Download Welcome! Astronomy 100 / 190Y Exploring the Universe (Section A)

Astronomy 100 / 190Y
Exploring the Universe (Section A)
Welcome!
Why bother with Astronomy?
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Astronomy is a science, strongly rooted in physics and
mathematics.
We live in a complex society where science and quantitative
reasoning play an ever-increasing role.
It is crucial to understand how science and scientists actually
work, understand the power and limitations of the scientific
investigation, and learn how think logically and quantitatively.
Even more important, creativity and imaginative thinking are
becoming essential to succeed in all aspects of today s life. This
is what studying astronomy is all about: curiosity, creativity,
imagination.
Perhaps this course will spark a life-long interest in science;
perhaps not. In any event, the thought processes and reasoning
skills you develop this semester should stand you in good stead
in situations far surpassing this single course.
Why two names? (100/190Y)
n  The
Astro 100 section is the 4-credits
course
n  The Astro 190Y section is the 3-credits
course
n  Please, make sure you are enrolled in the
section you are interested in (4 credits or 3
credits)
Astronomy 100/190Y –
Exploring the Universe
http://www.astro.umass.edu/~calzetti/astro100
Instructor: Prof. Daniela Calzetti
LGRT – B524
[email protected]
413. 545.3556
TA: Ms. Kathryn Grasha
LGRT - C531C,
[email protected]
Your professor works extensively with the Hubble Space
Telescope, a NASA/ESA mission
www.stsci.edu/outreach/
She is member of a team that
built a new instrument for
the Hubble, and which was
installed during the 4th
Shuttle Servicing Mission
in May 2009
She works on understanding
how gas can be
transformed into stars,
across the Universe and
time.
Section A – Fall 2011
n  Class
times –Tu-Th: 9:30 – 10:45 am
n  Office hours:
u  Prof. Calzetti: Tu: 11:00 am – 1:00 pm (or by
appointment)
u  Ms. Grasha: Wed: 3:00-4:30 pm; Fri:
2:00-3:00 pm
n  Text: Pathways to Astronomy; authors:
Schneider & Arny
n  Web site (contains syllabus and updated infos):
http://www.astro.umass.edu/~calzetti/astro100
What is this course about?
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In the course of this semester, you will learn a lot of new
concepts related to our understanding of the Cosmos, and
any limitations we still have to that understanding.
Together with that, and hopefully more lastingly, you will:
u  become familiar with (and conversant about) the
fundamental constituents of the Universe.
u  acquire tools which will allow you to better understand
the world (universe) around you.
u  develop an understanding (and, hopefully, an
appreciation) of how science works and how we know
what we know.
Earth: one of the ~400 planets we know about today! (and counting)
Not to scale!
EARTH
MOON
Our Solar System
Our Sun, one of many stars
Our Sun is a very `quiet star. Other stars are a lot more energetic
and affect their surroundings much more drastically
Planets and stars are parts of `flattened structures called galaxies.
Galaxies are varied in shapes,
sizes, luminosity, …
… and sometimes they group in clusters.
No Dark Energy, no Supernova evolution
Philosophy
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My task is to introduce and explain new ideas and
concepts to you; NOT to read the textbook to you!
u 
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Not everything from the reading will be covered in class; however,
we cover most of it, especially the most difficult parts. Important:
you are responsible for all the material in the syllabus
My job is to find ways to help you learn about
science and astronomy, your job is to actively do
the learning!
Philosophy
n 
Class will be, as much as possible, an interactive
experience.
u  So come prepared and with an open mind:
t  to discuss the material from the readings
•  Always read the assigned chapters before coming to the next
lecture!
t 
to ask questions
•  Remember: the only stupid questions are those that are never asked!
(there are stupid answers, though)
t 
to help your classmates
•  Help during in-class discussions, and during homeworks
Course Organization:
The lecture course is organized into four broad topics
(syllabus is available from website):
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Naked-Eye Astronomy: You probably know
more than you think (~5 lectures)
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Tools of Astronomy: The Physics of Light;
Spectra; Telescopes (~8 lectures)
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Stars: Their birth, life, and death (~5 lectures)
Galaxies and Cosmology: The Origin and
Fate of the Universe (~4 lectures)
The 4-credits portion:
A separate `Lab portion is required for those enrolled
in the 4-credit course (Astro 100 - 36515):
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Instructor: Prof. Tom Burbine
Location: Hasbrouck Lab 20
Days/Times: either Mo or Wed, every other week;
4:40-5:30 pm
First Class: Wed Sept. 7th (Wed. class) or Mon Sept
12th (Mon. class)
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Program: Hands-on experiments!
Lab Assignments: on the lab’s SPARK page.
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Website: http://blogs.umass.edu/astron100-tburbine/
Lecture Course Requirements
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Attendance is required and is the single most
important way to ensure success in this course.
Experience shows that it is difficult to pass this
class without attending the lectures and
discussions.
Reading assignments are posted on the class web
site and are listed at the end of each lecture. You
will have a reading assignment for every lecture.
Lectures: PDFs will be posted on the website,
roughly following the in-class portion
Lecture Course Requirements
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Homework:
8 homeworks, each worth 2.5% of final grade, for a total
worth of 20% of final grade
u  One day late => ½ credit
u  More than one day late => no credit.
Internet Access: You will need internet access to have
access to the homework.
Cooperation (working together) is strongly encouraged.
Homework will be administered through the OWL system.
You ll be able to access your OWL account through your
SPARK account (by clicking on the Powerlink).
t  Owl login = 8 digit student ID
t  Owl passwd = last name
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Lecture Course Requirements
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Exams:
u  3 one hour in-class (mid-term) exams + 1 final
u  the 3 mid-term exams are each worth 15% of
the final grade; the final exam will be worth
20% of your final grade;
u  exams are `open book /`open notes
Makeup exams will be given only for documented
medical or family emergencies or by prior
arrangement. Makeup exams may be essay-style
or oral.
Lecture Course Requirements
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In-Class Quizzes:
u  7 in-class quizzes, similar to in-class exams, but
much shorter in length (~10-15 minutes).
u  Each worth 2.5% of grade; only highest 6 will
be counted, thus worth 15% of the final grade;
u  For the quizzes, there will be a `open book /
`open notes policy. However, no student-tostudent information exchange!
Lecture Course Requirements
n  Academic
Honesty is expected of all
scientists, and also of all students of
science.
Lecture Course Requirements
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General Courtesy
u  This should not even need to be an issue.
t  turn cell phones and p.e.d.s off
t  come on time
t  do not chatter
u  Blatant and rude disruptions of class will result
in expulsion from class.
Grades
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Grades will be assigned on a modified straight scale. Scores will be
adjusted upward if the exams is too hard
Guaranteed minimum grade:
u  A:
92%
u  AB: 87%
u  B:
82%
u  BC: 77%
u  C: 72%
u  CD: 67%
u  D: 60%
Totals of components of Final Grade (100% for 3-credits; 75% for 4credits)
u  6 quizzes:
15%
u  3 1-hr exams: 45%
u  1 Final exam: 20%
u  8 Homeworks: 20%
Grades (For the Course+Lab)
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For those taking the 4-credit course, their final grade will
include the grade from the Lab Course
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The Lab grade will be COMBINED with the Course grade
to derive the final grade:
u  Final grade = 0.75 Grade(course) + 0.25 Grade(Lab)
u  The components for Grade(course) are those listed in
the previous slide
In-Class Participation
(a.k.a. Peer Instruction)
n  Participation
is key to a real understanding
of the concepts. In class you will:
u  answer survey questions
u  have thought-provoking discussions to
answer questions as a group
u  learn new concepts more quickly and
with deeper understanding
Survey Question
10 billion years from now, our beloved
planet will be long dead. If none of the others
happen beforehand, how will the Earth finally
meet its end?
1) a nearby star will supernova – irradiating
the planet with deadly high-energy
particles
2) our Sun will expand and engulf the Earth
in its 5000+ degree photosphere
3) a black hole will swallow-up our solar system
4) an asteroid will collide with the Earth
5) humans will screw up real bad
Survey Question
10 billion years from now, our beloved
planet will be long dead. If none of the others
happen beforehand, how will the Earth finally
meet its end?
1) a nearby star will supernova – irradiating
the planet with deadly high-energy
particles
2) our Sun will expand and engulf the Earth
in its 5000+ degree photosphere
3) a black hole will swallow-up our solar system
4) an asteroid will collide with the Earth
5) humans will screw up real bad
Announcements
General announcements will be given at
the beginning of each class
u  During the lecture also the textbook
Chapter(s) numbers to read for the
following class will be given, as Reading
Assignments.
u 
Reading Assignment
Chapters 1 and 2 of the textbook.
Goals for the Rest of Today
to understand and start using scientific
notation
l  to remember how to convert units!
l 
This is mostly a lecture about the `language of science
In order to describe and
understand what you see, you
need numbers and units
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Amherst:
UMass is about 1.5 miles
from the center;
Antonio’s pizza is about 1
pound (~0.45 kg) a slice
The town was founded
about 200 years ago
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The Universe:
The nearest star is 4 light
years away (1 ly=
9.45 1012 km = 5.88 1012
miles);
The mass of a black hole is
about 108 solar mass (1 solar
mass is about 2*1030 Kg)
The age of the Universe is
about 13.5 billion years
Metric System
Called the MKS system (meter, kilogram, second);
all other quantities defined as function of these
l  Very useful: different units are related by factors
of 10:
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1 km = 1,000 m
1 m = 100 cm
1 cm = 10 mm
1 kg = 1,000 g
not quite: 1 hr = 3,600 s, 1 yr = 31,536,000 s
The scales we meet in exploring the
Universe range from very big to very small
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we must learn how to deal with them:
we can have numbers that are as small as:
0.0000000000001 cm (size of the atom)
13,500,000,000 (years, age of the
Universe)
We need to remember them without `losing’
any zeros…
0.0000000000001 = 10-13
14,000,000,000 = 1.4 1010
Multiplying and dividing factors of 10 is easy!
a
b
( x !10 ) ! ( y !10 ) = ( x " y ) !10
a +b
Similarly,
(x%
a !b
( x "10 ) ÷ ( y "10 ) = && ## "10
' y$
a
b
For Example:
8
4
(6 !10 ) ÷ (2 !10 ) = 3 !10
4
Survey Question
Let’s assume that the budget deficit is about
$500 billion. If there are roughly 100
million households in the U.S., how much
debt would each household acquire if the
deficit were split evenly among them?
1) $50
2) $500
3) $5,000
4) $50,000
Scale is important in Math too!
106
+
3x106
But …
=
4x106
8
1,000,000
+ 3,000,000
4,000,000
4
10 + 10 ! 10
100,000,000
100,000,000
++ 10,000
10,000
100,010,000
100,010,000
8
Survey Question
For which of the following are x, y, and z closest in
value?
1) x = 109 + 109 , y = 105 ! 2 !10 4 , z = 3 !1011 / 10 2
2) x = 10 2 + 10 6 , y = 10 2 " 2 ÷10 8 ,z = 1011 /10 9
!
4
5
!
10
11
11
3) x = 103 " 103 , y =
,
z
=
10
/
10
10 2 !10 2
How to say big numbers
Billion
Million
Thousand
thousandth
millionth
billionth
Giga Mega
Kilo ... milli micro nano (G)
(M)
(K)
109
106
103
(m)
(µ)
(n)
10-3
10-6
10-9
Survey Question
How much does 1 billion dollar bills weigh?
(guess that $1000 weighs about 1kg)
1) one million kg
2) one hundred thousand kg
3) one thousand kg
4) one hundred kg
Survey Question
How tall is a stack of 1 billion dollar bills?
(guess that $100 is about 10mm high)
1) 100 mm
2) 100 cm
3) 100 m
4) 100 km