天文學(xué)英文版課件3

1、UniverseEighth EditionRoger A. Freedman William J. Kaufmann IIICHAPTER 1Astronomy and the UniverseHomework 1 Online quiz for Chapter 1 (see syllabus for URL)DUE Friday 9/3 by 5 PMBy reading this chapter, you will learn1-1 What distinguishes the methods of science from otherhuman activities1-2 How ex

2、ploring other planets provides insight into the origins of the solar system and the nature of our Earth1-3 Stars have a life cyclethey form, evolve over millions or billions of years, and die1-4 Stars are grouped into galaxies, which are found throughout the universe1-5 How astronomers measure the p

3、ositions and sizes of celestial objects1-6 How to express very large or very small numbers in convenient notation1-7 Why astronomers use different units to measure distances in space1-8 What astronomy can tell us about our place in the universeWhich of the following statements is true?A solar system

4、 may contain billions of stars.Stars are spread out more or less uniformly throughout the Universe.The Milky Way contains a variety of solar systems, stars, and galaxies.A galaxy contains billions of stars.A solar system contains billions of galaxies.Q1.13Which of the following statements is true?A

5、solar system may contain billions of stars.Stars are spread out more or less uniformly throughout the Universe.The Milky Way contains a variety of solar systems, stars, and galaxies.A galaxy contains billions of stars.A solar system contains billions of galaxies.Q1.13The separation between the two p

6、ointer stars of the Big Dipper is 5 degrees. What is this separation in arcminutes? 50 60300 50018,000Q1.4The separation between the two pointer stars of the Big Dipper is 5 degrees. What is this separation in arcminutes? 50 60300 50018,000A1.4What lengths are most conveniently measured in units of

7、nanometers (109 m)?Distances between the planetsDistances between cities on EarthDimensions of the human body Wavelengths of visible light Diameter of an atom Q1.6What lengths are most conveniently measured in units of nanometers (109 m)?Distances between the planetsDistances between cities on Earth

8、Dimensions of the human body Wavelengths of visible light Diameter of an atom A1.6What lengths are most conveniently measured in astronomical units (AU)?Distances on the Earth Distances within the solar system Distances between stars in our Galaxy Distances between galaxies Only the largest distance

9、s in the universe Q1.5What lengths are most conveniently measured in astronomical units (AU)?Distances on the Earth Distances within the solar system Distances between stars in our Galaxy Distances between galaxies Only the largest distances in the universe A1.5What is the approximate diameter of ou

10、r Galaxy, the Milky Way?50 106 km 50 astronomical units 50 light-years 50 kiloparsecs 10 million light-yearsQ1.8What is the approximate diameter of our Galaxy, the Milky Way?50 106 km 50 astronomical units 50 light-years 50 kiloparsecs 10 million light-yearsQ1.8Key IdeasAstronomy, Science, and the N

11、ature of the Universe: The universe is comprehensible. The scientific method is a procedure for formulating hypotheses about the universe. These are tested by observation or experimentation in order to build consistent models or theories that accurately describe phenomena in nature.Observations of t

12、he heavens have helped scientists discover some of the fundamental laws of physics. The laws of physics are in turn used by astronomers to interpret their observations.The Solar System: Exploration of the planets provides information about the origin and evolution of the solar system, as well as abo

13、ut the history and resources of Earth. Stars and Nebulae: Studying the stars and nebulae helps us learn about the origin and history of the Sun and the solar system.Galaxies: Observations of galaxies tell us about the origin and history of the universe.Angular Measure: Astronomers use angles to denote the positions and sizes of objects in the sky. The size of an angle is measured in degrees, arcminutes, and arcseconds.Powers-of-Ten Notation is a convenient shorthand system for writing numbers. It allows very large and very small numbers to be expressed in a compact form.Units of Dis