ASTR100 (Spring 2008)
Introduction to Astronomy
Prof. D.C. Richardson
Sections 0101-0106
Astronomy 100 – ASTR100
Professor:
Dr. Derek C. Richardson
Phone:
301-405-8786
E-mail:
dcr@astro.umd.edu
Office:
CSS 1249
Office Hours: W 11h-12h, or by appointment.
Course web page: http://elms.umd.edu/
Textbook: The Essential Cosmic Perspective
(4th ed, Media Update), Bennett et al.
Textbook web page: http://masteringastronomy.com/
What is astronomy?
 The observation and study of everything in
the universe except the Earth (but we’ll talk
about the Earth too – it’s the best
understood planet).
 Oldest of all the sciences – but we’ll be
talking about “modern” astronomy.
What is astrophysics?
 Application of physical laws to understand
celestial objects.
The Earth
The Moon
Artist’s view of the Solar System
Stars & Gas
© Anglo-Australian Telescope Board (http://WWW.AAO.GOV.AU/images.html)
Artist’s view of our Galaxy
Remote Galaxies seen by HST
An atom (helium)
Basic logistics, organization,
expectations and rules of the
course…
Course syllabus and lecture plan
 Log in to ELMS/Blackboard:
 http://elms.umd.edu/
 READ THE SYLLABUS!
 The syllabus is our mutual contract.
 Complete the ASTR100 Contract quiz
online (click on the “Homework” button to
see it).
Class web page
 Announcements
 Syllabus
 Lecture plan
 Homework
 Extra stuff to help you out
 MasteringAstronomy.com
 Cool links
 NOTE: Each discussion section also has
its own ELMS course page!
 You can check your grade there.
Discussion Sections (CSS 2400)
Section First Meeting
Time
9:00 am
TA Name
0101
Mon Feb 4
Michael McDonald
0102
Mon Feb 4
0103
Mon Feb 4
noon
0104
Wed Feb 6
9:00 am
Naomi Luis
0105
Fri Feb 8
9:00 am
Naomi Luis
0106
Fri Feb 8
noon
Ashley King
10:00 am Michael McDonald
Matthew Zagursky
Meet in CSS 2400 (newer wing of CSS building)
Map for sections
Sections
meet here
We are here
The Computer and Space Sciences
building is a confusing labyrinth!
CSS (Computer & Space Sciences bldg)
2400 is in the NEWER wing of CSS…
Older wing of CSS is 60’s-era brick building
(my office, TA offices).
Newer wing of CSS is 90’s-era glass-faced
building just up hill from older CSS wing.
Go up one floor from entrance floor.
CSS 2400 is entered from near atrium.
This is a CORE course…
 This course is intended for non-science majors.
 No more than modest high-school science and math
required.
 This course satisfies CORE Distributive Studies
requirement for a non-lab physical science
course (Code PS).
 For a lab physical science course (PL):
 You MUST take ASTR 111 simultaneously with this
course, OR take ASTR 101 instead of this course.
 You cannot get credit for both ASTR 100 and
ASTR 101.
Lectures
 Provide a framework for reading,
homework, discussion sections.
 Not a substitute for anything above!
 Based on material in the book, but
expands on some things, skips others.
 Demonstrations of basic principles.
 Notetaking: don’t concentrate on details
(those are in the book), just on the
broader connections.
Course Expectations
 Attendance
 Attend all lectures and discussion sections!
 Significant grade is awarded for
participation and activities in discussion
sections.
 Exams and homework are based on
lectures, textbook, and discussion sections.
 There will be unannounced in-class
exercises.
 If you have to miss a class, borrow notes
from other students.
Course Expectations
 Preparation
 Be prepared (see schedule)…
 Preview reading assignment before class.
 Read it again more carefully after class.
 Study your class notes after class…
 Ask questions!
 Don’t fall behind, don’t cram.
 Talk to TA or prof before you get in trouble.
 That’s what office hours are for!
 Take advantage of them!
Course Expectations
 Mathematics and physics
 Modern astrophysics is as technical as it
gets… there is lots of very hard math and
physics!
 We will avoid the really technical stuff, but
there will be high-school level math
(algebra & geometry).
 Expect it! If you get stuck, ask for help
before you fall behind!
Grading: weights
Component
Points
Homework
130
Discussion section
130
In-class exercises
20
Midterm exam 1
75
Midterm exam 2
75
Final exam
120
TOTAL
550
Grading: boundaries
Letter grade
Percentage
Points
A-, A, A+
90-100+%
495-550+
B-, B, B+
C-, C, C+
D-, D, D+
80-90%
70-80%
60-70%
440-494
385-439
330-384
F
0-60%
0-329
 The optional plus/minus grading system
will be used in this course.
 Any adjustment to boundaries will be to
lower percentages, never to raise them.
Midterms and final exam
 Midterms (both in class, in this room):
1. Tuesday, March 4.
2. Tuesday, April 15.
 Cumulative final exam (in this room):
 Friday, May 16, 8 am-10 am.
 Midterms and Final:
 Cover lecture, textbook, discussion section.
 Closed book, no notes or calculators, no
walkmans, no mobile phones, no PDAs, etc.
 Multiple choice, short answer/essay, probemsolving questions.
 Bring pencils, picture ID; we may check ID
before you hand in exams.
Missing exams, classes, and
discussion sections
 Not allowed except under special
circumstances. See Attendance and
Assessment Policy section of Schedule of
Classes for valid reasons.
 Contact me as soon as you know you will miss
an exam (or class with homework or possible inclass exercise) when you have a valid reason.
 Planned absences due by February 6.
 Documentation is required.
 You must contact me promptly to schedule
make-up. See syllabus for more info.
Discussion Sections
 130 points of course grade based on
this important part of the course.
 50 minutes long, meet once per week.
 Run by TA with general guidelines from
me. TA has my full authority!
 Review lectures, present problems and
material not in lecture.
 Quizzes and exercises.
 You must attend your scheduled section
– change through Registrar only.
Homework Assignments
 Assigned in class/on web, solutions on web.
 Due in class at 9:30 am.
 Must be typed (or neatly written) and stapled.
 Will not be accepted after the end of class.
 Read syllabus for details!
 First homework can be found on ELMS and is
due a week from today (Feb 5).
 You may discuss homework with classmates,
but final write-up must be in your words.
 No copying!
 List sources!
Extra Credit
 There will be no extra-credit papers.
 I may ask questions or give
assignments worth bonus points.
 Extra-credit questions may appear on
homework.
 Your TA may award extra credit in
section.
University of Maryland Honor Pledge
I pledge on my honor that I have not
given or received any unauthorized
assistance on this examination.
Academic Integrity
 This is serious!!!
 Abide by Code of Academic Integrity.
 Academic dishonesty includes:
 Cheating.
 Plagiarism.
 Facilitating.
 Fabrication.
 A few specific examples:
 Copying homework from a friend or from a book.
 Allowing your work to be copied.
 Cheating on tests.
Academic Integrity
 We may refer cases to the Student
Honor Council…
 You may get an XF course grade.
 For further information:
 See syllabus.
 Read Code of Academic Integrity
 In Academic Info section of Schedule of Classes
 Or in Undergraduate Catalog
 Or on the web versions of these.
ASTR100 (Spring 2008)
Introduction to Astronomy
Our Place in the Universe
Prof. D.C. Richardson
Sections 0101-0106
Our Modern View of the Universe
What is our physical place in the universe?
 Our “Cosmic Address”
Star
A large, glowing ball of gas that generates heat and
light through nuclear fusion
Planet
Mars
Neptune
A moderately large object that orbits a star; it shines by
reflected light. Planets may be rocky, icy, or gaseous in
composition.
Moon (or satellite)
An object that orbits a
planet.
Ganymede (orbits Jupiter)
Asteroid
A relatively small
and rocky object that
orbits a star.
Ida
Comet
A relatively
small and icy
object that
orbits a star.
Solar (Star) System
A star and all the material that orbits it, including its planets
and moons
Nebula
An interstellar cloud
of gas and/or dust
Galaxy
A great island of stars in space, all held
together by gravity and orbiting a common
center
M31, The Great Galaxy
in Andromeda
Universe
The sum total of all matter and energy;
that is, everything within and between
all galaxies
The Scale of the Universe
How big is Earth compared to our solar system?
Let’s reduce the size of the solar system by a factor of 10
billion; the Sun is now the size of a large grapefruit (14 cm
diameter).
How big is Earth on this scale?
A.
B.
C.
D.
an atom
a ball point
a marble
a golf ball
How big is Earth compared to our solar system?
Let’s reduce the size of the solar system by a factor of 10
billion; the Sun is now the size of a large grapefruit (14 cm
diameter).
How big is Earth on this scale?
A.
B.
C.
D.
an atom
a ball point
a marble
a golf ball
The scale of the solar system
 On a 1-to-10
billion scale:
 Sun is the
size of a
large
grapefruit
(14 cm)
 Earth is
the size of
a ball
point, 15
meters
away.
Relative Sizes of the Planets
How far away are the stars?
On our 1-to-10 billion scale, it’s just a few minutes walk to
Pluto.
How far would you have to walk to reach Alpha Centauri?
A.
B.
C.
D.
1 mile
10 miles
100 miles
the distance across the U.S. (2500
miles)
Answer: D, the distance across the U.S.
How big is the Milky Way Galaxy?
The Milky
Way has
about 100
billion stars.
On the same
ten billion-toone scale…
Suppose you tried to count the more than 100
billion stars in our galaxy, at a rate of one per
second…
How long would it take you?
A.
B.
C.
D.
a
a
a
a
few
few
few
few
weeks
months
years
thousand years
Suppose you tried to count the more than 100
billion stars in our galaxy, at a rate of one per
second…
How long would it take you?
A.
B.
C.
D.
a few weeks
a few months
a few years
a few thousand years
How big is the (Observable) Universe?
• The Milky Way is one of about 100 billion galaxies.
• 1011 stars/galaxy x 1011 galaxies = 1022 stars
As many stars as grains of (dry) sand on all Earth’s beaches…
 Now let’s step through the Universe in
powers of 10: