star expands and the core contracts, becoming a giant star which eventually explodes and turns into a dim, cool object (a black dwarf, neutron star, or black hole, depending on its initial mass). The largest stars have the shortest life span (still billions of years); more massive stars burn hotter and faster than their smaller...
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...To Know, or Not to Know: That is the Question Phillip Nelson Upper Iowa University Abstract Carl Sagan has a way of explaining very complex scientific facts and theories on a layperson level. In demonstrating that it is possible and desirable to know the universe, Sagan fails to address what it means to really “know” the universe in his essay titled Can We Know the Universe? Reflections on a Grain of Salt. The word “know” is an action verb with both transitive and intransitive meanings. It is the intransitive form that lacks explanation. Science can explain the “how” and the “why,” but it cannot bring meaning to either. Science and faith are both required for a complete picture of the universe. To Know, or Not to Know: That is the Question I have been a student of Carl Sagan since my youth. His way of explaining very complex scientific facts and theories spoke at my level. I can still remember how he compared human civilization to the age of the universe: if the age of the universe were a 12-month calendar year, recorded human civilization would be represented as the last 10-seconds of that year. Wow! I could get my brain around that idea. This seemed to be the answer to all the science, mathematics, and English questions I had as a high school student trying to make sense of it all. Once again Carl Sagan applies his ability to bring the very complex to the level of the average junior scientist in his paper titled Can We Know The Universe? Reflections...
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...Polynomials: Operations 4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 Integers as Exponents Exponents and Scientific Notation Introduction to Polynomials Addition and Subtraction of Polynomials Multiplication of Polynomials Special Products Operations with Polynomials in Several Variables Division of Polynomials Real-World Application Total revenue of NASCAR (National Association of Stock Car Automobile Racing) is expected to be $3423 million by 2006. Convert this number to scientific notation. Source: NASCAR This problem appears as Exercise 64 in Section 4.2. ISBN:0-536-47742-6 Introductory and Intermediate Algebra, Third Edition, by Marvin L.Bittinger and Judith A.Beecher.Published by Addison Wesley. Copyright ©2007 by Pearson Education, Inc. Objectives Tell the meaning of exponential notation. Evaluate exponential expressions with exponents of 0 and 1. Evaluate algebraic expressions containing exponents. Use the product rule to multiply exponential expressions with like bases. Use the quotient rule to divide exponential expressions with like bases. Express an exponential expression involving negative exponents with positive exponents. 4.1 a a a a INTEGERS AS EXPONENTS Exponential Notation An exponent of 2 or greater tells how many times the base is used as a factor. For example, a 4. In this case, the exponent is 4 and the base is a. An expression for a power is called exponential notation. an This is the exponent. This is the base. EXAMPLE 1 What is...
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...Chicago | San Francisco | Lisbon London | Madrid | Mexico City | Milan | New Delhi San Juan | Seoul | Singapore | Sydney | Toronto Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Manufactured in the United States of America. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher. 0-07-151120-2 The material in this eBook also appears in the print version of this title: 0-07-149340-9. All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after every occurrence of a trademarked name, we use names in an editorial fashion only, and to the benefit of the trademark owner, with no intention of infringement of the trademark. Where such designations appear in this book, they have been printed with initial caps. McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales promotions, or for use in corporate training programs. For more information, please contact George Hoare, Special Sales, at george_hoare@mcgraw-hill.com or (212) 904-4069. TERMS OF USE This is a copyrighted work and The McGraw-Hill Companies, Inc. (“McGraw-Hill”) and its licensors reserve all rights in and to the work. Use of this work is subject to these terms. Except as permitted under the Copyright Act of 1976 and the right...
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...fourth EDItION Critical Thinking A student ' s Introduction Ba ssha m I I rwi n I N ardon e I Wal l ac e CRITICAL THINKING A STUDENT’S INTRODUCTION FOURTH EDITION Gregory Bassham William Irwin Henry Nardone James M. Wallace King’s College TM TM Published by McGraw-Hill, an imprint of The McGraw-Hill Companies, Inc., 1221 Avenue of the Americas, New York, NY 10020. Copyright © 2011, 2008, 2005, 2002. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of The McGraw-Hill Companies, Inc., including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance learning. This book is printed on acid-free paper. 1 2 3 4 5 6 7 8 9 0 DOC/DOC 0 ISBN: 978-0-07-340743-2 MHID: 0-07-340743-7 Vice President, Editorial: Michael Ryan Director, Editorial: Beth Mejia Sponsoring Editor: Mark Georgiev Marketing Manager: Pam Cooper Managing Editor: Nicole Bridge Developmental Editor: Phil Butcher Project Manager: Lindsay Burt Manuscript Editor: Maura P. Brown Design Manager: Margarite Reynolds Cover Designer: Laurie Entringer Production Supervisor: Louis Swaim Composition: 11/12.5 Bembo by MPS Limited, A Macmillan Company Printing: 45# New Era Matte, R. R. Donnelley & Sons Cover Image: © Brand X/JupiterImages Credits: The credits section for this book begins on page C-1 and is considered...
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...reorganized discussion of evaluating Internet sources. Critical Thinking thinking, using real-world examples and a proven step-by-step approach. A student ' s Introduction A student's Introduction everyday culture and critical thinking. It covers all the basics of critical Critical Thinking Ba ssha m I Irwin I Nardone I Wall ace CRITICAL THINKING A STUDENT’S INTRODUCTION FOURTH EDITION Gregory Bassham William Irwin Henry Nardone James M. Wallace King’s College TM bas07437_fm_i-xvi.indd i 11/24/09 9:53:56 AM TM Published by McGraw-Hill, an imprint of The McGraw-Hill Companies, Inc., 1221 Avenue of the Americas, New York, NY 10020. Copyright © 2011, 2008, 2005, 2002. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of The McGraw-Hill Companies, Inc., including, but not limited to, in...
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