1 ASTRONOMY 103ASTRONOMY 103The Evolving UniverseThe Evolving UniverseProfessor: Andy Sheinis [email protected]: 5520 Sterling HallPhone: 262-0492Office Hours: Tu 2pm-3pm, Wed 3pm-4pmTA: Ella Braden [email protected]: 4514 Sterling HallPhone: (608) 265-2554Office Hours:Monday: 11:45-1:15Wednesday: 11:00-12:30Thursday: 1:45-3:15Friday: 11:00-12:30Sunday 8:00-9:00pm online office hour ASTRONOMY 103ASTRONOMY 103The Evolving UniverseThe Evolving UniverseText: "Pathways to Astronomy" Schneider and Arny, McGraw-Hill (withthe clickers and Starrynight observing program).Clickers: We will use the clickers for this class. Clickers are availablewith the text or separately at the UW Bookstore. They must beregistered online at www.einstruction.com before you can use them inclass. The registration code for the class is Class Key:F37866N695. Directions for registering the clickers areattached as well as a tutorial.Website: http://www.astro.wisc.edu/~sheinis/103course.htmSee the website for HW assignments, solutions and interesting astronomy2 ASTRONOMY 103ASTRONOMY 103The Evolving UniverseThe Evolving UniverseGrading:2 midterms 20%+20%Homework 15%Labs 5%Quizzes (in Lecture) 10%Participation (clickers + section) 5%Final: 25% ASTRONOMY 103ASTRONOMY 103The Evolving UniverseThe Evolving UniverseEXAMS: Two (2) mid-terms and one (1) final exam will be given. All examsconsist of multiple-choice questions based on material covered inlectures and readings. Some questions may be based on the assignedweb-based reading reviewed in discussion sections.NO EXAMS CAN BE DROPPED. NO MAKEUP TESTS are given for examsexcept in the case of arrangements made at least 2 weeks in advanceof the exam, or for medical emergencies documented by a physician'snote.Focus of Exams: concepts not memorizing- like in-class quiz questions.- focus on lecture material and DEMOS!!3 ASTRONOMY 103ASTRONOMY 103The Evolving UniverseThe Evolving UniverseHonors:Honors credit for this course will be awarded on the basis of thesuccessful completion of the following:1. Written notification from the student to the instructor indicating thestudent will be taking the course for honors credit. This notificationmust be provided before the end of 2nd week of classes.2. A final grade of AB or better in the course.3. A project or research paper to be defined by the student inconsultation with the instructor. The student will contact theinstructor to set up appointment(s), nominally during the instructor'soffice hours. Please --Please --Homework:Goal is to solve on your own.Work together when stuck, butplease don't copy, or allow others to copy.Feel free to see/contact me for help.Goal is to show understanding:Show your work,explain specifically how you would get the answer if stuck.Any work:Give credit to sources of info where due(don't need to cite the text)4 Also --Also --Due dates:Please hand in work in classwhen due.(10%)=1 grade penalty/day of latenesswithout prior arrangementsExam and lab dates:Make prior arrangements forscheduling problems! Lecture outlineLecture outline1) 10-15 minute lecture on textbook unit2) Pose a question/answer via clickers3) Small group discussion4) Repose question5) Discuss answer(s)6) Repeat 1-55 IntroductionsIntroductions…… AstrophysicsAstrophysics Universe is the Xtreme physics lab:GravityGeneral relativityAtomic physicsAmazing things: black holes, neutron starssupernova explosionsgravitational lensesnebulaeaccretion disks, relativistic jets(and planets)6 Ask QuestionsWhen did the Universe begin?Do black holes really exist?What makes stars shine?Do stars ever die?What is at the edge of the universe?Is there an edge?Why are the most distant objects in the universe sodifferent from objects nearby?How do we know they are different?How do we know they are far away? Course outlineCourse outlinewill use the book but skipwill use the book but skiparoundaroundPart 1: Astronomical Framework (8 Lectures)Part 2: Stars and Stellar Evolution (9 Lectures)Part 3: Milkyway and Galaxies (8 Lectures)Part 4: Cosmology and Life in the U. (4 Lect)7 What isSCIENCE ??The Scientific MethodThe Scientific MethodThe Scientific Method is theprocedure scientists use toconstruct their ideas about howthe Universe works.Start with a hypothesis – a testableidea of how something worksTest the hypothesis!If the test fails, modify or abandonthe hypothesis, and retest.Hypotheses that pass many years oftesting become Laws(mathematical) or Theories(described using words).A Model is a complexdescription of physicalphenomena incorporatingmany laws and/ortheoriesEx: The Celestial SphereEx: Universal Gravitation8HypothothesisTheory or LawTests/observations Models/predictionsFacts/observablesWhy is it impossible toWhy is it impossible toprove a theory?prove a theory?A theory is not a fact. Only facts can be proven.* A theory is only supported by observations, a singlecontrary observation can disprove it.Theories can be proven! Once it is proven it is called afact.It is not possible for humans to observe evrything aboutthe universe, if they could they could prove atheory. (this one can also be argued as true)9 Astrologyvs Astronomyvs Astrophysics ?? The EarthThe EarthThe Earth is a planet, a bodyin orbit around a star (TheSun)Radius: 6371 km (3909miles)Mass: around 6 billiontrillion tonsActual value:5,970,000,000,000,000,000,000,000 kgToo many zeros!Use 5.97 × 1027 kg, instead!Metric System•Easier to use (everything is a factor of 10!)•More in Unit 3…10 The MoonThe MoonThe Moon is a satellite, abody orbiting a planetRocky world, littered withcratersBombarded by meteorsWhere are the Earth’scraters?Smaller than the EarthLess than 1/80 the mass¼ the diameter of EarthSmall, so cooled quickly!Cold, airless and lifeless Why is the moon so cratered, while the Earth is not?The Moon is older and hence hasn’t been impacted asmuch.The Moon protects the Earth from meteors since it’sorbit surrounds the Earth.The Earth has an atmosphere which protects it againstsmaller meteors. The Earth has erosion which hides the evidence ofimpacts.The Earth does have as many craters, we just don’t seethem due to oceans and plants.11 The scale of things (reduced 1:10 billion)The scale of things (reduced 1:10 billion)140mm(14 cm)Mars0.7mm23mVenus1.2mm11mEarth1.3mm15mJupiter14.3mm78mSaturn12mm143mUranus5.2mm287mNeptune4.8mm450mPluto0.2mm590mMercury0.5mm6mAsteroid BeltScale Models of the UniverseScale Models of the Universe