Lecture 1
ASTR 111 – Section 002
Introductory Astronomy:
Solar System
Dr. Weigel
Outline
1.
2.
3.
4.
Course Overview
Course Logistics and Syllabus
Angular Measurements
Accuracy vs. Precision
Course Overview
Topics
* Note *
I will send a link to these
lecture notes later today
Some slides will appear in
lecture that are not on
your print-outs.
Ashes to ashes,
dust to dust.
Gasses to gasses,
stardust to stardust?
How did the solar system form?
There is a theory which states that if ever
anyone discovers exactly what the universe is
for and why it is here, it will instantly disappear
and be replaced by something even more
bizarre and inexplicable.
There is another which states that this has
already happened.
Douglas Adams (1952-2001)
What are the
differences
between planets?
www.mattjonesblog.com/img/scale/SolScaleC.jpg
http://www.mattjonesblog.com/img/scale/SolScaleB.jpg
How does the sun interact with Earth?
Why does the sun follow a certain
path in the sky?
http://antwrp.gsfc.nasa.gov/apod/ap071222.html
Why do we have
eclipses?
Why are some
eclipses different?
http://apod.nasa.gov/apod/image/0604/eclipse2006_seip.jpg
http://antwrp.gsfc.nasa.gov/apod/ap080808.html
What causes the
moon’s phases?
Why do we have seasons?
http://www.whisperedhope.com/Images/seasons%20Of%20Life%20Large.jpg
Course Overview
General Information
• Astronomy 111 is designed to give you an
overview of the solar system and the methods of
astronomy.
• It has been developed for non-science majors
who wish to gain a better understanding of the
known universe, ancient and modern astronomy,
and methods for interpreting astronomical
observations and measurements.
• A mathematical background including high
school algebra, geometry, and trigonometry is
necessary to do well in this course.
Course Overview
How to succeed
• Come to class and participate
– 70% of success in life is just showing up –
Woody Allen
• Do the reading assignments
– The reading for this week is Chapter 1 (all)
and Chapter 2 (section 2.1-2.2 only).
• Take the quizzes
– The quiz for this week will only cover topics
discussed in lecture
Course Overview
Key goals
• I want you to understand the basic principles of
astronomy
• I want you to think critically
– Perspective of any employer: Baseline knowledge of
facts is helpful. But baseline knowledge will not help
you in new and unusual situations.
• I want you to be able to think like a scientist
– Simplify the complex by using basic principles
– Interact with other people to solve a problem
Outline
1.
2.
3.
4.
Course Overview
Course Logistics and Syllabus
Angular Measurements
Accuracy vs. Precision
Course Web Page, etc.
• I use both Blackboard and a separate web page.
• Lecture notes and syllabus:
http://aurora.gmu.edu/astr111
• Quizzes: http://gmu.blackboard.com. Assigned
Thursday, due Tuesday before class.
• Announcements via your regular GMU email. If you
do not receive an email before 10 pm tonight, send
me an email at rweigel@gmu.edu.
• You should receive an email from me every
Monday and Wednesday.
Step 1: Log-in
Step 2: Click Assessments
Exams and Quizzes
• Three exams + a final exam all
of equal weight
• Lowest score is dropped
• Quizzes count for 10% of final
grade
• Best three exam scores count
for 30% each
• Letter grades are
–
–
–
–
–
–
–
–
–
–
A
AB+
B
BC+
C
CD
F
=
=
=
=
=
=
=
=
=
=
93-100
90-93
87-90
83-87
80-83
77-80
73-77
70-73
60-70
0-60
Make-up Exams
No make-up exams
Contact
rweigel@gmu.edu
703-993-1361
The Office Hour
• After class
(Tues/Thurs 10:15-?)
• By appt. (send me
email)
Lecture Notes
• Lecture notes posted
the day before class.
• I will send an email to
your GMU account
when it is posted.
• I suggest printing out
the lecture notes (or
at least the in-class
exercises) prior to
class.
Do you need to take the lab?
• Probably
• See your academic advisor!
http://www.bio.psu.edu/people/faculty/strauss/anatomy/misc/Lab%201943.jpg
Textbook
8th Edition Cover
7th Edition Cover
Honor Code
• Student members of the George Mason
University community pledge not to cheat,
plagiarize, steal, or lie in matters related to
academic work.
http://ndn.newsweek.com/media/36/071005_SO02_vl-vertical.jpg
Lecture Structure
“I hear and I forget. I see and I remember. I do and I understand.”
http://www.thequoteblog.com/wp-content/uploads/2007/06/confucius.jpg
Attendance
Outline
1.
2.
3.
4.
Course Overview
Course Logistics and Syllabus
Angular Measurements
Accuracy vs. Precision
Angular Measurements
• Subdivide a circle into 360 degrees
1 degree
Astronomers use angles to denote the positions
and apparent sizes of objects in the sky
=Observer’s Zenith
• Astronomers use angular measure to describe the apparent
size of a celestial object—what fraction of the sky that object
seems to cover
• The angular diameter (or angular size) of the Moon is ½°
or the Moon subtends an angle of ½°.
If you draw lines from your eye to each of two
stars, the angle between these lines is the angular
distance between these two stars
The adult human hand held at arm’s length
provides a means of estimating angles
Angular Measurements
• Subdivide a circle into 360 degrees
1 degree
• Subdivide one degree into 60 arcminutes
– minutes of arc
– abbreviated as 60 arcmin or 60´
• Subdivide one arcminute into 60 arcseconds
– seconds of arc
– abbreviated as 60 arcsec or 60”
1° = 60 arcmin = 60´
1´ = 60 arcsec = 60”
What is 0.5 degrees?
• Using arcminutes and arcseconds?
What is 0.5 degrees?
• Using arcminutes and arcseconds?
0.5 degree 60 arcminutes

1
degree
What is 0.5 degrees?
• Using arcminutes and arcseconds?
0.5 degree 60 arcminutes

 30 arcminutes
1
degree
What is 0.5 degrees?
• Using arcminutes and arcseconds?
0.5 degrees 60 arcminutes 60 arcseconds


 1800 arcseconds
1
degree
arcminute
Group Questions
• Form groups of exactly 4
• Optimal configuration is two
students in one row and two
students in another row
No
Yes
No
http://antwrp.gsfc.nasa.gov/apod/image/0808/moongames_lavederN080717_9416.jpg
Turn in one card per group … if you disagree on answer,
write down what you disagreed about
•
•
•
•
Name, seat #, and height
Name, seat #, and height
Name, seat #, and height
Name, seat #, and height
• Question 1 Answer
• Question 3 Answer
• Question 4 Answer
• Question 2 Answer
Front side
Back side
Turn in one card per group … if you disagree on answer,
write down what you disagreed about
•
•
•
•
Name, seat #, and height
Name, seat #, and height
Name, seat #, and height
Name, seat #, and height
• Question 1 Answer
• Question 3 Answer
• Question 4 Answer
Me
Row 1, seat N
Row 1, seat 1
• Question 2 Answer
Row 2, seat N
Front side
Row 2, seat 1
Back side
A
B
1. What is the angular distance between points A
and B on this slide (In degrees and
arcminutes). Each student should take their
own measurement.
2. Predict what will happen if you made your
measurement in two different parts of the
room.
3. Next week you sit in the same chair but weigh
30 pounds less. Will your (angular)
measurements change?
4.
Do you think there will be a relationship between a
persons height and the angle they measure?
A
B
1. What is the angular distance between points A
and B on this slide (In degrees and
arcminutes). Each student should take their
own measurement.
2. Predict what will happen if you made your
measurement in two different parts of the
room.
3. Next week you sit in the same chair but weigh
30 pounds less. Will your (angular)
measurements change?
4.
Do you think there will be a relationship between a
persons height and the angle they measure?
http://antwrp.gsfc.nasa.gov/apod/ap071025.html
Before you leave
• Turn in cards at front of room. One card
per group.
• Is this a graded assignment? No.