Astronomy Today

Download or read online book entitled Astronomy Today written by Eric Chaisson and published by Benjamin-Cummings Publishing Company. This book was released on 09 May 2021 with total page 761 pages. Available in PDF, EPUB and Kindle. Get best books that you want by click Get Book Button and Read as many books as you like. Book Excerpt : Astronomy is a science that thrives on new discoveries. Fueled by new technologies and novel theoretical insights, the study of the cosmos continues to change our understanding of the universe. We are pleased to have the opportunity to present in this book a representative sample of the known facts, evolving ideas, and frontier discoveries in astronomy today. Astronomy Todayhas been written for students who have taken no previous college science courses and who will likely not major in physics or astronomy. It is intended for use in a one- or two-semester, non-technical astronomy course. We present a broad view of astronomy, straightforwardly descriptive and without complex mathematics. The absence of sophisticated mathematics, however, in no way prevents discussion of important concepts. Rather, we rely on qualitative reasoning as well as analogies with objects and phenomena familiar to the student to explain the complexities of the subject without oversimplification. We have tried to communicate the excitement we feel about astronomy and to awaken students to the marvelous universe around us. Many of you—teachers and students alike—have given us helpful feedback and constructive criticism on earlier editions. From these, we have learned to communicate better both the fundamentals and the excitement of astronomy. Many improvements inspired by your comments have been incorporated into this new edition. Focus of the Fifth Edition From the first edition, we have tried to meet the challenge of writing a book that is both accurate and approachable. To the student, astronomy sometimes seems like a long list of unfamiliar terms to be memorized and repeated. You will indeed be introduced to many new terms and concepts in this course, but we hope you will also learn and remember how science is done, how the universe works, and how things are connected. In the fifth edition, we have taken particular care to try to show how astronomers know what they know, and to highlight both the scientific principles underlying their work and the process used in discovery. New and Revised Material Astronomy is a rapidly evolving field, and the three years since the publication of the fourth edition ofAstronomy Todayhave seen many new discoveries covering the entire spectrum of astronomical research. Almost every chapter in the fifth edition has been substantially updated with new information. Several chapters have also seen significant internal reorganization in order to streamline the overall presentation, strengthen our focus on the process of science, and reflect new understanding and emphases in contemporary astronomy. Among the many changes are: Expanded coverage throughout of the scientific method and how astronomers "know what they know." New part-opening essays to establish historical context for each section of the text. Updated material in Chapter 5 on adaptive optics, Keck, Subaru, Gemini, and the VLT; additional material on infrared and optical interferometry; new coverage of theChandraandSpitzermissions. An introduction to solar-system formation in Chapter 6, to better frame the discussion of planetary properties that follows. New material in Chapter 7 on the Ozone Hole and Global Warming. Expanded coverage in Chapters 6 and 10 of the most recent missions to Mars. Updates in Chapter 10 on Martian oppositions, gullies, oceans, and ice. Final update on theGalileo/GEMmission in Chapter 11. Coverage ofStardust,new Kuiper belt objects, and Pluto's status as a planet in Chapter 14. Updated discussion of solar system formation in Chapter 15; expanded coverage of competing theories, planet migration, planetesimal ejection, plutinos, and the angular momentum problem. New sections in Chapter 15 on extrasolar planets, with updated material on the latest observations and their implications for the condensation theory of solar system formation. Reorganization of presentation in Chapter 16, and an update on neutrino oscillations. New information on star names and revised coverage of key concepts in Chapter 17. Consistent and up-to-date stellar properties in Examples throughout Part 3. Updated information in Chapter 19 on brown dwarfs; new material on competitive accretion and collisions in star formation. New coverage in Chapter 20 of the end-states of stellar and binary evolution; more examples of familiar stars in specific evolutionary stages. Updated coverage of pulsars and gamma-ray bursts in Chapter 22. Reorganized and expanded material in Chapter 22 on Special and General Relativity and their historical development. Latest results in Chapter 23 on Sgr A* and the Galaxy's central black hole. Reorganization of Chapters 24 and 25, updating all coverage, emphasizing the connection between normal and a active galaxies, and expanding the discussion of black holes in galactic nuclei. Updated discussion in Chapter 24 of the measurement of Hubble's constant. Expanded and substantially revised coverage in Chapter 25 of galaxy collisions, hierarchical merging and galaxy evolution; revised discussion of active galaxy evolution. Consistent distances and times in Chapters 24-27, assuming a flat universe with dark matter and dark energy as determined by the WMAP satellite; incorporation of results from recent sky surveys. Extensive revision of Chapters 26 and 27 to include the most recent observations of cosmic acceleration and discussion of "dark energy." Revised discussions of the cosmological constant and the age of the universe; results from the CBI and 97AMP experiments suggesting a flat universe. Updated coverage of Europa, Mars, interstellar organic molecules, extrasolar planets, and SETI in Chapter 28. Expanded Glossary which now includes many additional terms used in the text, but not identified explicitly as keywords. New detailed Seasonal Star Charts, courtesy ofAstronomyMagazine. Compound Art.It is rare that a single image, be it a photograph or an artist's conception, can capture all aspects of a complex subject. Wherever possible, multiple-part figures are used in an attempt to convey the greatest amount of information in the most vivid way: Visible images are often presented along with their counterparts captured at other wavelengths. Interpretive line drawings are often superimposed on or juxtaposed with real astronomical photographs, helping students to really "see" what the photographs reveal. Breakouts—often multiple ones—are used to zoom in from widefield shots to closeups so that detailed images can be understood in their larger context. The Illustration Program Visualization plays an important role in both the teaching and the practice of astronomy, and we continue to place strong emphasis on this aspect of our book. We have tried to combine aesthetic beauty with scientific accuracy in the artist's conceptions that adorn the text, and we have sought to present the best and latest imagery of a wide range of cosmic objects. Each illustration has been carefully crafted to enhance student learning; each is pedagogically sound and tied tightly to the nearby discussion of important scientific facts and ideas. Full Spectrum Coverage and Spectrum Icons.Astronomers exploit the full range of the electromagnetic spectrum to gather information about the cosmos. Throughout this book, images taken at radio, infrared, ultraviolet, X-ray, or gamma-ray wavelengths are used to supplement visible-light images. As it is sometimes difficult (even for a professional) to tell at a glance which images are visible-light photographs and which are false-color images created with other wavelengths, each photo in the text is provided with an icon that identifies the wavelength of electromagnetic radiation used to capture the image and reinforces the connection between wavelength and radiation properties. Explanatory Captions.Students often review a chapter by "looking at the pictures." For this reason, the captions in this book are often a bit longer and more detailed than those in other texts. H-R Diagrams and Acetate Overlays.All of the book's H-R diagrams are drawn in a uniform format, using real data. In addition, a unique set of transparent acetate overlays dramatically demonstrates to students how the H-R diagram helps us to organize our information about the stars and track their evolutionary histories. Other Pedagogical Features As with many other parts of our text, instructors have helped guide us toward what is most helpful for effective student learning. With their assistance, we have revised both our in-chapter and end-of-chapter pedagogical apparatus to increase its utility to students. Learning Goals.Studies indicate that beginning students have trouble prioritizing textual material. For this reason, a few (typically 5 or 6) well-defined Learning Goals are provided at the start of each chapter. These help students structure their reading of the chapter and then test their mastery of key facts and concepts. The Goals are numbered and cross-referenced to key sections in the body of each chapter. This in-text highlighting of the most important aspects of the chapter also helps students review. The Goals are organized and phrased in such a way as to make them objectively testable, affording students a means of gauging their own progress. Concept Links.In astronomy, as in many scientific disciplines, almost every topic seems to have some bearing on almost every other. In particular, the connection between the astronomical material and the physical principles set forth early in the text is crucial. Practically everything in Chapters 6-28 of this text rests on the foundation laid in the first five chapters. For example, it is important that students, when they encounter the discussion of high-redshift objects in Chapter 25, recall not only what they just learned about Hubble's law in Chapter 24 but also refresh their memories, if necessary, about the inversesquare law (Chapter 17), stellar spectra (Chapter 4), and the Doppler shift (Chapter 3). Similarly, the discussions of the mass of binary-star components (Chapter 17) and of galactic rotation (Chapter 23) both depend on the discussion of Kepler's and Newton's laws in Chapter 2. Throughout, discussions of new astronomical objects and concepts rely heavily on comparison with topics introduced earlier in the text. We remind you of these links so you can recall the principles on which later discussions rest and, if necessary, review them. To this end, we have inserted "Concept Links" throughout the text—symbols that mark key intellectual bridges between material in different chapters. The links, denoted by the symbol together with a section reference, signal that the topic under discussion is related in some significant way to ideas developed earlier, and provide direction to material to review before proceeding. Key Terms.Like all subjects, astronomy has its own specialized vocabulary. To aid learning, the most important astronomical terms are boldfaced at their first appearance in the text. Each boldfaced Key Term is also incorporated in the appropriate chapter summary, together with the page number where it was defined. In addition, an expanded alphabetical glossary, defining each Key Term and locating its first use in the text, appears at the end of the book. Concept Checks.We incorporate into each chapter a number of "Concept Checks"-key questions that require the reader to reconsider some of the material just presented or attempt to place it into a broader context. Answers to these in-chapter questions are provided at the back of the book. End of Chapter Questions and Problems.Many elements of the end-of-chapter material have seen substantial reorganization: Each chapter now incorporates 20 Conceptual Self-Test Questions, equally divided between "true/false" and multiple choice formats, allowing students to assess their understanding of the chapter material. Answers to questions appear at the end of the book. Each chapter also has 20 Review and Discussion Questions, which may be used for in-class review or for assignment. As with the Self-Test Questions, the material needed to answer Review Questions maybe found within the chapter. The Discussion Questions explore particular topics more deeply, often asking for opinions, not lust facts. As with all discussions, these questions usually have no single "correct" answer. The end of chapter material includes 15 Problems, based on the chapter contents and entailing some numerical calculation. In many cases the problems are tied directly to quantitative statements made (but not worked out in detail) in the text. The solutions to the Problems are not contained verbatim within the chapter, but the information necessary to solve them has been presented in the text. Answers to odd-numbered Problems appear at the end of the book. Discovery Boxes.Exploring a wide variety of interesting supplementary topics, these features have been expanded and provide the reader with insight into how scientific knowledge evolves, and emphasizing our theme of the process of science. More Precisely Boxes.These provide more quantitative treatments of subjects discussed qualitatively in the text. Removing these more challenging topics from the main flow of the narrative and placing them within a separate modular element of the chapter design (so that they can be covered in class, assigned as supplementary material, or simply left as optional reading for those students who find them of interest) will allow instructors greater flexibility in setting the level of their coverage. Interactive eBook.TheAstronomy Today, Fifth Editioninteractive eBook is located in the WebCT, B1ackBoard, and OneKey courses and has been redesigned for easier and clearer navigation. It contains a full electronic version of the text, with key term hyperlinks and imbedded media elements at point of use. The eBook features: New!Tutorials: Written by Philip Langill (University of Calgary). These animated, interactive F1ash™files, denoted by an icon in the text, allow students to explore the ideas and concepts from the text in depth. Students are engaged in the thought process as they answer questions and change parameters in these exploratory activities. New! Physlet(tm)Illustrations for Astronomy: Written by Chuck Niederriter and Steve Mellema (both of Gustavus Adolphus College); Physlets by Wolfgang Christian (Davidson College). Through animation, these brief Java applets, denoted by an icon in the text, further illustrate concepts from the text. Each Physlet is followed by a series of questions that encourage students to think critically about the concept at hand. 61 narrated videos and animations imbedded within the text, at point of use. These help to bring text figures and concepts to life. All bold key terms in the text are hyperlinked to a glossary definition and an audio pronunciation. Student Accelerator CD-ROM.The Student Accelerator CD-ROM that is packaged withAstronomy Today, Fifth Editioncontains the Tutorials, Physlet(tm)Illustrations, animations, and videos from the eBook. The CD accelerates the performance of the eBook when students download the high-bandwidth media, so that students are not restricted by slow connections. It can also be used apart from the eBook if a student doesn't have a live Internet connection or just wants to view the media elements. Companion Website.(http://astro.prenhall.com/chaisson) The text-specific Companion Website forAstronomy Today, Fifth Editionorganizes material from a variety of sources on the web on a chapter-by-chapter basis, is updated regularly, and provides interactive exercises for each chapter. It includes: Annotated images, videos, and animations that are regularly updated to reflect the most recent astronomical discoveries. Interactive multiple-choice quizzes with hints and instant feedback. Algorithmically generated versions of the end-of-chapter problems from the text. Links to associated websites that are regularly updated for currency and relevancy.